Blessy's Blog

HyperLink in Reapeater Control ASP.NET

2013-11-08T02:34:00.003-08:00

Add a HyperLink to a Reapeater Control in ASP.NET

Place a Repeater control on a form.

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Repeater ID="Repeater1" runat="server">
<HeaderTemplate>
<table>
<th>ID</th>
<th>name</th>
<th>marks</th>
</HeaderTemplate>
<ItemTemplate>
<tr>
<td> <asp:Label ID="Label1" runat="server" Text='<%#Eval("rollno")%>'></asp:Label></td>

<td> <%#Eval("name") %></td>
<td> <%#Eval("marks") %></td>
<td>
<asp:HyperLink ID="HyperLink1" runat="server" NavigateUrl ='<%#DataBinder.Eval(Container.DataItem,"rollno","show.aspx?id={0}")%>'>Go</asp:HyperLink></td>
</tr> </ItemTemplate>
</asp:Repeater>
</div>
</form>
</body>

</html>

Now Create a connect class

public class Connect

{

SqlConnection con;

public Connect()

{

con = new SqlConnection("Data Source=.;Initial Catalog=[DatabaseName];Integrated Security=True");

}

public DataTable Select()

{

SqlDataAdapter ad = new SqlDataAdapter("select * from stud", con);

DataSet ds = new DataSet();

ad.Fill(ds, "stud");

return ds.Tables[0];

}

In the code behind

public partial class repeater : System.Web.UI.Page

{

Connect c = new Connect();

protected void Page_Load(object sender, EventArgs e)

{

if (!IsPostBack)

{

bind();

}

private void bind()

{

Repeater1 .DataSource =c.Select();

DataBind();

}

Create another Webform named show.aspx

</head>

<body>

<div>

</div>

<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>

</form>

</body>

</html>

Just retrieve the Query string aand display it

public partial class show : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e)

{

Label1.Text = "RollNo: " + Request.QueryString["id"];

}

If you want you can provide more styles to repeater. Enjoy!!!

Adding checkbox in Gridview

2013-11-08T02:22:00.002-08:00

Gridview CheckBox

In a form place a Gridview and edit columns. In the TemplateField add a CheckBox.
Add BoundFileds to connect to database values. My table is as follows

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
BackColor="White" BorderColor="#999999" BorderStyle="None" BorderWidth="1px"
CellPadding="3" GridLines="Vertical" DataKeyNames="rollno">
<AlternatingRowStyle BackColor="#DCDCDC" />
<Columns>
<asp:TemplateField HeaderText="select">
<ItemTemplate>
<asp:CheckBox ID="chklist" runat="server" />
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="rollno" HeaderText="ID" />
<asp:BoundField DataField="name" HeaderText="Name" />
<asp:BoundField DataField="marks" HeaderText="Marks" />
</Columns>
<FooterStyle BackColor="#CCCCCC" ForeColor="Black" />
<HeaderStyle BackColor="#000084" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="#999999" ForeColor="Black" HorizontalAlign="Center" />
<RowStyle BackColor="#EEEEEE" ForeColor="Black" />
<SelectedRowStyle BackColor="#008A8C" Font-Bold="True" ForeColor="White" />
<SortedAscendingCellStyle BackColor="#F1F1F1" />
<SortedAscendingHeaderStyle BackColor="#0000A9" />
<SortedDescendingCellStyle BackColor="#CAC9C9" />
<SortedDescendingHeaderStyle BackColor="#000065" />
</asp:GridView>
<asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Select"
Height="26px" />
<p>
<asp:Literal ID="Literal1" runat="server"></asp:Literal>
</p>
<asp:GridView ID="GridView2" runat="server" AutoGenerateColumns="False" DataKeyNames="rollno">
<Columns>
<asp:TemplateField>
<EditItemTemplate>
<asp:CheckBox ID="CheckBox1" runat="server" />
</EditItemTemplate>
<ItemTemplate>
<asp:CheckBox ID="CheckBox1" runat="server" />
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="rollno" HeaderText="RollNo" />
<asp:BoundField DataField="name" HeaderText="name" />
<asp:BoundField DataField="marks" HeaderText="Mark" />
<asp:CommandField ShowEditButton="True" />
</Columns>
</asp:GridView>

Create a Connect Class

using System.Data.SqlClient;
using System.Data;
public class Connect
{
SqlConnection con;
public Connect()
{
con = new SqlConnection(@"Data Source=.;Initial Catalog=[Dbname];Integrated Security=True");

}

public DataTable Select()
{
SqlDataAdapter ad = new SqlDataAdapter("select * from stud", con);
DataSet ds = new DataSet();
ad.Fill(ds, "stud");
return ds.Tables[0];
}
}

Now In the code behind create the following code

public partial class _Default : System.Web.UI.Page
{
Connect c = new Connect();
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
bind();
}
}

private void bind()
{

GridView1.DataSource = c.Select();
DataBind();
}
protected void Button1_Click(object sender, EventArgs e)
{
string str = string.Empty;
string name = "";
foreach (GridViewRow gr in GridView1.Rows)
{
CheckBox ck = (CheckBox)gr.FindControl("chklist");
if (ck != null && ck.Checked )
{
str += GridView1.DataKeys[gr.RowIndex].Value.ToString() + " ";
name += gr.Cells[2].Text+" ";
}
}
Literal1.Text ="selected:"+ str + "<br/>" + name;
}

}

Now Save and Run the program

Enjoy!!

Regular Expressiona in c#

2013-07-22T03:02:00.000-07:00

Regular Expressions

A regular expression is a set of characters that can be compared to a string to determine whether the string meets specified format requirements. You can also use regular expressions to extract portions of the text or to replace text.

Which uses the System.Text.RegularExpressions namespace, performs this check using the static method System. Text.RegularExpressions.Regex.IsMatch method

How to Use Regular Expressions for Pattern Matching
Example:-
“^\d{5}$” => means that the string must be exactly five numeric digits.
"^" => Match beginning of input
"\d" => Match only numeric digits
"{5}" => Match exactly 5 characters
"$" => Match end of input

Regular expressions can be used to match complex input patterns, too.

Regular expressions are an extremely efficient way to check user input,
However, Regular expressions are difficult to create unless you are extremely familiar with the format.

"\d" => "[0-9]" => Matches a digit character.
"\d{3}" => "[0-9]{3} => Matches 3 digit character.
(< 3 and > 3 are Invalid)
"\d{2,5}" => "[0-9]{2,5} => Matches 1 to 5 digit character
(< 2 and >5 are Invalid)
"\D" => "[^0-9]" => Matches a non digit character.
"\s" => "[\f\n\r\t\v]" => Matches any white-space character.
(Space, Tab and form-feed)
"\S" => "[^\f\n\r\t\v]" => Matches any non-white-space character.
"\w" => "[A-Za-z0-9]" => Matches any word character including underscore.
"\W" => "[^A-Za-z0-9]" => Matches any non word character, including underscore.

How to Extract Matched Data

Besides simply determining whether a string matches a pattern, you can extract information from a string. For example, if you are processing a text file that contains “CompanyName: Contoso, Inc.”, you could extract just the company name using a regular expression.

To match a pattern and capture the match, follow these steps:

1. Create a regular expression, and enclose in parentheses the pattern to be matched.
2. Create an instance of the System.Text.RegularExpressions.Match class using the static Regex. Match method.
3. Retrieve the matched data by accessing the elements of the Match. Groups array.

EXAMPLE 1

string input = "Company Name: Contoso, Inc.";
Match m = Regex.Match(input, @"Company Name: (.*$)");
MessageBox.Show (m.Groups[1].ToString());

EXAMPLE 2
Email Phone number validation

Regex r = new Regex(@"\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*");

Regex r2=new Regex( @"^\d{4}(\-\d{7})?$");

// @"^$?(\d{3})$?[\s\-]?(\d{3})\-?(\d{4})$"); international code
if (r.IsMatch(txtMail.Text))
{
MessageBox.Show("Valid");
}

else
{
MessageBox.Show("Invalid Email");
}

if(r2.IsMatch(textBoxPhNo.Text))
{
MessageBox.Show("Valid");
}

else
{
MessageBox.Show("Invalid phone number");

}

EXAMPLE 3

3 DIGIT NUMBER VALIDATION

Regex x = new Regex(@"^[0-9]{1,3}$");
// Regex x = new Regex(@"^\d{3}$");

if (x.IsMatch(txtNo.Text))
{
MessageBox.Show("Valid");
}

else
{
MessageBox.Show("Invalid");

}
Summary

■ Regular expressions enable you to determine whether text matches almost any type of format. Regular expressions support dozens of special characters and operators. The most commonly used are “^” to match the beginning of a string, “$” to match the end of a string, “?” to make a character optional, “.” to match any character, and “*” to match a repeated character.

■ To match data using a regular expression, create a pattern using groups to specify the data you need to extract, call Regex .Match to create a Match object, and then examine each of the items in the Match. Groups array.

LINQ

2013-06-23T21:28:00.003-07:00

Language Integrated Query (LINQ)

LINQ is a programming model that is the composition of general-purpose standard query operators that allow you to work with data, regardless of the data source in any .NET based programming language. It is the name given to a set of technologies based on the integration of query capabilities into any .NET language.

What are the three main components of LINQ or Language INtegrated Query?

1. Standard Query Operators

2. Language Extensions

3. LINQ Providers

How are Standard Query Operators implemented in LINQ?

Standard Query Operators are implemented as extension methods in .NET Framework. These Standard Query Operators can be used to work with any collection of objects that implements the IEnumerable interface. A class that inherits from the IEnumerable interface must provide an enumerator for iterating over a collection of a specific type. All arrays implement IEnumerable. Also, most of the generic collection classes implement IEnumerable interface.

How are Standard Query Operators useful in LINQ?

Standard Query Operators in LINQ can be used for working with collections for any of the following and more.

1. Get total count of elements in a collection.

2. Order the results of a collection.

3. Grouping.

4. Computing average.

5. Joining two collections based on matching keys.

6. Filter the results

List the important language extensions made in C# to make LINQ a reality?

1. Implicitly Typed Variables

2. Anonymous Types

3. Object Initializers

4. Lambda Expressions

What is the purpose of LINQ Providers in LINQ?

LINQ Providers are a set of classes that takes a LINQ query and dynamically generates a method that executes an equivalent query against a specific data source.

What are the four LINQ Providers that .NET Framework ships?

1. LINQ to Objects - Executes a LINQ query against a collection of objects

2. LINQ to XML - Executes an XPATH query against XML documents

3. LINQ to SQL - Executes LINQ queries against Microsoft SQL Server.

4. LINQ to DataSets - Executes LINQ queries against ADO.NET DataSets.

What are the advantages of LINQ over Stored Procedures?

Below is the three advantages of LINQ over stored procedures.

Debugging - As debug point concern, as LINQ is part of .NET, we can use the visual studio's debugger to debug the queries but it is tough to debug the Stored procedure as it will not support the visual studio debugger.

Deployment - In case of deployment, we need to provide an additional script for stored procedures to execute but in case of LINQ, it will complie into single DLL hence deployment becomes easier.

Type Safety - As LINQ is type safe, the queries errors are type checked at compile time. Better suggest to use LINQ because it helps to encounter an error at the compile time rather than at

runtime exception.

What is the difference between FirstOrDefault() and SingleOrDefault() extension method in LINQ

FirstOrDefault() = gets the first item that matches a given criteria.

SingleOrDefault() = if you specify this extension method that means you are specifically saying that there can be only one value that matches the criteria. If there are more then 1 value that matches the criteria, throw an exception.

What is the disadvantage of LINQ over stored procedures?

The disadvantage with LINQ is, it is not a precompiled statement where as stored procedures are precompiled. In case of LINQ the queries need to be compile before the execution. So according to this, stored procedures are faster in performance as compared to LINQ

What is the difference between First() and Single() extension methods in LINQ ?

• First() - There is at least one result, an exception is thrown if no result is returned.

• Single() - There is exactly 1 result, no more, no less, an exception is thrown if no result is returned.

What is the DataContext class and how is it related to LINQ?

After you add a LINQ to SQL Classes item to a project and open the O/R Designer, the empty design surface represents an empty DataContext class ready to be configured. The DataContext class is a LINQ to SQL class that acts as a conduit between a SQL Server database and the LINQ to SQL entity classes mapped to that database. This class contains the connection string information and the methods for connecting to a database and manipulating the data in the database. It is configured with connection information provided by the first item that is dragged onto the design surface.

Write a program using LINQ to find the sum of first 5 prime numbers?

javascript in ASP.NET

2013-03-27T02:10:00.003-07:00

learn javascript in asp.net

Introduction

de facto standard for client-side Web development
Enable to build robust applications in combination with ASP.NET
Mainly used to compensate limitations of ASP.NET in terms of usage of custom controls
JavaScript can allow you to create new things on your website that are both dynamic and interactive, allowing you to do things like find out some information about a user (like monitor resolution and browser), check that forms have been filled in correctly, rotate images, make random text, do calculations and many other things.

Inserting JavaScript into an ASP.NET Page

Steps:

Define the script block that contains the JavaScript function.

Insert the script block programmatically:using the Page.RegisterStartupScript() or the Page.RegisterClientScriptBlock() method.

Adding JavaScript to a Server Control

Illustrating with the help of a real world example.

Button control in ASP.NET to generate the current time:

Button1.Value = DateTime.Now.ToString();

Note:ASP.NET page here gets the time from the server that generated the page.

What if you wanted the button to show the time of the person viewing the page? The easiest way of accomplishing this task would be to do this using JavaScript on the client-side.

<%@ Page Language="C#" %>

void Button1_Click(object sender, EventArgs e)

{

Response.Write("Postback!");

}

</script>

<html>

<p>

<asp:Button id="Button1" onclick="Button1_Click"

runat="server" Font-Bold="True" Font-Names="Verdana"

Font-Size="Larger"></asp:Button>

</p>

</form>

</body>

</html>

Button showing the current time:

Performing a Simple Button-rollover

Hover mouse over a button

Useful for Web pages that have multiple buttons

Code:

<%@ Page Language="C#" %>

void ImageButton1_Click(object sender, ImageClickEventArgs e)

{

Label1.Text = "Postback!";

}

</script>

<html>

<body>

<p>

<asp:ImageButton id="ImageButton1” onmouseover="this.src='button2.jpg‘ "

onclick="ImageButton1_Click“ onmouseout="this.src='button1.jpg‘ "

runat="server“ ImageUrl="button1.jpg"></asp:ImageButton>

</p>

<p>

<asp:Label id="Label1" runat="server" />

</p>

</form>

</body>

</html>

Setting Control Focus

Seting focus on particular control

//to set focus on first textbox when there are multipile textboxes on a web page

Changing the Control Focus Dynamically

Turn the <body> tag into a HTML server control

Placing code constructs in ASP.NET server-side events.

Body1.Attributes["onload"] = “document.forms[0][‘TextBox2’].focus();";

Keeping JavaScript in a Separate File (.js)

It is highly recommended to keep javascript in a seperate file.

Code to include .js file in ASP.NET page:

Page.RegisterClientScriptBlock("MyScript",

"<script language=javascript src='MyJavaScriptFile.js'>");

JavaScript Tutorial

2013-03-27T00:03:00.001-07:00

Javascript online tutorial

Javascript tutorial

JavaScript Introduction

JavaScript is the most popular scripting language on the internet, and works in all major browsers, such as Internet Explorer, Firefox, Chrome, Opera, and Safari.

Definition of JavaScript

• JavaScript was designed to add interactivity to HTML pages
• JavaScript is a scripting language
• A scripting language is a lightweight programming language
• JavaScript is usually embedded directly into HTML pages
• JavaScript is an interpreted language (means that scripts execute without preliminary compilation)
• Everyone can use JavaScript without purchasing a license

Java and JavaScript are two completely different languages in both concept and design!

Java (developed by Sun Microsystems) is a powerful and much more complex programming language - in the same category as C and C++.

The scope of JavaScript

• JavaScript gives HTML designers a programming tool - HTML authors are normally not programmers, but JavaScript is a scripting language with a very simple syntax! Almost anyone can put small "snippets" of code into their HTML pages

• JavaScript can put dynamic text into an HTML page - A JavaScript statement like this:
document.write("<h1>" + name + "</h1>") ;
can write a variable text into an HTML page

• JavaScript can react to events - A JavaScript can be set to execute when something happens, like when a page has finished loading or when a user clicks on an HTML element

• JavaScript can read and write HTML elements - A JavaScript can read and change the content of an HTML element

• JavaScript can be used to validate data - A JavaScript can be used to validate form data before it is submitted to a server. This saves the server from extra processing

• JavaScript can be used to detect the visitor's browser - A JavaScript can be used to detect the visitor's browser, and - depending on the browser - load another page specifically designed for that browser

• JavaScript can be used to create cookies - A JavaScript can be used to store and retrieve information on the visitor's computer

Example 1

<html>
<body>

<h1>My First Web Page</h1>

<script type="text/javascript">
document.write("<p>" + Date() + "</p>");
</script>

</body>
</html>

Example 2

<html>
<body>

<h1>My First Web Page</h1>

<p id="demo"></p>

<script type="text/javascript">
document.getElementById("demo").innerHTML=Date();
</script>

</body>
</html>

Example 3

<html>
<head>
<script type="text/javascript">
function displayDate()
{
document.getElementById("demo").innerHTML=Date();
}
</script>
</head>
<body>
<h1>My First Web Page</h1>
<p id="demo"></p>
<button type="button" onclick="displayDate()">Display Date</button>
</body>
</html>

Scripts in <head> and <body>

You can place an unlimited number of scripts in your document, and you can have scripts in both the body and the head section at the same time.
It is a common practice to put all functions in the head section, or at the bottom of the page. This way they are all in one place and do not interfere with page content.
Using an External JavaScript
JavaScript can also be placed in external files.
External JavaScript files often contain code to be used on several different web pages.
External JavaScript files have the file extension .js.
Note: External script cannot contain the <script></script> tags!
To use an external script, point to the .js file in the "src" attribute of the <script> tag:

Example

<html>
<head>
<script type="text/javascript" src="xxx.js"></script>
</head>
<body>
</body>
</html>

JavaScript is Case Sensitive

Unlike HTML, JavaScript is case sensitive - therefore watch your capitalization closely when you write JavaScript statements, create or call variables, objects and functions.

Example

<script type="text/javascript">
document.write("<h1>This is a heading</h1>");
document.write("<p>This is a paragraph.</p>");
document.write("<p>This is another paragraph.</p>");
</script>

JavaScript Comments

Single line comments start with //.
Multi line comments start with /* and end with */.

JavaScript Variables

JavaScript variables are used to hold values or expressions.
A variable can have a short name, like x, or a more descriptive name, like carname.
Rules for JavaScript variable names:
• Variable names are case sensitive (y and Y are two different variables)
• Variable names must begin with a letter or the underscore character.

Example

<html>
<body>
<script type="text/javascript">
var firstname;
firstname="Hege";
document.write(firstname);
document.write("<br />");
firstname="Tove";
document.write(firstname);
</script>
<p>The script above declares a variable,assigns a value to it, displays the value, changes the value,and displays the value again.</p>
</body>
</html>

JavaScript Arithmetic Operators

Operator Description

+ Addition
- Subtraction
* Multiplication
/ Division
% Modulus (division remainder)
++ Increment
-- Decrement

JavaScript Assignment Operators

Operator Example

= x=y
+= x+=y
-= x-=y
*= x*=y
/= x/=y
%= x%=y

The + Operator Used on Strings

The + operator can also be used to add string variables or text values together.
To add two or more string variables together, use the + operator.
Example
txt1="What a very";
txt2="nice day";
txt3=txt1+txt2;
Adding Strings and Numbers

The rule is: If you add a number and a string, the result will be a string!

Example

x=5+5;
document.write(x);

x="5"+"5";
document.write(x);

x=5+"5";
document.write(x);

x="5"+5;
document.write(x);

Comparison Operators

Operator Description

== is equal to
=== is exactly equal to (value and type)
!= is not equal
> is greater than
< is less than
>= is greater than or equal to
<= is less than or equal to

Logical Operators

Operator Description

&& and
|| or
! not

Conditional Operator

Syntax

variablename=(condition)?value1:value2

Example

greeting=(visitor=="PRES")?"Dear President ":"Dear ";

Conditional Statements

In JavaScript we have the following conditional statements:
• if statement - use this statement to execute some code only if a specified condition is true
• if...else statement - use this statement to execute some code if the condition is true and another code if the condition is false
• if...else if....else statement - use this statement to select one of many blocks of code to be executed
• switch statement - use this statement to select one of many blocks of code to be executed

If Statement

Syntax

if (condition)
{
code to be executed if condition is true
}

Example

<script type="text/javascript">
//Write a "Good morning" greeting if
//the time is less than 10

var d=new Date();
var time=d.getHours();

if (time<10)
{
document.write("<b>Good morning</b>");
}
</script>

If...else Statement

Syntax

if (condition)
{
code to be executed if condition is true
}
else
{
code to be executed if condition is not true
}

Example

<script type="text/javascript">
//If the time is less than 10, you will get a "Good morning" greeting.
//Otherwise you will get a "Good day" greeting.

var d = new Date();
var time = d.getHours();

if (time < 10)
{
document.write("Good morning!");
}
else
{
document.write("Good day!");
}
</script>

If...else if...else Statement

Syntax

if (condition1)
{
code to be executed if condition1 is true
}
else if (condition2)
{
code to be executed if condition2 is true
}
else
{
code to be executed if neither condition1 nor condition2 is true
}

Example

<script type="text/javascript">
var d = new Date()
var time = d.getHours()
if (time<10)
{
document.write("<b>Good morning</b>");
}
else if (time>10 && time<16)
{
document.write("<b>Good day</b>");
}
else
{
document.write("<b>Hello World!</b>");
}
</script>

The JavaScript Switch Statement

Used in the place of multiple if statements.

Syntax

switch(n)
{
case 1:
execute code block 1
break;
case 2:
execute code block 2
break;
default:
code to be executed if n is different from case 1 and 2
}

Example

<script type="text/javascript">
//You will receive a different greeting based
//on what day it is. Note that Sunday=0,
//Monday=1, Tuesday=2, etc.

var d=new Date();
var theDay=d.getDay();
switch (theDay)
{
case 5:
document.write("Finally Friday");
break;
case 6:
document.write("Super Saturday");
break;
case 0:
document.write("Sleepy Sunday");
break;
default:
document.write("I'm looking forward to this weekend!");
}
</script>

JavaScript Popup Boxes

JavaScript has three kind of popup boxes: Alert box, Confirm box, and Prompt box.

Alert Box

An alert box is often used if you want to make sure information comes through to the user.
When an alert box pops up, the user will have to click "OK" to proceed.

Syntax

alert("sometext");

Example

<html>
<head>
<script type="text/javascript">
function show_alert()
{
alert("I am an alert box!");
}
</script>
</head>
<body>
<input type="button" onclick="show_alert()" value="Show alert box" />
</body>
</html>

Confirm Box

A confirm box is often used if you want the user to verify or accept something.
When a confirm box pops up, the user will have to click either "OK" or "Cancel" to proceed.
If the user clicks "OK", the box returns true. If the user clicks "Cancel", the box returns false.

Syntax

confirm("sometext");

Example

<html>
<head>
<script type="text/javascript">
function show_confirm()
{
var r=confirm("Press a button");
if (r==true)
{
alert("You pressed OK!");
}
else
{
alert("You pressed Cancel!");
}
}
</script>
</head>
<body>

<input type="button" onclick="show_confirm()" value="Show confirm box" />

</body>
</html>

Prompt Box

A prompt box is often used if you want the user to input a value before entering a page.
When a prompt box pops up, the user will have to click either "OK" or "Cancel" to proceed after entering an input value.
If the user clicks "OK" the box returns the input value. If the user clicks "Cancel" the box returns null.

Syntax

prompt("sometext","defaultvalue");

Example

<html>
<head>
<script type="text/javascript">
function show_prompt()
{
var name=prompt("Please enter your name","Harry Potter");
if (name!=null && name!="")
{
document.write("Hello " + name + "! How are you today?");
}
}
</script>
</head>
<body>

<input type="button" onclick="show_prompt()" value="Show prompt box" />

</body>
</html>

JavaScript Loops

In JavaScript, there are two different kind of loops:

• for - loops through a block of code a specified number of times
• while - loops through a block of code while a specified condition is true

Syntax

for (variable=startvalue;variable<=endvalue;variable=variable+increment)
{
code to be executed
}

Example

<html>
<body>
<script type="text/javascript">
var i=0;
for (i=0;i<=5;i++)
{
document.write("The number is " + i);
document.write("<br />");
}
</script>
</body>
</html>

The while Loop

The while loop loops through a block of code while a specified condition is true.

Syntax

while (variable<=endvalue)
{
code to be executed
}

Example

<html>
<body>
<script type="text/javascript">
var i=0;
while (i<=5)
{
document.write("The number is " + i);
document.write("<br />");
i++;
}
</script>
</body>
</html>

The do...while Loop

The do...while loop is a variant of the while loop. This loop will execute the block of code ONCE, and then it will repeat the loop as long as the specified condition is true.

Syntax

do
{
code to be executed
}
while (variable<=endvalue);

Example

<html>
<body>
<script type="text/javascript">
var i=0;
do
{
document.write("The number is " + i);
document.write("<br />");
i++;
}
while (i<=5);
</script>
</body>
</html>

The break Statement

The break statement will break the loop and continue executing the code that follows after the loop (if any).

Example

<html>
<body>
<script type="text/javascript">
var i=0;
for (i=0;i<=10;i++)
{
if (i==3)
{
break;
}
document.write("The number is " + i);
document.write("<br />");
}
</script>
</body>
</html>

The continue Statement

The continue statement will break the current loop and continue with the next value.

Example
<html>
<body>
<script type="text/javascript">
var i=0
for (i=0;i<=10;i++)
{
if (i==3)
{
continue;
}
document.write("The number is " + i);
document.write("<br />");
}
</script>
</body>
</html>

Hope you enjoyed.. Happy Programming

Different Encryption Methods in C#

2013-03-26T02:20:00.003-07:00

C# training for Encryption Methods Encryption Methods in C#

1. Hashing
Hashing is a type of encryption in which we can only encrypt the data ,but can't decrypt it .

Here is the code implementation

import the following namespace:
using System.Security.Cryptography;

private void buttonGenerate_Click(object sender, EventArgs e)

{
UnicodeEncoding ue = new UnicodeEncoding();
byte[] normalPass = ue.GetBytes(textBoxPassword.Text);

MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider();
byte[] hashCode = md5.ComputeHash(normalPass);
labelHashCode.Text = Convert.ToBase64String(hashCode);

    }

2. Encryption Decryption

In the following program encryption and decryption is done based on an 8 bit key.

using System.Security.Cryptography;
using System.IO;
using System.Diagnostics;

namespace CryptoGraphyy
{
public partial class EncryptDecrypt : Form
{
static string EncrypData;

static byte[] bytes = System.Text.ASCIIEncoding.ASCII.GetBytes("HellOWor");

  private void buttonEncrypt_Click(object sender, EventArgs e)
{
try
{
DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
MemoryStream memoryStream = new MemoryStream();
CryptoStream cryptoStream = new CryptoStream(memoryStream, cryptoProvider.CreateEncryptor(bytes, bytes), CryptoStreamMode.Write);

StreamWriter writer = new StreamWriter(cryptoStream);
writer.Write(textBox1.Text);
writer.Flush();
cryptoStream.FlushFinalBlock();
writer.Flush();

EncrypData = Convert.ToBase64String(memoryStream.GetBuffer(), 0, (int)memoryStream.Length);
StreamWriter sw = new StreamWriter(@"C:\MyEncryption.txt");
sw.Write(EncrypData);
sw.Flush();
sw.Close();
MessageBox.Show("Data Encrypted!");

Process.Start("notepad",@"C:\MyEncryption.txt");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}

private void buttonDecrypt_Click(object sender, EventArgs e)
{
try
{
DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
MemoryStream memoryStream = new MemoryStream(Convert.FromBase64String(EncrypData));
CryptoStream cryptoStream = new CryptoStream(memoryStream, cryptoProvider.CreateDecryptor(bytes, bytes), CryptoStreamMode.Read);
StreamReader reader = new StreamReader(cryptoStream);

StreamWriter sw = new StreamWriter(@"C:\MyDecrypt.txt");
sw.Write(reader.ReadToEnd());
sw.Flush();
sw.Close();
MessageBox.Show("Data Decrypted!");
Process.Start("notepad", @"C:\MyDecrypt.txt");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}


}
}

3. Encryption and Decryption using Rijndael Algorithm

using System.IO;

using System.Security.Cryptography;

using System.Diagnostics;

namespace CryptoGraphyy

{

public partial class PasswordEncryption : Form

{

string passValue;

public PasswordEncryption()

{

InitializeComponent();

}

private void buttonEncrypt_Click(object sender, EventArgs e)

{

try

{

passValue = textBox1.Text;

RandomNumberGenerator rnd = RandomNumberGenerator.Create();

byte[] salt = new byte[16];

rnd.GetBytes(salt);

Rfc2898DeriveBytes derBytes = new Rfc2898DeriveBytes(passValue, salt);

byte[] key = derBytes.GetBytes(16);

Rijndael cryptoAlg = Rijndael.Create();

cryptoAlg.Key = key;

FileStream fs = new FileStream(@"d:\EncryptPass.txt", FileMode.Create);

fs.Write(salt, 0, salt.Length);

fs.Write(cryptoAlg.IV, 0, cryptoAlg.IV.Length);

CryptoStream cryptStream = new CryptoStream(fs, cryptoAlg.CreateEncryptor(), CryptoStreamMode.Write);

//Converting a string to an byte array

byte[] ar = System.Text.Encoding.UTF8.GetBytes(passValue);

cryptStream.Write(ar, 0, ar.Length);

cryptStream.FlushFinalBlock();

cryptStream.Close();

fs.Close();

MessageBox.Show("Data Encrypted");

Process.Start("notepad", @"d:\EncryptPass.txt");

}

catch (Exception ex)

{

MessageBox.Show(ex.Message);

}

private void buttonDecrypt_Click(object sender, EventArgs e)

{

try

{

passValue = textBox1.Text;

Rijndael deCryptoAlg = Rijndael.Create();

FileStream fs3 = new FileStream(@"d:\DecryptPass.txt", FileMode.OpenOrCreate);

FileStream fs2 = new FileStream(@"d:\EncryptPass.txt", FileMode.Open);

byte[] salt = new byte[16];

byte[] IV = new byte[deCryptoAlg.IV.Length];

fs2.Read(salt, 0, salt.Length);

fs2.Read(IV, 0, IV.Length);

Rfc2898DeriveBytes derByte = new Rfc2898DeriveBytes(passValue, salt);

byte[] key = derByte.GetBytes(16);

deCryptoAlg.Key = key;

deCryptoAlg.IV = IV;

CryptoStream cryStream = new CryptoStream(fs2, deCryptoAlg.CreateDecryptor(), CryptoStreamMode.Read);

int bytesRead = 0;

byte[] buffer = new byte[256];

{

bytesRead = cryStream.Read(buffer, 0, 256);

} while (bytesRead > 0);

fs3.Write(buffer, 0, 256);

fs3.Flush();

fs3.Close();

fs2.Close();

cryStream.Close();

MessageBox.Show("File Decrypted");

Process.Start("notepad", @"d:\DecryptPass.txt");

}

catch (Exception ex)

{

MessageBox.Show("Error"+ex.Message);

}

jQuery Effects

2013-03-26T01:44:00.004-07:00

Web Templates using JQuery Effects jQuery Effects

jQuery comes with a number of preset effects and the robust low-level
animation method for creating your own custom effects.
The preset effects include the following:
• Hiding and showing elements in a toggle fashion
• Scaling and simultaneously fading elements in and out of view
• Sliding up and down and toggling
• Fading in and out and to a specific opacity
All of the preset effects support speeds and callback functions to trigger upon
completion.
In addition to these predefined effects, there are also a number of utilities that can help
you take more control over your animations:
• :animated selector to assess whether an element is in the process of being animated
• The ability to turn off and on all effects across the board
• The ability to add to the animation queue with your own bespoke functions
• Function to change the entire queue of animations.

Sliding and Fading Elements in and out of View

Slide

The following are the slide methods :
• slideUp
• slideDown
• slideToggle

$(document).ready(function () {
$('#animate').click(function () {
$('.box').slideToggle('slow');
});
});

Fade

Fading

has the following methods:

• fadeIn
• fadeOut
• fadeTo

With the exception of fadeTo, all these methods take speed as the first parameter and
a callback function as the second—both of which are optional. The callback function
is executed once the animation is complete, and the context is set to the element the
animation ran against; i.e., the this variable is the current element .
Because there’s no opacity toggle function, either we can use a combination of

fadeIn and fadeOut:

$(document).ready(function () {
$('#animate').click(function () {
var $box = $('.box');
if ($box.is(':visible')) {
$box.fadeOut('slow');
} else {
$box.fadeIn('slow');
}
});
});

or we can create our own fade toggle animation, using the fadeTo method:

$(document).ready(function () {
$('#animate').click(function () {
$('.box').fadeTo('slow', 'toggle');
});
});

However,it reads better for future maintenance if we use the animate method:

$(document).ready(function () {
$('#animate').click(function () {
$('.box').animate({ opacity : 'toggle' }, 'slow');
});
});

Both

If we want to toggle the height and opacity together, we can reuse the previous
solution and add the height to toggle at the same time. This would cause the box to
fade out and slide up at the same time:

$(document).ready(function () {
$('#animate').click(function () {
$('.box').animate({
opacity : 'toggle',
height: 'toggle'
}, 'slow');
});
});

hide and show

With jQuery, you can hide and show HTML elements with the hide() and show() methods:

$("#hide").click(function(){
$("p").hide();
});

$("#show").click(function(){
$("p").show();
});

toggle

With jQuery, you can toggle between the hide() and show() methods with the toggle() method.

$("button").click(function(){
$("p").toggle();
});

Adapted from jQuery Cookbook, W3Schools

OOps interview Questions

2013-03-25T23:35:00.003-07:00

OOps interview Questions

1) What is meant by Object Oriented Programming?

OOP is a method of programming in which programs are organised as cooperative collections of objects. Each object is an instance of a class and each class belong to a hierarchy.

2) What is a Class?

Class is a template for a set of objects that share a common structure and a common behaviour. The keyword class in C# indicates that we are going to define a new class (type of object)

3) What is an Object?

Object is anything that is identifiable as a single material item. Object is an instance of a class. It has state,behaviour and identity. It is also called as an instance of a class.

4) What is an Instance?

An instance has state, behaviour and identity. The structure and behaviour of similar classes are defined in their common class. An instance is also called as an object.

5) What are the core OOP’s concepts?

Abstraction, Encapsulation,Inheritance and Polymorphism are the core OOP’s concepts.

6) What is meant by abstraction?

Abstraction defines the essential characteristics of an object that distinguish it from all other kinds of objects. Abstraction provides crisply-defined conceptual boundaries relative to the perspective of the viewer. Its the process of focussing on the essential characteristics of an object. Abstraction is one of the fundamental elements of the object model.

7) What is meant by Encapsulation?

Encapsulation is the process of compartmentalising the elements of an abtraction that defines the structure and behaviour. Encapsulation helps to separate the contractual interface of an abstraction and implementation.

8) What is meant by Inheritance?

It provides a convenient way to reuse existing fully tested code in different context thereby saving lot of coding. Inheritance is a relationship among classes, wherein one class shares the structure or behaviour defined in another class. This is called Single Inheritance. If a class shares the structure or behaviour from multiple classes, then it is called Multiple Inheritance. Inheritance defines “is-a” hierarchy among classes in which one subclass inherits from one or more generalised superclasses.

9) What is meant by Polymorphism?

Polymorphism literally means taking more than one form. Polymorphism is a characteristic of being able to assign a different behavior or value in a subclass, to something that was declared in a parent class.

10) What is an Abstract Class?

Abstract class is a class that has no instances. An abstract class is written with the expectation that its concrete subclasses will add to its structure and behaviour, typically by implementing its abstract operations.

There are scenarios in which it is useful to define classes that is not intended to instantiate; because such classes normally are used as base-classes in inheritance hierarchies, we call such classes abstract classes.

Abstract classes cannot be used to instantiate objects; because abstract classes are incomplete, it may contain only definition of the properties or methods and derived classes that inherit this implements it's properties or methods.

Static, Value Types & interface doesn't support abstract modifiers. Static members cannot be abstract. Classes with abstract member must also be abstract.

11) What is an Interface?

An interface is a contract & defines the requisite behavior of generalization of types.

Interface is an outside view of a class or object which emphaizes its abstraction while hiding its structure and secrets of its behaviour.
An interface mandates a set of behavior, but not the implementation. Interface must be inherited. We can't create an instance of an interface.
An interface is an array of related function that must be implemented in derived type. Members of an interface are implicitly public & abstract. An interface can inherit from another interface.

12) What is a base class?

Base class is the most generalised class in a class structure. Most applications have such root classes. In Java, Object is the base class for all classes.

13) What is a subclass?

Subclass is a class that inherits from one or more classes.

14) What is a superclass?

superclass is a class from which another class inherits.

15) What is a constructor?

Constructor is an operation that creates an object and/or initialises its state.

16) What is a destructor?

Destructor is an operation that frees the state of an object and/or destroys the object itself.

17) What is meant by Binding?

Binding denotes association of a name with a class.

18) What is meant by static binding?

Static binding is a binding in which the class association is made during compile time. This is also called as Early binding.

19) What is meant by Dynamic binding?

Dynamic binding is a binding in which the class association is not made until the object is created at execution time. It is also called as Late binding.

20) Define Modularity?

Modularity is the property of a system that has been decomposed into a set of cohesive and loosely coupled modules.

21) What is meant by Persistence?

Persistence is the property of an object by which its existence transcends space and time.

22) How to prevent a class from being inherited?

In order to prevent a class in C# from being inherited, the keyword sealed is used. Thus a sealed class may not serve as a base class of any other class. It is also obvious that a sealed class cannot be an abstract class.
//C# Example
sealed class MyClass
{
public int x;
public int y;
}
No class can inherit from MyClass defined above. Instances of ClassA may be created and its members may then be accessed.

23) What is Polymorphism?

Polymorphism means one interface and many forms. Polymorphism is a characteristics of being able to assign a different meaning or usage to something in different contexts specifically to allow an entity such as a variable, a function or an object to have more than one form.

There are two types of Polymorphism.

Compile time: function or operator overloading
Runtime: Inheritence & virtual functions

24) What is Abstract method?

Abstract method doesn't provide the implementation & forces the derived class to override the method.

25) What is Virtual method?

Virtual Method allows a derived class with the option to override it.

25) Can Struct be inherited?

No, Struct can't be inherited as this is implicitly sealed.

26) What is Static field?

To indicate that a field should only be stored once no matter how many instance of the class we create.

27) What is Static Method?

It is possible to declare a method as Static provided that they don't attempt to access any instance data or other instance methods.

28) What is Virtual keyword?

This keyword indicates that a member can be overridden in a child class. It can be applied to methods, properties, indexes and events.

29) What is New modifiers?

The new modifiers hides a member of the base class. C# supports only hide by signature.

30) What is Sealed modifiers?

Sealed types cannot be inherited & are concrete.
Sealed modifiers can also be applied to instance methods, properties, events & indexes. It can't be applied to static members.
Sealed members are allowed in sealed and non-sealed classes.

31) When to use Interface over abstract class?

Abstract Classes: Classes which cannot be instantiated. This means one cannot make a object of this class or in other way cannot create object by saying
ClassAbs abs = new ClassAbs(); where ClassAbs is abstract class.
Abstract classes contains one or more abstarct methods, ie method body only no implementation.
Interfaces: These are same as abstract classes only difference is that we can only define method definition and no implementation.
When to use what depends on various reasons. One being design choice.
One reason for using abstarct classes is we can code common functionality and force our developer to use it. I can have a complete class but I can still mark the class as abstract.
Developing by interface helps in object based communication.

32) What is pure virtual function?

When you define only function prototype in a base class without and do the complete implementation in derived class. This base class is called abstract class and client won’t able to instantiate an object using this base class.

A pure virtual function is a function that must be overridden in a derived class and need not be defined. A virtual function is declared to be "pure" using the curious "=0"
syntax:
class Base {
public:
void f1(); // not virtual
virtual void f2(); // virtual, not pure
virtual void f3() = 0; // pure virtual
};

33) Can we specify the access modifier for explicitly implemented interface method?

No, we can't specify the access modifier for the explicitly implemented interface method. By default its scope will be internal.

34) What is Protected access modifier in C#?

The protected keyword is a member access modifier. It can only be used in a declaring a function or method not in the class ie. a class can't be declared as protected class.

A protected member is accessible from within the class in which it is declared, and from within any class derived from the class that declare this member. In other words access is limited to within the class definition and any class that inherits from the class

A protected member of a base class is accessible in a derived class only if the access takes place through the derived class type.

35) What is Public access modifier in C#?

The public keyword is an access modifier for types and type members ie. we can declare a class or its member (functions or methods) as Public. There are no restrictions on accessing public members.

36) What is Private access modifier in C#?

The private keyword is a member access modifier ie. we can't explicitly declare a class as Private, however if do not specify any access modifier to the class, its scope will be assumed as Private. Private access is the least permissive access level of all access modifiers.

Private members are accessible only within the body of the class or the struct in which they are declared. This is the default access modifier for the class declaration.

37) What is Internal access modifier in C#?

The internal keyword is an access modifier for types and type members ie. we can declare a class as internal or its member as internal. Internal members are accessible only within files in the same assembly (.dll). In other words, access is limited exclusively to classes defined within the current project assembly.

38 ) What is Protected Internal access modifier in C#?

Protected Internal is a access modifiers for the members (methods or functions) ie. you can't declare a class as protected internal explicitly. The members access is limited to the current assembly or types derived from the containing class.

Protected Internal means the method is accessible by anything that can access the protected method UNION with anything that can access the internal method.

39) What all classes bear Default Access modifiers in C#?

a) An enum has default modifier as public

b) A class has default modifiers as Internal .
It can declare members (methods etc) with following access modifiers:
public
internal
private
protected internal

c) An interface has default modifier as public

d) A struct has default modifier as Internal .
It can declare its members (methods etc) with following access modifiers:
public
internal
private

e) A methods, fields, and properties has default access modifier as "Private" if no modifier is specified.

40) What is method overloading?

Method overloading occurs when a class contains two methods with the same name, but different signatures.Method overloading allows us to write different version of the same method in a class or derived class. Compiler automatically select the most appropriate method based on the parameter supplied.

Example:

public class AddClass

{

public int Add(int a, int b)

{

return a + b;

}

public int Add(int a, int b, int c)

{

return a+b+c;

}

}
To call the above method, you can use following code.

AddClass ad= new AddClass();

int number = ad.Add(2, 3) // result =5

int number1 = ad.Add(2, 3, 4) // result = 9

Rules for Overloading
There must be changes in either return type,or number of parameters or type of parameters.
You can't have a overload method with same number parameters but different return type. In order to create overload method, the return type must be the same and parameter type must be different or different in numbers.

41) What is Overriding?

Method overriding is a feature that allows to invoke functions (that have the same signatures) and that belong to different classes in the same hierarchy of inheritance using the base class reference. In C# it is done using keywords virtual and override .

42) What is Method Overriding? How to override a function in C#?

Use the override modifier to modify a method, a property, an indexer, or an event. An override method provides a new implementation of a member inherited from a base class. The method overridden by an override declaration is known as the overridden base method. The overridden base method must have the same signature as the override method.
You cannot override a non-virtual or static method. The overridden base method must be virtual, abstract, or override.

43) Can we call a base class method without creating instance?

Yes. But ..

* Its possible If its a static method.

* Its possible by inheriting from that class also.

* Its possible from derived classes using base keyword.

44) In which cases you use override and new base?

Use the new modifier to explicitly hide a member inherited from a base class. To hide an inherited member, declare it in the derived class using the same name, and modify it with the new modifier.

45) Difference between new and override keyword?

Consider the following program.

using System;

class Program
{
public class BaseClass
{

public virtual void func1()
{

Console.WriteLine("Base Class function 1.");

}

public virtual void func2()
{

Console.WriteLine("Base Class function 2.");

}

public void func3()
{

Console.WriteLine("Base Class function 3.");

}

}

public class DeriveClass : BaseClass
{

public new void func1()
{

Console.WriteLine("Derieve Class fuction 1 used new keyword");

}

public override void func2()
{

Console.WriteLine("Derieve Class fuction 2 used override keyword");

}

public void func3()
{

Console.WriteLine("Derieve Class fuction 3 used override keyword");

}

}

static void Main(string[] args)
{
BaseClass b = new BaseClass();

b.func1();

DeriveClass d = new DeriveClass();

d.func1();

//Calls Base class function 1 as new keyword is used.

BaseClass bd = new DeriveClass();

bd.func1();

//Calls Derived class function 2 as override keyword is used.

BaseClass bd2 = new DeriveClass();

bd2.func2();

Console.Read();

}
}

Now the difference is

new: hides the base class function.
Override: overrides the base class function.

BaseClass objB = new DeriveClass();

If we create object like above notation and make a call to any function which exists in base class and derive class both, then it will always make a call to function of base class. If we have overidden the method in derive class then it wlll call the derive class function.

For example…

objB.func1(); //Calls the base class function. (In case of new keyword)

objB.func2(); //Calls the derive class function. (Override)

objB.func3(); //Calls the base class function.(Same prototype in both the class.)

Note:
// This will throw a compile time error. (Casting is required.)

DeriveClass objB = new BaseClass();

//This will throw run time error. (Unable to cast)

DeriveClass objB = (DeriveClass) new BaseClass();

Exploring Drives,directories and Files

2013-03-25T22:31:00.000-07:00

learning c# programming Exploring Drives,directories and Files

Exploring Drives,directories and Files

Create a windows form in C#, with a combo box, treeview, listbox and a picture box.

private void exploreEg_Load(object sender, EventArgs e)
{
foreach (DriveInfo d in DriveInfo.GetDrives())
comboBox1.Items.Add(d.Name);
}

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
DriveInfo dr = new DriveInfo(comboBox1.SelectedItem.ToString());
if (dr.IsReady)
{
treeView1.Nodes.Clear();
DirectoryInfo di = new DirectoryInfo(dr.Name);
listBox1.Items.Clear();
foreach (FileInfo fi in di.GetFiles())
{
if (fi.Extension.ToUpper().Trim() == ".JPG")
listBox1.Items.Add(fi.FullName);
}
foreach (DirectoryInfo d in di.GetDirectories())
{
treeView1.Nodes.Add(d.FullName);
}
}
else
MessageBox.Show("Drive is not ready");
}

private void treeView1_AfterSelect(object sender, TreeViewEventArgs e)
{
DirectoryInfo di = new DirectoryInfo(treeView1.SelectedNode.Text);
if (di.Exists)
{
listBox1.Items.Clear();
foreach (DirectoryInfo d in di.GetDirectories())
{
treeView1.SelectedNode.Nodes.Add(d.FullName);
}
foreach (FileInfo fi in di.GetFiles())
{
if (fi.Extension.ToUpper().Trim() == ".JPG")
listBox1.Items.Add(fi.FullName);
}
}
}

private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
{
FileInfo fi = new FileInfo(listBox1.SelectedItem.ToString());
label1.Text ="Created Time "+ fi.CreationTime.ToString();
label2.Text ="Directory "+ fi.DirectoryName;
label3.Text = "Extension "+fi.Extension;
pictureBox1.Image = Image.FromFile(listBox1.SelectedItem.ToString());
}

Happy Programming !!!!!!!!!!!!!!!!

Object Oriented Programming Concepts (OOPS) in C#.net

2013-03-25T22:14:00.002-07:00

c# training online Introduction to Object Oriented Programming Concepts (OOPS) in C#.net Introduction to Object Oriented Programming Concepts (OOPS) in C#.net

Class:

It is a collection of objects. or we can say class describes , what an object is.

Object:

It is a real time entity. That is a real world existance of any substance can be called as an object. An object can be considered a "thing" that can perform a set of related activities. The set of activities that the object performs defines the object's behavior.

For example, a Student (object) can give the name or address. In pure OOP terms an object is an instance of a class.

Class is composed of three things name, attributes, and operations

public class student

{

}

student blessy=new student ();

According to the above sample we can say that Student object, named blessy , has created as an object of student class.

Encapsulation:

Encapsulation is a process of binding the data members and member functions into a single unit.

Example for encapsulation is class. A class can contain data structures and methods.

Consider the following class

public class Triangle

{

public Triangle()

{

}

protected double height;

protected double width;

public double getarea()

{

Double area=height * width ;

if (area<0)

return 0;

return area;

}

}
In this example we encapsulate some data such as height, width and method getarea. Other methods or objects can interact with this object through methods that have public access modifier

Abstraction:

Abstraction is a process of hiding the implementation details and displaying the essential features.

Example1: A Laptop consists of many things such as processor, motherboard, RAM, keyboard, LCD screen, wireless antenna, web camera, usb ports, battery, speakers etc. To use it, you don't need to know how internally LCD screens, keyboard, web camera, battery, wireless antenna, speaker’s works. You just need to know how to operate the laptop by switching it on. Think about if you would have to call to the engineer who knows all internal details of the laptop before operating it. This would have highly expensive as well as not easy to use everywhere by everyone.

So here the Laptop is an object that is designed to hide its complexity.

How to abstract: - By using Access Specifiers

.Net has five access Specifiers

Public -- Accessible outside the class through object reference.
Private -- Accessible inside the class only through member functions.
Protected -- Just like private but Accessible in derived classes also through member functions.
Internal -- Visible inside the assembly. Accessible through objects.
Protected Internal -- Visible inside the assembly through objects and in derived classes outside the assembly through member functions.

Example:-

public class Class1

{

int i; //No Access specifier means private

public int j; // Public

protected int k; //Protected data

internal int m; // Internal means visible inside assembly

protected internal int n; //inside assembly as well as to derived classes outside
//assembly

static int x; // This is also private

public static int y; //Static means shared across objects

[DllImport("MyDll.dll")]

public static extern int MyFoo(); //extern means declared in this assembly defined in
//some other assembly

public void myFun2()

{

//Within a class if you create an object of same class then you can access all data members through object reference even private data too

Class1 obj = new Class1();

obj.i =10; //Error can’t access private data through object.But here it is accessible.:)

obj.j =10;

obj.k=10;

obj.m=10;

obj.n=10;

// obj.s =10; //Errror Static data can be accessed by class names only

Class1.x = 10;

// obj.y = 10; //Errror Static data can be accessed by class names only

Class1.y = 10;

}

[STAThread]

static void Main()

{

//Access specifiers comes into picture only when you create object of class outside the class

Class1 obj = new Class1();

// obj.i =10; //Error can’t access private data through object.

obj.j =10;

// obj.k=10; //Error can’t access protected data through object.

obj.m=10;

obj.n=10;

// obj.s =10; //Errror Static data can be accessed by class names only

Class1.x = 10; //Error can’t access private data outside class

// obj.y = 10; //Errror Static data can be accessed by class names only

Class1.y = 10;

}

In object-oriented software, complexity is managed by using abstraction.

Abstraction is a process that involves identifying the critical behavior of an object and eliminating irrelevant and complex details.

Inheritance:

Inheritance is a process of deriving the new class from already existing class

C# is a complete object oriented programming language. Inheritance is one of the primary concepts of object-oriented programming. It allows you to reuse existing code. Through effective use of inheritance, you can save lot of time in your programming and also reduce errors, which in turn will increase the quality of work and productivity. A simple example to understand inheritance in C#.

Using System;

Public class BaseClass

{

Public BaseClass ()

{

Console.WriteLine ("Base Class Constructor executed");

}

Public void Write ()

{

Console.WriteLine ("Write method in Base Class executed");

}

Public class ChildClass: BaseClass

{

Public ChildClass ()

{

Console.WriteLine("Child Class Constructor executed");

}

Public static void Main ()

{

ChildClass CC = new ChildClass ();

CC.Write ();

}

In the Main () method in ChildClass we create an instance of childclass. Then we call the write () method. If you observe the ChildClass does not have a write() method in it. This write () method has been inherited from the parent BaseClass.
The output of the above program is

Output:
Base Class Constructor executed
Child Class Constructor executed
Write method in Base Class executed

this output proves that when we create an instance of a child class, the base class constructor will automatically be called before the child class constructor. So in general Base classes are automatically instantiated before derived classes.
In C# the syntax for specifying BaseClass and ChildClass relationship is shown below. The base class is specified by adding a colon, ":", after the derived class identifier and then specifying the base class name.

Syntax: class ChildClassName: BaseClass
{
//Body
}

C# supports single class inheritance only. What this means is, your class can inherit from only one base class at a time. In the code snippet below, class C is trying to inherit from Class A and B at the same time. This is not allowed in C#. This will lead to a compile time error: Class 'C' cannot have multiple base classes: 'A' and 'B'.

public class A

{

}

public class B

{

}

public class C : A, B

{

}

In C# Multi-Level inheritance is possible. Code snippet below demonstrates mlti-level inheritance. Class B is derived from Class A. Class C is derived from Class B. So class C, will have access to all members present in both Class A and Class B. As a result of multi-level inheritance Class has access to A_Method(),B_Method() and C_Method().

Note: Classes can inherit from multiple interfaces at the same time.

Using System;

Public class A

{

Public void A_Method ()

{

Console.WriteLine ("Class A Method Called");

}

Public class B: A

{

Public void B_Method ()

{

Console.WriteLine ("Class A Method Called");

}

Public class C: B

{

Public void C_Method ()

{

Console.WriteLine ("Class A Method Called");

}

Public static void Main ()

{

C C1 = new C ();

C1.A_Method ();

C1.B_Method ();

C1.C_Method ();

}

When you derive a class from a base class, the derived class will inherit all members of the base class except constructors. In the code snippet below class B will inherit both M1 and M2 from Class A, but you cannot access M2 because of the private access modifier. Class members declared with a private access modifier can be accessed only with in the class. We will talk about access modifiers in our later article.

Are private class members inherited to the derived class?

Yes, the private members are also inherited in the derived class but we will not be able to access them. Trying to access a private base class member in the derived class will report a compile time error.

Using System;

Public class A

{

Public void M1 ()

{

}

Private void M2 ()

{

}

Public class B: A

{

Public static void Main ()

{

B B1 = new B ();

B1.M1 ();

//Error, Cannot access private member M2

//B1.M2 ();

}

Method Hiding and Inheritance We will look at an example of how to hide a method in C#. The Parent class has a write () method which is available to the child class. In the child class I have created a new write () method. So, now if I create an instance of child class and call the write () method, the child class write () method will be called. The child class is hiding the base class write () method. This is called method hiding.

If we want to call the parent class write () method, we would have to type cast the child object to Parent type and then call the write () method as shown in the code snippet below.

Using System;

Public class Parent

{

Public void Write ()

{

Console.WriteLine ("Parent Class write method");

}

Public class Child: Parent

{

Public new void Write ()

{

Console.WriteLine ("Child Class write method");

}

Public static void Main ()

{

Child C1 = new Child ();

C1.Write ();

//Type caste C1 to be of type Parent and call Write () method

((Parent) C1).Write ();

}

Polymorphism:

When a message can be processed in different ways is called polymorphism. Polymorphism means many forms.

Polymorphism is one of the fundamental concepts of OOP.

Polymorphism provides following features:

It allows you to invoke methods of derived class through base class reference during runtime.
It has the ability for classes to provide different implementations of methods that are called through the same name.

Polymorphism is of two types:

Compile time polymorphism/Overloading
Runtime polymorphism/Overriding

Compile Time Polymorphism

Compile time polymorphism is method and operators overloading. It is also called early binding.

In method overloading method performs the different task at the different input parameters.

Runtime Time Polymorphism

Runtime time polymorphism is done using inheritance and virtual functions. Method overriding is called runtime polymorphism. It is also called late binding.

When overriding a method, you change the behavior of the method for the derived class. Overloading a method simply involves having another method with the same prototype.

Caution: Don't confused method overloading with method overriding, they are different, unrelated concepts. But they sound similar.

Method overloading has nothing to do with inheritance or virtual methods.

Following are examples of methods having different overloads:

void area(int side);

void area(int l, int b);

void area(float radius);

Practical example of Method Overloading (Compile Time Polymorphism)

using System;

namespace method_overloading

{

class Program

{

public class Print

{

public void display(string name)

{

Console.WriteLine ("Your name is : " + name);

}

public void display(int age, float marks)

{

Console.WriteLine ("Your age is : " + age);

Console.WriteLine ("Your marks are :" + marks);

}

static void Main(string[] args)

{

Print obj = new Print ();

obj.display ("Blessy");

obj.display (34, 76.50f);

Console.ReadLine ();

}

Note: In the code if you observe display method is called two times. Display method will work according to the number of parameters and type of parameters.

When and why to use method overloading

Use method overloading in situation where you want a class to be able to do something, but there is more than one possibility for what information is supplied to the method that carries out the task.

You should consider overloading a method when you for some reason need a couple of methods that take different parameters, but conceptually do the same thing.

Method overloading showing many forms.

using System;

namespace method_overloading_polymorphism

{

Class Program

{

Public class Shape

{

Public void Area (float r)

{

float a = (float)3.14 * r;

// here we have used function overload with 1 parameter.

Console.WriteLine ("Area of a circle: {0}",a);

}

Public void Area(float l, float b)

{

float x = (float)l* b;

// here we have used function overload with 2 parameters.

Console.WriteLine ("Area of a rectangle: {0}",x);

}

public void Area(float a, float b, float c)

{

float s = (float)(a*b*c)/2;

// here we have used function overload with 3 parameters.

Console.WriteLine ("Area of a circle: {0}", s);

}

Static void Main (string[] args)

{

Shape ob = new Shape ();

ob.Area(2.0f);

ob.Area(20.0f,30.0f);

ob.Area(2.0f,3.0f,4.0f);

Console.ReadLine ();

}

Things to keep in mind while method overloading

If you use overload for method, there are couple of restrictions that the compiler imposes.

The rule is that overloads must be different in their signature, which means the name and the number and type of parameters.

There is no limit to how many overload of a method you can have. You simply declare them in a class, just as if they were different methods that happened to have the same name.

Creating and Reading xml in C#

2013-03-25T04:14:00.002-07:00

xml in c# Creating xml in C#

.Net provides 2 ways for creating xml thru. code

1. using XMLTextWriter

2.using DataSet

XMLTextWriter class

here is an example of creating xml using xmltextwriter class

import the following namespaces

using System.Diagnostics;
using System.Xml;
XmlTextWriter xtw;

On the code behind of Button Click , write the following code

xtw = new XmlTextWriter("d:\\Contacts.xml",null);
xtw.WriteStartElement("Contacts");
xtw.WriteStartElement("Contact");
xtw.WriteStartElement("Name");
xtw.WriteString("Shalini");
xtw.WriteEndElement();
xtw.WriteStartElement("Location");
xtw.WriteString("Kochi");
xtw.WriteEndElement();
xtw.Close();
Process.Start("d:\\Contacts.xml", "iexplore");

DataSet class

We can create xml files using DataSet class

import the following namespaces
using System.Diagnostics;
using System.Xml;
using System.Data.SqlClient;
On the code behind of Button Click , write the following code

DataSet ds=new DataSet();

SqlConnection con=new SqlConnection(constring);
SqlDataAdapter ad=new SqlDataAdapter("Select * from student",con);
ad.Fill(ds,"stud");
ds.WriteXml("d:\\a.xml");

Process.Start("Notepad","d:\\a.xml");

Reading xml data using XMLTextReader
--------------------------------------------

here is an xml file

<names>
<faculty>Blessy</faculty>
<blog>BlessyS.blogspot.com</blog>
<faculty>Blety</faculty>
<blog>Blety.blogspot.com</blog>
</names>

to read from this file

XmlTextReader xmlr = new XmlTextReader(@"d:\blessy\xmleg\xmleg\XMLFile2.xml");

private void buttonshow_Click(object sender, EventArgs e)
{
while (xmlr.Read())
{
switch (xmlr.Name)
{
case "faculty":
MessageBox.Show(xmlr.ReadString());
break;

case "blogs":
MessageBox.Show(xmlr.ReadString());
break;

}
}
}

Select Elements with jQuery

2013-03-25T04:03:00.002-07:00

jQuery online training Different Select methods in jQuery

The easiest way to target a specific element or a set of elements within a document is by using a CSS selector within the jQuery wrapper function, like so:
jQuery('#content p a');
// Select all anchor elements within all paragraph elements within #content

Now that we’ve selected the elements we’re after, we can run any of jQuery’s methods on that collection. For example, adding a class of selected to all links is as simple as:

jQuery('#content p a').addClass('selected');

jQuery offers many DOM traversal methods to aid in the element selection process, such as next(), prev(), and parent(). These and other methods accept a selector expression as their only parameter, which filters the returned results accordingly. So, you can use CSS selectors in a number of places, not just within jQuery(...).When constructing selectors, there’s one general rule for optimization: be only as specific
as you need to be. It’s important to remember that the more complicated a selector is, the more time it will take jQuery to process the string. jQuery uses native DOM methods to retrieve the elements you’re after.

Here is an example of an unnecessarily complicated selector:

jQuery('body div#wrapper div#content');

A higher degree of specificity does not necessarily mean it’s faster.

The previous selector can be rewritten to this:
jQuery('#content');

Select Child elements

Use the direct descendant combinator (>). This combinator expects two selector expressions,one on either side. For example, if you want to select all anchor elements that reside directly beneath list items, you could use this selector: li > a. This would select all anchors that are children of a list item; in other words, all anchors that exist directly beneath list items.

Here’s an example:

<a href="/category">Category</a>
<ul id="nav">
<li><a href="#anchor1">Anchor 1</a></li>
<li><a href="#anchor2">Anchor 2</a></li>
<li><span><a href="#anchor3">Anchor 3</a></span></li>
</ul>
to select only the anchors within each list item, you would call jQuery like so:

jQuery('#nav li > a');

// This selects two elements, as expected

The third anchor within the #nav list is not selected because it’s not a child of a list item;
it’s a child of a <span> element.

Selecting Specific Siblings

Consider the following example HTML markup:

<div id="content">
<h1>Main title</h1>
<h2>Section title</h2>
<p>Some content...</p>
<h2>Section title</h2>
<p>More content...</p>
</div>

If you want to select only <h2> elements that immediately follow <h1> elements,
you can use the following selector:

jQuery('h1 + h2');
// Selects ALL H2 elements that are adjacent siblings of H1 elements

Selecting Elements by Index Order

Assuming the following HTML markup:
<ol>
<li>First item</li>
<li>Second item</li>
<li>Third item</li>
<li>Fourth item</li>
</ol>
the first item in the list could be selected in a number of different ways:

jQuery('ol li:first');
jQuery('ol li:eq(0)');
jQuery('ol li:lt(1)');

Notice that both the eq() and lt() filters accept a number; since it’s zero-indexed, the
first item is 0, the second is 1, etc.
A common requirement is to have alternating styles on table rows; this can be achieved
with the :even and :odd filters:

Example

<table>
<tr><td>0</td><td>even</td></tr>
<tr><td>1</td><td>odd</td></tr>
<tr><td>2</td><td>even</td></tr>
<tr><td>3</td><td>odd</td></tr>
<tr><td>4</td><td>even</td></tr>
</table>

You can apply a different class dependent on the index of each table row:

jQuery('tr:even').addClass('even');

You’d have to specify the corresponding class (even) in your CSS style sheet:

table tr.even {
background: #CCC;
}

How to Include the jQuery Library Code in an HTML Page

2013-03-25T03:46:00.003-07:00

jQuery online training Include jQuery Library Code in an HTML Page Include jQuery Library Code in an HTML Page

jQuery is a fast, small, and feature-rich JavaScript library. It makes things like HTML document traversal and manipulation, event handling, animation, and Ajax much simpler with an easy-to-use API that works across a multitude of browsers. With a combination of versatility and extensibility, jQuery has changed the way that millions of people write JavaScript.

There are currently two ideal solutions for embedding the jQuery library in a web page:

• Use the Google-hosted content delivery network (CDN) to include a version of

jQuery (used in this chapter).

• Download your own version of jQuery from jQuery.com and host it on your own

server or local filesystem.

the following is a template that includes the jQuery library that you can use to start any jQuery project:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"

"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html>

<head>

<script type="text/JavaScript"

src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>

</head>

<body>

alert('jQuery ' + jQuery.fn.jquery);

</script>

</body>

</html>

However, debugging JavaScript errors in minified code is not ideal. During code development, or on the production site, it actually ight be better to use the nonminified version from Google for the purpose of debugging potential JavaScript errors. For more information about using the Googlehosted version of jQuery, you can visit the Ajax libraries API site on the Web at http://

code.google.com/apis/ajaxlibs/.

Simple JQuery Examples

2013-03-25T00:33:00.000-07:00

jQuery online training with examples

Simple JQuery Examples

Hello World Example

<html>
<head>
<title>jQuery Hello World</title>

<script type="text/javascript" src="jquery-1.4.2.js"></script>

</head>

<script type="text/javascript">

$(document).ready(function(){
$("#flag").html("Hello World !! (display due to jQuery)");
});

</script>
<body>
<font color=red>
Hello World !! (display due to HTML)
</font>
<font color=blue>
<div id="flag">
</div>
</font>
</body>
</html>

Hello world alert box example

<html>

<head>

<title>jQuery Hello World Alert box</title>

</head>

$(document).ready(function(){

$("#cl").click(function(){

alert("HELLO WORLD!");

});

</script>

<body>

<font color="red">CLICK BELOW BUTTON TO SEE ALERT BOX</font>

<br>

<button id="cl">Click Me</button>

</body>

</html>

Preloading Images Using jQuery

It is always a good practice to preload images, because is speeds up the rendering of Web pages. The following piece of code preloads images using jQuery:

jQuery.preloadImages = function()

{

for(var x = 0; x").attr("src", arguments[x]);

}};

Disabling the Context Menu Using jQuery

The following code snippet illustrates how you can disable the context menu in jQuery:

$(document).ready(function(){

$(document).bind("contextmenu",function(e){

return false;

});

Adding and Removing CSS Class in jQuery

It is easy to add and remove CSS classes in jQuery.

//To add a css class, you can use the following piece of code

if($(id).hasClass('testClass'))

{

$('#div1').addClass('testclass');

}

//To remove a css class, you can use the following piece of code

if($(id).hasClass('testClass'))

{

$('#div1').removeClass('testclass');

}

Checking If a Particular Element Is Available

You can easily check whether an element exists in a Web page using jQuery. Here is an example:

if ($('img').length)

{

alert('Image elements available');

}

else

{

alert('Image elements not available');

}

Detect Browser Type Using jQuery

Different browsers execute scripts differently, but you can easily detect browser type in jQuery and then execute your custom code accordingly. Here is how you can detect browser type:

if (jQuery.browser.mozilla)

{

// Code to execute if browser is Mozilla

}

if (jQuery.browser.msie)

{

// Code to execute if browser is IE

}

if (jQuery.browser.safari)

{

// Code to execute if browser is Safari

}

if (jQuery.browser.opera)

{

// Code to execute if browser is Opera

}

Find Hidden Elements Using jQuery

You can use the Size() method to determine whether any DOM elements are hidden. Here is an example:

if( $("div.hidden").size)

{

alert('One or more divs are hidden');

}

You can achieve the same result using the length() function as well. Note that the Size() function uses the Length() function internally. Hence, it works faster.

if( $("div.hidden").length )

{

alert('One or more divs are hidden');

}

Retrieve the Parent Element of an Element

It is easy to retrieve the parent element of an element in jQuery. All you have to do is use the closest() method as shown below:

var id = $("btnHello").closest("div").attr("id");

Use Chaining in jQuery Properly

Chaining is a great jQuery feature. It facilitates a list of actions that are executed one after the other. You can use it to chain methods, as shown in the code snippet below:

$('div1').removeClass('color').addClass('no-color');

Manipulating Select List with jQuery

JQuery makes working with a Select List easy. You can easily remove an option from a Select List. Here's how:

$("#employeeList option[value='9']").remove();

Retrieve the selected option from a Select List as text

The following code snippet illustrates how you can retrieve the selected option from a Select List as text:

$('#employeeList :selected').text();

use jQuery to change the background color of ASP.NET TextBox controls to yellow when they have focus.

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ShowjQuery.aspx.cs" Inherits="ShowjQuery" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head runat="server">

    <title>Show jQuery</title>

</head>

<body>

    <form id="form1" runat="server">

    <div>

        <asp:TextBox ID="txtFirstName" runat="server" />

        <br />

        <asp:TextBox ID="txtLastName" runat="server" />

    </div>

    </form>

    <script src="Scripts/jquery-1.4.1.js" type="text/javascript"></script>

    <script type="text/javascript">

        $("input").focus( function() { $(this).css("background-color", "yellow"); });

    </script>

</body>

</html>

JQUERRY Introduction

2013-03-25T00:22:00.001-07:00

Learn jQuery Online

jQuery

jQuery is JavaScript Library which aids developer to play with JavaScript quickly. There are many features covered in the library which are tested on IE 6.0+, FF 2+, Safari 3.0+, Opera 9.0+, Chrome. It has around 19KB of footprint.

In JavaScript, we are using document.getElementById to get the element which we want. And then we operate upon it. The same functionality is used by $. But if getElementById is DROP then $ is full RIVER.

There are many parts of learning jQuery

1. Selectors: Help you to select the element(s) from the page. It could be one element or array of elements

$( expression, context ) will be used to select element(s). There are many type of expression supported by jQuery to easily select what we want. expression will be string with quotes.

Following are the type of selection we can make with the jQuery

Basic Selectors

Suppose you want to select all the div present in the page, you will write $(“div”), same way for td, its $(“td”)
If you want element with some ID, remember the CSS stuff. In CSS when you make class with # sign, it will apply to element contain that ID. Concept is similar here. jQuery uses CSS selector the same way. So you can write $(“#Manish”) and it will return element with id=”Manish”.

· Same way, remember CSS for class. You put . (dot) before class and apply that class to any element to enable the style written in class. Here if you want to find elements which has some class value, you must use .(dot) before that. Suppose you wanted to find elements with “red” class style throughout page, use $(“.red”).

· You can mix two or more selector and make your own selector. So you can write like

$(“div ,p, span”) and it will return array of all div+p+span tag elements. You can also specify the id/class with the tag. e.g. $(“p.manish”). It will return all <p> tag with “manish” class.

Index Filters

With index filters, you can select the tags with specified index or indexing function. And index filter will be specified by : (Colon) sign. Actually all the filters will be specified by : (Colon)

If you need to select first element from the array for certain tag, you can query like $(“tr:first”). This will return first <tr> from the page. Same way $(“tr:last”), $(“tr:even”), $(“tr:odd”) work.
There are some function index also, which provides array of elements for criteria known as eq,lt,gt. For example $(“tr:eq(2)”) gives second tr from the page. $(“tr:lt(4)”) provides tr less than 4

Content Filters

With this filter you can query page using content in query. There are four type of content selector. :Contains(text), :empty, :has(selector), :parent. example of each is in order.. $(“div:contains(‘Manish’)”), $(“div:empty”), $(“div:has(p)”, $(“div:parent”) returns all div contains manish, all div which are empty, all div which has p tag, and last all div which are parents, accordingly.

Visibility Filters

Simplest filters of all. Filters are $(“div:hidden”) and $(“div:visible”)

Attribute Filters

With attribute filters, you can query html page with the tags with provided attribute criteria. Attribute criteria is provided in [ ] (Square brackets). Please note that in function filters or in attribute filters, you are using “ (Quotes) anywhere. You can query for input tag which has text attribute equal to Manish. At some places, you can see @ sign for attribute but it is deprecated from version 1.2 and removed from 1.3.

$(“div[id]”) returns all div on the page with id attribute.
$(“div[id=’Manish’]”) returns div with id=Manish. Here you need to provide quotes. same way $(“div[id!=’Manish’]”)
There are 3 more attribute filter which has blood relation with regular expression. If you are aware of ^, $ and * sign, it would be easy to understand. If i write ^Manish, then it will return all the words started with Manish. If I write $Manish, it will return words end with Manish. and * is for contains. That means *Manish can find words which cotains Manish, no matter at which position. Same funda will be used in $(“input[name^=’btn’]”), $(“input[name$=’btn’]”),$(“input[name*=’btn’]”)

Generally selectors are used to select elements from the page and then manipulate the appearance of that element. For example, $(“p”).css(“color”,”red”) when executed, change the color of all paragraph to red!!!

HTML Tags Chart

2013-03-25T00:01:00.001-07:00

Create a webpage html tags chart

HTML Tags Chart

Tag	Name	Code Example
<!--	comment	<!--This can be viewed in the HTML part of a document-->
<a -	anchor	<a href="http://www.domain.com/"> Visit Our Site</a>
<b>	bold	<b>Example</b>
<big>	big (text)	<big>Example</big>
<body>	body of HTML document	<body>The content of your HTML page</body>
<br>	line break	The contents of your page<br>The contents of your page
<center>	center	<center>This will center your contents</center>
<dd>	definition description	<dl> <dt>Definition Term</dt> <dd>Definition of the term</dd> <dt>Definition Term</dt> <dd>Definition of the term</dd> </dl>
<dl>	definition list	<dl> <dt>Definition Term</dt> <dd>Definition of the term</dd> <dt>Definition Term</dt> <dd>Definition of the term</dd> </dl>
<dt>	definition term	<dl> <dt>Definition Term</dt> <dd>Definition of the term</dd> <dt>Definition Term</dt> <dd>Definition of the term</dd> </dl>
<em>	emphasis	This is an <em>Example</em> of using the emphasis tag
<embed>	embed object	<embed src="yourfile.mid" width="100%" height="60" align="center">
<embed>	embed object	<embed src="yourfile.mid" autostart="true" hidden="false" loop="false"> <noembed><bgsound src="yourfile.mid" loop="1"></noembed>
<font>	font	<font face="Times New Roman">Example</font>
<font>	font	<font face="Times New Roman" size="4">Example</font>
<font>	font	<font face="Times New Roman" size="+3" color="#ff0000">Example</font>
<form>	form	<form action="mailto:you@yourdomain.com"> Name: <input name="Name" value="" size="10"><br> Email: <input name="Email" value="" size="10"><br> <center><input type="submit"></center> </form>
<h1> <h2> <h3> <h4> <h5> <h6>	heading 1 heading 2 heading 3 heading 4 heading 5 heading 6	<h1>Heading 1 Example</h1> <h2>Heading 2 Example</h2> <h3>Heading 3 Example</h3> <h4>Heading 4 Example</h4> <h5>Heading 5 Example</h5> <h6>Heading 6 Example</h6>
<head>	heading of HTML document	<head>Contains elements describing the document</head>
<hr>	horizontal rule	<hr />
<hr>	horizontal rule	<hr width="50%" size="3" />
<hr>	horizontal rule	<hr width="50%" size="3" noshade />
<hr> (Internet Explorer)	horizontal rule	<hr width="75%" color="#ff0000" size="4" />
<hr> (Internet Explorer)	horizontal rule	<hr width="25%" color="#6699ff" size="6" />
<html>	hypertext markup language	<html> <head> <meta> <title>Title of your web page</title> </head> <body>HTML web page contents </body> </html>
<i>	italic	<i>Example</i>
<img>	image	<img src="Earth.gif" width="41" height="41" border="0" alt="text describing the image" />
<input>	input field	Example 1: <form method=post action="/cgi-bin/example.cgi"> <input type="text" size="10" maxlength="30"> <input type="Submit" value="Submit"> </form>
<input> (Internet Explorer)	input field	Example 2: <form method=post action="/cgi-bin/example.cgi"> <input type="text" style="color: #ffffff; font-family: Verdana; font-weight: bold; font-size: 12px; background-color: #72a4d2;" size="10" maxlength="30"> <input type="Submit" value="Submit"> </form>
<input>	input field	Example 3: <form method=post action="/cgi-bin/example.cgi"> <table border="0" cellspacing="0" cellpadding="2"><tr><td bgcolor="#8463ff"><input type="text" size="10" maxlength="30"></td><td bgcolor="#8463ff" valign="Middle"> <input type="image" name="submit" src="yourimage.gif"></td></tr> </table> </form>
<input>	input field	Example 4: <form method=post action="/cgi-bin/example.cgi"> Enter Your Comments:<br> <textarea wrap="virtual" name="Comments" rows=3 cols=20 maxlength=100></textarea><br> <input type="Submit" value="Submit"> <input type="Reset" value="Clear"> </form>
<input>	input field	Example 5: <form method=post action="/cgi-bin/example.cgi"> <center> Select an option: <select> <option >option 1</option> <option selected>option 2</option> <option>option 3</option> <option>option 4</option> <option>option 5</option> <option>option 6</option> </select><br> <input type="Submit" value="Submit"></center> </form>
<input>	input field	Example 6: <form method=post action="/cgi-bin/example.cgi"> Select an option:<br> <input type="radio" name="option"> Option 1 <input type="radio" name="option" checked> Option 2 <input type="radio" name="option"> Option 3 <br> <br> Select an option:<br> <input type="checkbox" name="selection"> Selection 1 <input type="checkbox" name="selection" checked> Selection 2 <input type="checkbox" name="selection"> Selection 3 <input type="Submit" value="Submit"> </form>
<li>	list item	Example 1: <menu> <li type="disc">List item 1</li> <li type="circle">List item 2</li> <li type="square">List item 3</li> </MENU> Example 2: <ol type="i"> <li>List item 1</li> <li>List item 2</li> <li>List item 3</li> <li>List item 4</li> </ol>
<link>	link	<head> <link rel="stylesheet" type="text/css" href="style.css" /> </head>
<marquee> (Internet Explorer)	scrolling text	<marquee bgcolor="#cccccc" loop="-1" scrollamount="2" width="100%">Example Marquee</marquee>
<menu>	menu	<menu> <li type="disc">List item 1</li> <li type="circle">List item 2</li> <li type="square">List item 3</li> </menu>
<meta>	meta	<meta name="Description" content="Description of your site"> <meta name="keywords" content="keywords describing your site">
<meta>	meta	<meta HTTP-EQUIV="Refresh" CONTENT="4;URL=http://www.yourdomain.com/">
<meta>	meta	<meta http-equiv="Pragma" content="no-cache">
<meta>	meta	<meta name="rating" content="General">
<meta>	meta	<meta name="robots" content="all">
<meta>	meta	<meta name="robots" content="noindex,follow">
<ol>	ordered list	Numbered <ol> <li>List item 1</li> <li>List item 2</li> <li>List item 3</li> <li>List item 4</li> </ol> Numbered Special Start <ol start="5"> <li>List item 1</li> <li>List item 2</li> <li>List item 3</li> <li>List item 4</li> </ol> Lowercase Letters <ol type="a"> <li>List item 1</li> <li>List item 2</li> <li>List item 3</li> <li>List item 4</li> </ol> Capital Letters <ol type="A"> <li>List item 1</li> <li>List item 2</li> <li>List item 3</li> <li>List item 4</li> </ol> Capital Letters Special Start <ol type="A" start="3"> <li>List item 1</li> <li>List item 2</li> <li>List item 3</li> <li>List item 4</li> </ol> Lowercase Roman Numerals <ol type="i"> <li>List item 1</li> <li>List item 2</li> <li>List item 3</li> <li>List item 4</li> </ol> Capital Roman Numerals <ol type="I"> <li>List item 1</li> <li>List item 2</li> <li>List item 3</li> <li>List item 4</li> </ol> Capital Roman Numerals Special Start <ol type="I" start="7"> <li>List item 1</li> <li>List item 2</li> <li>List item 3</li> <li>List item 4</li> </ol>
<option>	listbox option	<form method=post action="/cgi-bin/example.cgi"> <center> Select an option: <select> <option>option 1</option> <option selected>option 2</option> <option>option 3</option> <option>option 4</option> <option>option 5</option> <option>option 6</option> </select><br> </center> </form>
<p>	paragraph	This is an example displaying the use of the paragraph tag. <p> This will create a line break and a space between lines. Attributes: Example 1:<br> <br> <p align="left"> This is an example<br> displaying the use<br> of the paragraph tag.<br> <br> Example 2:<br> <br> <p align="right"> This is an example<br> displaying the use<br> of the paragraph tag.<br> <br> Example 3:<br> <br> <p align="center"> This is an example<br> displaying the use<br> of the paragraph tag.
<small>	small (text)	<small>Example</small>
<strike>	deleted text	<strike>Example</strike>
<strong>	strong emphasis	<strong>Example</strong>
<table>	table	Example 1: <table border="4" cellpadding="2" cellspacing="2" width="100%"> <tr> <td>Column 1</td> <td>Column 2</td> </tr> </table> Example 2: (Internet Explorer) <table border="2" bordercolor="#336699" cellpadding="2" cellspacing="2" width="100%"> <tr> <td>Column 1</td> <td>Column 2</td> </tr> </table> Example 3: <table cellpadding="2" cellspacing="2" width="100%"> <tr> <td bgcolor="#cccccc">Column 1</td> <td bgcolor="#cccccc">Column 2</td> </tr> <tr> <td>Row 2</td> <td>Row 2</td> </tr> </table>
<td>	table data	<table border="2" cellpadding="2" cellspacing="2" width="100%"> <tr> <td>Column 1</td> <td>Column 2</td> </tr> </table>
<th>	table header	<div align="center"> <table> <tr> <th>Column 1</th> <th>Column 2</th> <th>Column 3</th> </tr> <tr> <td>Row 2</td> <td>Row 2</td> <td>Row 2</td> </tr> <tr> <td>Row 3</td> <td>Row 3</td> <td>Row 3</td> </tr> <tr> <td>Row 4</td> <td>Row 4</td> <td>Row 4</td> </tr> </table> </div>
<title>	document title	<title>Title of your HTML page</title>
<tr>	table row	<table border="2" cellpadding="2" cellspacing="2" width="100%"> <tr> <td>Column 1</td> <td>Column 2</td> </tr> </table>
<tt>	teletype	<tt>Example</tt>
<u>	underline	<u>Example</u>
<ul>	unordered list	Example 1:<br> <br> <ul> <li>List item 1</li> <li>List item 2</li> </ul> <br> Example 2:<br> <ul type="disc"> <li>List item 1</li> <li>List item 2</li> <ul type="circle"> <li>List item 3</li> <li>List item 4</li> </ul> </ul>

Localization in ASP.NET

2013-03-24T23:48:00.001-07:00

Website Localization

Localization

http://msdn.microsoft.com/en-us/magazine/cc302030.aspx

http://msdn.microsoft.com/en-us/magazine/bb986108.aspx

Date.aspx

<%@ Page Language="C#" %>

<html>

<body>

<h1>

<% Response.Write (DateTime.Now.ToShortDateString ()); %>

</h1>

</body>

</html>

Global.asax

<%@ Import Namespace="System.Threading" %>

<%@ Import Namespace="System.Globalization" %>

void Application_BeginRequest (Object sender, EventArgs e)

{

try {

if (Request.UserLanguages.Length > 0) {

Thread.CurrentThread.CurrentCulture =

CultureInfo.CreateSpecificCulture

(Request.UserLanguages[0]);

}

catch (ArgumentException) {

// Do nothing if CreateSpecificCulture fails

}

</script>

Run the webform . Now go to Tools | Internet Options | General and click on the Languages button to add "French (France) [fr]" to your language preferences and place it at the top of the list. Request Date.aspx again and the page will look quite different (see Figure 4). Include an Application_BeginRequest handler like the one in Figure 2 in every Web app you deploy and you'll gain a measure of culture awareness free of charge.

HTTP Handlers

2013-03-24T23:47:00.000-07:00

C#.net training Http Handler

An ASP.NET handler that returns a dynamically generated image

<%@ WebHandler Language="C#" Class="ImageHandler" %>

using System;

using System.Drawing;

using System.Drawing.Imaging;

using System.IO;

using System.Web;

using System.Web.Caching;

public class ImageHandler : IHttpHandler {

public void ProcessRequest (HttpContext context) {

// Get the image ID from querystring, and use it to generate a cache key.

String imageID = context.Request.QueryString["PhotoID"];

String cacheKey = context.Request.CurrentExecutionFilePath + ":" + imageID;

Byte[] imageBytes;

// Check if the cache contains the image.

Object cachedImageBytes = context.Cache.Get(cacheKey);

if (cachedImageBytes != null)

{

imageBytes = (Byte[])cachedImageBytes;

}

else

{

// Get image from business layer, and save it into a Byte array as JPEG.

Image im = PhotoLibrary.GetImage("PhotoID");

MemoryStream stream = new MemoryStream();

im.Save(stream, ImageFormat.Jpeg);

stream.Close();

im.Dispose();

imageBytes = stream.GetBuffer();

// Store it in the cache (to be expired after 2 hours).

context.Cache.Add(cacheKey, imageBytes, null,

DateTime.MaxValue, new TimeSpan(2, 0, 0),

CacheItemPriority.Normal, null);

}

// Send back image.

context.Response.ContentType = "image/jpeg";

context.Response.Cache.SetCacheability(HttpCacheability.Public);

context.Response.BufferOutput = false;

context.Response.OutputStream.Write(imageBytes, 0, imageBytes.Length);

}

public bool IsReusable {

get {

return false;

}

Use HTTP Handlers to Generate Images Dynamically

http://msdn.microsoft.com/en-us/magazine/cc302030.aspx

Including an image in a Web page is as simple as inserting an <img> tag into the page's HTML. The following statement displays the image in the file named Logo.jpg:

<img src="logo.jpg">

This is fine and good if Logo.jpg contains a static image that can be generated absent any user input. But what if you want to build a Web page that displays images built at run time from user input—for example, a page that graphs user-supplied data or values obtained from a database? The simple answer is that you create the image on the server and return an <img> tag that references it. The reality is that dynamic image generation is easier said than done

PieChart.aspx

<html>

<body>

<tr>

<td>

<tr>

</tr>

<tr>

</tr>

<tr>

</tr>

<tr>

</tr>

<tr>

<asp:Button Text="Show Chart" OnClick="OnShowChart"

RunAt="server" />

</td>

</tr>

</table>

</td>

<td>

<asp:Image ID="Chart" AlternateText="Pie Chart"

RunAt="server" />

</td>

</tr>

</table>

</form>

</body>

</html>

void OnShowChart (Object sender, EventArgs e)

{

Chart.ImageUrl = String.Format

("PieChart.ashx?q1={0}&q2={1}&q3={2}&q4={3}" +

"&width=256&height=224", Q1.Text, Q3.Text, Q3.Text,

Q4.Text);

}

</script>

PieChart.ashx

<%@ WebHandler Language="C#" Class="PieChartGenerator" %>

using System;

using System.Web;

using System.Drawing;

using System.Drawing.Imaging;

public class PieChartGenerator : IHttpHandler

{

public void ProcessRequest (HttpContext context)

{

// Extract input parameters from the query string

decimal[] vals = new decimal[4];

vals[0] = Convert.ToDecimal (context.Request["q1"]);

vals[1] = Convert.ToDecimal (context.Request["q2"]);

vals[2] = Convert.ToDecimal (context.Request["q3"]);

vals[3] = Convert.ToDecimal (context.Request["q4"]);

int width = Convert.ToInt32 (context.Request["width"]);

int height = Convert.ToInt32 (context.Request["height"]);

// Create a bitmap, draw a pie chart, and write it to the

// response.

Bitmap bitmap = new Bitmap (width, height,

PixelFormat.Format32bppArgb);

Graphics g = Graphics.FromImage (bitmap);

DrawPieChart (g, Color.White, vals, width, height);

context.Response.ContentType = "image/gif";

bitmap.Save (context.Response.OutputStream, ImageFormat.Gif);

// Clean up and return.

bitmap.Dispose ();

g.Dispose ();

}

public bool IsReusable

{

get { return true; }

}

void DrawPieChart (Graphics g, Color bkgnd, decimal[] vals,

int width, int height)

{

// Erase the background.

SolidBrush br = new SolidBrush (bkgnd);

g.FillRectangle (br, 0, 0, width, height);

br.Dispose ();

// Create an array of brushes.

SolidBrush[] brushes = new SolidBrush[6];

brushes[0] = new SolidBrush (Color.Red);

brushes[1] = new SolidBrush (Color.Yellow);

brushes[2] = new SolidBrush (Color.Blue);

brushes[3] = new SolidBrush (Color.Cyan);

brushes[4] = new SolidBrush (Color.Magenta);

brushes[5] = new SolidBrush (Color.Green);

// Sum the inputs.

decimal total = 0.0m;

foreach (decimal val in vals)

total += val;

// Draw the chart.

float start = 0.0f;

float end = 0.0f;

decimal current = 0.0m;

for (int i=0; i<vals.Length; i++) {

current += vals[i];

start = end;

end = (float) (current / total) * 360.0f;

g.FillPie (brushes[i % 6], 0.0f, 0.0f, width, height,

start, end - start);

}

// Clean up and return.

foreach (SolidBrush brush in brushes)

brush.Dispose ();

}

it includes an image control that initially displays no image at all because its ImageUrl property is unassigned. Clicking the Show Chart button activates the OnShowChart method on the server. OnShowChart builds a URL complete with a query string containing user input and assigns it to the Image control. Entering the values 100, 200, 300, and 400 into the four TextBoxes produces the following URL:

piechart.ashx?q1=100&q2=200&q3=300&q4=400&width=256&height=224

Note the resource identified in the URL: PieChart.ashx. Inside PieChart.ashx is an HTTP handler that generates pie charts from the inputs in the query string. The @ WebHandler directive at the top of the file informs ASP.NET that PieChart.ashx contains an HTTP handler. ASP.NET automatically compiles and executes the handler when the ASHX file is requested. No special registration is required because Machine.config maps ASHX files to a handler that knows how to compile and run other HTTP handlers.

ASP.NET Themes

2013-03-24T23:42:00.002-07:00

Website themes

Apply ASP.NET Themes

Themes are made up of a set of elements: skins, cascading style sheets (CSS), images, and other resources. At a minimum, a theme will contain skins. Themes are defined in special directories in your Web site or on your Web server.

Skins

A skin file has the file name extension .skin and contains property settings for individual controls such as Button, Label,TextBox, or Calendar controls. Control skin settings are like the control markup itself, but contain only the properties you want to set as part of the theme. For example, the following is a control skin for a Button control:

<asp:button runat="server" BackColor="lightblue" ForeColor="black" />

You can apply themes to a page, a Web site, or globally. Setting a theme at the Web site level applies styles and skins to all the pages and controls in the site unless you override a theme for an individual page. Setting a theme at the page level applies styles and skins to that page and all its controls.
By default, themes override local control settings. Alternatively, you can set a theme as a style sheet theme, so that the theme applies only to control settings that are not explicitly set on the control.

To apply a theme to a Web site

1. In the application's Web.config file, set the <pages> element to the name of the theme, either a global theme or a page theme, as shown in the following example:

<configuration>

    <system.web>

        <pages theme="ThemeName" />

    </system.web>

</configuration>

To apply a theme to an individual page

Set the Theme or StyleSheetTheme attribute of the @ Page directive to the name of the theme to use, as shown in the following example:

<%@ Page Theme="ThemeName" %>

<%@ Page StyleSheetTheme="ThemeName" %>

kins defined in your theme apply to all control instances in the application or pages to which the theme is applied. In some cases, you might want to apply a specific set of properties to an individual control. You can do that by creating a named skin (an entry in a .skin file that has a SkinID property set) and then applying it by ID to individual controls.

Applying Skins to Controls
Skins defined in your theme apply to all control instances in the application or pages to which the theme is applied. In some cases, you might want to apply a specific set of properties to an individual control. You can do that by creating a named skin (an entry in a .skin file that has a SkinID property set) and then applying it by ID to individual controls.

To apply a named skin to a control

· Set the control's SkinID property, as shown in the following example:

<asp:Calendar runat="server" ID="DatePicker" SkinID="SmallCalendar" />

If the page theme does not include a control skin that matches the SkinID property, the control uses the default skin for that control type.

ASP.NET Request Life Cycle

2013-03-24T23:38:00.001-07:00

ASP.NET Development life cycle

ASP.NET Request Life Cycle

When an ASP.NET page runs, the page goes through a life cycle in which it performs a series of processing steps. These include initialization, instantiating controls, restoring and maintaining state, running event handler code, and rendering. It is important for you to understand the page life cycle so that you can write code at the appropriate life-cycle stage for the effect you intend.
If you develop custom controls, you must be familiar with the page life cycle in order to correctly initialize controls, populate control properties with view-state data, and run control behavior code. The life cycle of a control is based on the page life cycle, and the page raises many of the events that you need to handle in a custom control.
This topic contains the following sections:

· General Page Life-cycle Stages

· Life-cycle Events

· Additional Page Life Cycle Considerations

· Catch-Up Events for Added Controls

· Data Binding Events for Data-Bound Controls

· Login Control Events

Visit

http://msdn.microsoft.com/en-us/library/ms178472.aspx

ASP.NET 4. 0 Introduction

2013-03-24T23:35:00.003-07:00

learn asp.net

Introduction to ASP.NET 4. 0

• ASP.NET is the name of the Microsoft technology used for web site development.
• ASP.NET is NOT a programming language like C# or VB.NET
• ASP.NET development requires a programming language like C# or VB.NET to write code.
• ASP stands for Active Server Pages.
• There are several other technologies exist for web development (Eg: PHP). ASP.NET is the technology from Microsoft and it he widely used one.
• ASP.NET technology comes with a rich set of components and controls that make the web development very easy.
• Visual Studio .NET is the editor from Microsoft which helps you develop ASP.NET web sites faster and easily.
In ASP.NET programming, a web page is developed using HTML and a .NET programming language like C#, VB.NET or J#. You can choose your favourite .NET language to develop ASP.NET pages.

Creating a new Website

First step in creating a new website is to open the application VISUAL STUDIO 2010. The second one is to select ”New Web Site” from File tab. You can select ASP.NET WebSite or Empty WebSite. ASP.NET WebSite will appear with a Master page and almost gives the structure of a website. But there is unnessary things which we dont want in our site. So it’s better to create an Empty WebSite rather than modifying an existing site.

From the newer menu select the programming language (Visual Basic or Visual C#). We will select the location where do we want to create the website (it can also be a FTP address) and the type of the website.

Displaying The Interface

• In the upper left side, in Toolbox you will find all the controls that can be added into a website.
• In Server Explorer you can see the database attached to the website (in this moment it isn’t attached ).
• In center you can see the visual side of the website .
• In the right side you find the Solution Explorer where you can see all the files of the website and Properties where you find the properties of the selected object.
Site.Master (a page of the website)--- Using this you will build the other pages, adding just content letting the design intact.
To add a new page go to Website menu and select Add New Item. Will appear a new window from where you can select the type of the page and the name.
To view the website on localhost you have to select from the menu Debug and Start Debugging.
The database and the tables where will be saved users names and details about them will be created automatically.
After you create a new page will be created a new file .cs where will be written the codes

Server side Scripting

The dynamic pages are created using code in asp.net web pages. When you request a page, the web server executes the code in the web page and generates an HTML content for that page. It is this HTML content that is sent back to the browser so that it can be displayed to the user.

The code that is executed by the web server to generate the dynamic page is called "server side code". It is called "server side code" because it is executed by the web server.

When you develop ASP.NET pages, you will use C# or VB.NET (or any other .NET compatible code) code to write the server side code. Server side code is used to retrieve and generate content for the dynamic pages. You may be using the code to retrieve the content from database or something like that.

When a dynamic page is requested, the server side code is executed on the server and a page is generated. Once the generated page comes to the browser, there is connection with the server. You cannot do anything from the browser to communicate with the server, othen than requesting another page or same page again. So, if you want to access the database or something like that once the page is displayed, it is not possible.

Client side scripting

Client side code is used to do some kind of basic operations in the browser when the page is displayed to the user.

As you read above, it is not possible to access the server once the page is displayed. Morover, the browser does not know anything about ASP.NET or .NET. The browser understands only HTML and client side scripting languages.

Client side coding is used to do basic operations on the browser. It cannot be used to access the server or database on the server etc.

Client side coding is done using scripting languages like Javascript, VbScript, JScript etc. These scripting languages are easy to learn (they are different from vb.net and C#). The scripting languages provide only very minimal functionality.

The main use of client side scripting is to validate user input before submitting a page to server. For example, suppose you have a "Registration" page. Once user enter all data and press the "submit" button, all the user input will be sent to server. In the server side, you may have written vb.net or C# code to validate all user inputs like Name cannot be empty etc. If the user do not enter a name and press submit, your server side code will generate an error message and return the page to you.

In this case, the page was sent to the server and came back with an error message. It was an expensive operation. It consumed lot of resources to send a page to the server and get it back to the browser with an error message.

If we can catch this validation error in the browser itself, instead of sending to server and coming back with an error, that will save lot of time and resources. User need not wait to send the page to server and come back.

Since, a browser does not know VB.NET or C#, you cannot write such code to validate it in the browser.

Client side scripting comes here to help. You can write Javascript, VBScript or JScript code to validate the name field in the browser itself and submit it to the server only if all user inputs are correct.

JavaScript has the following unique features:

JavaScript is a scripting language - Source code is interpreted, instead of compiled and executed. Like most other interpreted languages, it does support the eval(source_code) function.
JavaScript is a dynamic typing language - Data types are associated with values, instead of variables. In other words, variables are declared without specific data types. They can be assigned with values of any data type.
JavaScript is a prototype-based language - Prototypes, instead of classes, are used for defining object properties, methods, and inheritance.
JavaScript uses associative arrays to represent objects - Property names and values are stored as associative array elements. Properties and their values can be added, changed, or deleted at run-time.
JavaScript supports functions as first-class functions - Functions are really objects. Like regular objects, functions can be created during execution, stored in data structure, and passed to other functions as arguments.

Eg: <html>

<head><title>Hello World! </title></head>

<body>

document.write('Hello World!');

</script>

</body>

</html>

HTML

HTML stands for the HyperText Markup Language. Web sites are created with the codes of the HTML language. HTML is extremely easy to learn, and it's completely free to code web sites with it. HTML allows web sites to bring together graphics, music, video and links. The HTML code you type can be viewed on any computer. If you type it on a Windows PC, it can be viewed on both Windows and Apple computers, and if you type it on an Apple Mac, you can view it on both Macs and PCs. It doesn't matter what computer someone uses, as long as it has Internet access.

web server

A Web server is a software program which serves web pages to web users (browsers).

A web server delivers requested web pages to users who enter the URL in a web browser. Every computer on the Internet that contains a web site must have a web server program.

The computer in which a web server program runs is also usually called a "web server". So, the term "web server" is used to represent both the server program and the computer in which the server program runs.

Characteristics of web servers

A web server computer is just like any other computer. The basic characteristics of web servers are:

- It is always connected to the internet so that clients can access the web pages hosted by the web server.
- It has an application called 'web server' running always.

In short, a 'web server' is a computer which is connected to the internet/intranet and has a software called 'web server'. The web server program will be always running in the computer. When any user try to access a website hosted by the web server, it is actually the web server program which delivers the web page which client asks for.
A web server can hosted hundreds of web sites. Most of the small web sites in the internet are hosted on shared web servers.

Examples of web server applications

1. IIS
2. Apache

ASP.NET Web Forms 4.0 at a Glance

The key words to describe what's new in the overall ASP.NET 4.0 platform are "more control." ASP.NET 4.0 is neither a revolutionary change nor a refactoring of its existing architecture. It consists, instead, of a good number of small-scale changes that together provide developers with much more control of certain frequently used features of the existing framework.

For example, ASP.NET 4.0 Web Forms give developers more control over viewstate management, generation of IDs in the context of data-bound controls, and HTML generated by some template-based controls. In addition, you'll find new families of pluggable components for features that weren't supporting the provider 2009 model in earlier versions of ASP.NET and a finer control over the linking of external script files through the ScriptManager control.

More notes visit

http://msdn.microsoft.com/en-us/library/s57a598e.aspx

http://msdn.microsoft.com/en-us/magazine/ee431529.aspx

Common Language Runtime

2013-03-23T01:59:00.003-07:00

The Common Language Runtime (CLR)

Microsoft's CLR implements the Common Language Infrastructure

Common Type System (CTS) - This defines the rules for defining data types irrespective of the source language used.
Common Language Specification (CLS) - This is a subset of the CTS. It is a set of types that may be used in external calls in code that is intended to be portable.
Microsoft Intermediate Language (MSIL) - This is the set of machine instructions defined for use with all .NET languages. The Intermediate code is platform independent, but not automatically type safe, as in C++. Also referred to as managed code and managed data.
Metadata - This is information associated with the managed code and data that describes the data, identifies the locations of references to objects, and gives the Virtual Execution System information to handle overhead of older programming models.
J IT Compiler - This converts the MSIL into native code of the operating system.
Garbage Collector (GC) - This manages the memory when the code is running in the VES( Virtual Execution System). Every so often the GC inspects the memory in use by the computer and removes anything that is no longer needed by the .NET application that is running in the VES. This does not mean that code can be written so that the GC tidies everything up, but instead it should be used as an aid to making applications run smoothly.
Virtual Execution System (VES) - This is the part of the system that runs and manages .NET code at runtime in a similar manner to the Java Virtual Machine for the Java Language. The VES sits between the managed code and the native operating system.

At a high level, the CLR is responsible for basic system services such as

memory management
threading
error control
type safety

. The runtime automatically handles object layout and manages references to objects, releasing them when they are no longer being used, through the use of a Garbage Collector.

Features of C# 4.0

The main features in C# 4.0 are:

• Dynamic binding

• Type variance with generic interfaces and delegates

• Optional parameters

• Named arguments

• COM interoperability improvements

Dynamic binding is C# 4.0’s biggest innovation. This feature was inspired by dynamic languages such as Python, Ruby, JavaScript, and Smalltalk.Dynamic binding defers binding—the process of resolving types and members—from compile time to runtime. Although C# remains a predominantly statically typed language, a variable of type dynamic is resolved in a late-bound manner.

For example:

dynamic d = "hello";

Console.WriteLine (d.ToUpper()); // HELLO

Console.WriteLine (d.Foo()); // Compiles OK but gives runtime error

Calling an object dynamically is useful in scenarios that would otherwise require complicated reflection code. Dynamic binding is also useful when interoperating with dynamic languages and COM components.

Optional parameters allow functions to specify default parameter values so that callers can omit arguments. An optional parameter declaration such as:

void Foo (int x = 23) { Console.WriteLine (x); }

can be called as follows:

Foo(); // 23

Named arguments allow a function caller to identify an argument by name rather than position. For example, the preceding method can now be called as follows:

Foo (x:5);

Type variance allows generic interfaces and generic delegates to mark their type parameters as covariant or contravariant. This enables code such as the following to work:

IEnumerable<string> x = ...;

IEnumerable<object> y = x;

COM interoperability has been enhanced in C# 4.0 in three ways. First,

arguments can be passed by reference without the ref keyword. This feature is particularly

useful in conjunction with optional parameters

State management in ASP.NET

2013-03-21T04:05:00.002-07:00

asp.net tutorial state management

State Management in ASP.NET

ASP.NET offers a number of places to store state, both on the client and server. However, sometimes it's difficult to decide where you should put things and how to make that decision.

Choices for state management include:

• Application

• Cache

• Session

• ViewState

• Cookies

• QueryString

• Context.Items

• Profile

Types of State management

2 types:

Client – Side State Management
Server - Side State Management

Client – Side State Management:

Stores information on the client's computer

Techniques:

1. View State:

Stored in a hidden page input (by
default).
Does not expire.
Track the values in the Controls

2. Control State:

created to ensure working of viewstate

3. Hidden fields:

store data in an HTML form

4. Cookies:

Stored at the client.
Can expire.
Store state data at client required on multiple pages of website

5. Query Strings:

Passed in the URL.
Must be maintained with each request.
Store values in the URL that are visible to the user

Server – Side State Management

1.Application State:

Stored on the server and shared for all users.
Does not expire.
Deprecated by Cache

2.Session State :

Stored on the server.
Unique for each user.
Can expire.
Available to all pages opened by a user during a single visit.

ASP.NET session state supports several different storage options for session data:

a. InProc Stores session state in memory on the Web server.

b. StateServer Stores session state in a service called the ASP.NET State Service.

c. SQLServer Stores session state in a SQL Server database.

d. Custom Enables you to specify a custom storage provider. You also need to implement the custom storage provider.

e. Off Disables session state. You should disable session state if you are not using it to improve performance.

Constructors in C#.NET

2013-03-21T03:32:00.004-07:00

C# training Constructors

Constructors with examples in C#.NET

A special method of the class that will be automatically invoked when an instance of the class is created is called as constructor. So we can say a constructor is a public method, which is automatically invoked when an object is created.
Now we will see some of the peculiarities of constructors

Constructors have the same name as that of the class name
It has no return type not even void
Constructor must be declared with the keyword 'public'
Constructors can be overloaded , that means we can pass parameters along with a constructor.

Constructors can be classified into 5 types

1. Default Constructor
2. Parameterized Constructor
3. Copy Constructor
4. Static Constructor
5. Private Constructor

Default Constructor : A constructor without any parameters is called as default constructor. Drawback of default constructor is every instance of the class will be initialized to same values and it is not possible to initialize each instance of the class to different values.

Example for Default Constructor

using System;

//Example Class to check whether number is even or not

class Even
{
    private int no;

    //Default Constructor
    public Even()
    {
        this.no= 2;
    }

    public void check()
    {
if (n % 2 ==0)
Console.WriteLine(n +" is even number");
else
Console.WriteLine(n +" is odd number");

    }

}

//Using Class in the program
class MyMain
{

    public static void Main()
    {
        //Calling Default Constructor
Even evobj= new Even();
   evobj.check();
Console.Read();
}
  }

Parameterized Constructor : A constructor with at least one parameter is called as parameterized constructor. Advantage of parameterized constructor is you can initialize each instance of the class to different values.

Example for Parameterized Constructor

using System;

//Example Class to check whether number is even or not

class Even

{

private int no;

//Default Constructor

public Even()

{

this.no= 2;

}

//Paramerized Constructor

public Even(int no)

{

//A Constructor is used to initilize private fields of a class

this.no= no;

}

public void check()

{

if (n % 2 ==0)

Console.WriteLine(n +" is even number");

else

Console.WriteLine(n +" is odd number");

}

//Using Class in the program

class MyMain

{

public static void Main()

{

//Calling Parametrized Constructor

Even evobj= new Even(5);

evobj.check();

Console.Read();

}

Copy Constructor : A parameterized constructor that contains a parameter of same class type is called as copy constructor. Main purpose of copy constructor is to initialize new instance to the values of an existing instance.

Example for Copy Constructor

using System;

class Test
{

int A, B;

public Test(int X, int Y)
{
A = X;
B = Y;
}

//Copy Constructor
public Test(Test T)
{
A = T.A;

B = T.B;
}

public void Print()
{

Console.WriteLine("A = {0}\tB = {1}", A, B);
}

}

class CopyConstructor
{
static void Main()
{

Test T1 = new Test(80, 90);

//Invoking copy constructor
Test T2 = new Test(T1);

T1.Print();
T2.Print();

Console.Read();
}
}

Output

A = 80 B = 90
A = 80 B = 90

Static Constructor : You can create a constructor as static and when a constructor is created as static, it will be invoked only once for any number of instances of the class and it is during the creation of first instance of the class or the first reference to a static member in the class. Static constructor is used to initialize static fields of the class and to write the code that needs to be executed only once.

Example for Static Constructor

using System;

class Test
{

public Test()
{

Console.WriteLine("Instance Constructor invoked");
}

static Test()
{
Console.WriteLine(" Static Constructor invoked");
}
}

class StaticConstructorTesting
{
static void Main()
{
//Static Constructor and instance constructor, both are invoked for first instance.
Test T1 = new Test();

//Only instance constructor is invoked.
Test T2 = new Test();

Console.Read();
}
}
}

Output

Static Constructor invoked
Instance Constructor invoked
Instance Constructor invoked

Private Constructor : You can also create a constructor as private. When a class contains at least one private constructor, then it is not possible to create an instance for the class. Private constructor is used to restrict the class from being instantiated when it contains every member as static.

Some unique points related to constructors are as follows

• A class can have any number of constructors.
• A constructor doesn’t have any return type even void.
• A static constructor can not be a parameterized constructor.
• Within a class you can create only one static constructor.