C# and ASP.Net blogs

Conditionally Styling a columns rows in GridView Control

2015-03-15T20:52:00.002+05:30

In .aspx.cs file Write the following code:
private static int count = 0;
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack)
{
SqlConnection cn = new SqlConnection("data source=your sql server name;initial catalog=your db name;integrated security=sspi");
string qry = "select * from employees";
SqlCommand cmd = new SqlCommand(qry, cn);
cn.Open();
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = cmd;
DataSet ds = new DataSet();
da.Fill(ds);
cn.Close();
Session["ds"] = ds;
gvEmps.DataSource = ds;
DataTable dt = ds.Tables[0];
DataColumn dc = new DataColumn("Eligibility",typeof(string));
dt.Columns.Add(dc);
gvEmps.DataBind();
}
}
protected void gvEmps_RowDataBound(object sender, GridViewRowEventArgs e)
{

if (count > 0)
{
GridViewRow gvr = e.Row;
TableCell tc = gvr.Cells[3];

string data = tc.Text;
if (data != " "&&data!="doj")
{
DateTime dt = Convert.ToDateTime(data);
int yrsDiff = DateTime.Now.Year - dt.Year;
if (yrsDiff >= 5)
{
TableCell tc1 = gvr.Cells[4];
tc1.Text = "Eligible";
tc1.Style.Add("color", "red");
}
}
}
if (count == 0)
{
count = 1;
}
}
Table Structure:

eid	fname	age	doj	Eligibility
1	rijin	23	04-Oct-09 12:00:00 AM	Eligible
2	kishore	23	04-Oct-14 12:00:00 AM

Gridview with Hyperlink sample code

2014-08-03T18:16:00.000+05:30

In .aspx file:

<asp:GridView ID="gvProducts" runat="server" AutoGenerateColumns="false">
<AlternatingRowStyle BackColor="green" />
<Columns>
<asp:HyperLinkField HeaderText="Name" DataTextField="PName"
DataNavigateUrlFields="pname"
DataNavigateUrlFormatString="Sales.aspx?pname={0}" />
<asp:BoundField HeaderText="MinQty" DataField="MinOrdQty" />
<asp:BoundField HeaderText="MaxQty" DataField="MaxOrdQty" />
<asp:BoundField HeaderText="UnitPrice" DataField="UnitPrice" />
</Columns>
</asp:GridView>

In .aspx.cs file:

protected void Page_Load(object sender, EventArgs e)
{
string strcn = "Data source=name-of-sql-server;initial catalog=database-name;integrated security=sspi";
SqlConnection cn = new SqlConnection(strcn);
SqlCommand cmd = new SqlCommand("select pname,minordqty,MaxOrdQty,UnitPrice from dbo.products", cn);
try
{
cn.Open();
DataSet ds = new DataSet();
SqlDataAdapter DA = new SqlDataAdapter(cmd);
DA.Fill(ds);
DataTable dt = ds.Tables[0];
//Session["ds"] = ds;
gvProducts.DataSource = dt;
gvProducts.DataBind();

}
catch (SqlException ex)
{

}
finally
{
cn.Close();
}
}
In Details page (Sales.aspx) :
<asp:GridView ID="gvSales" runat="server"></asp:GridView>

In Sales.aspx.cs:

protected void Page_Load(object sender, EventArgs e)
{
if (Request.QueryString["pname"] != null)
{
string productName = Request.QueryString["pname"].ToString();
if (productName != null && productName != string.Empty)
DisplaySalesDetails(productName);
}
}
private void DisplaySalesDetails(string pname)
{
string strcn = "Data source=ADMIN-PC\\SQLEXPRESS;initial catalog=adomaterial;integrated security=sspi";
SqlConnection cn = new SqlConnection(strcn);
string qry=@"select * from dbo.sales where pid in(select pid from products
where pname='";
qry+=pname+"');";
SqlCommand cmd = new SqlCommand(qry,cn);
try
{
cn.Open();
DataSet ds = new DataSet();
SqlDataAdapter DA = new SqlDataAdapter(cmd);
DA.Fill(ds);
Session["ds"] = ds;
gvSales.DataSource = ds;
gvSales.DataBind();

}
catch (SqlException ex)
{

}
finally
{
cn.Close();
}
}
Table structure:
Products table:

Pid	PName	Mid	MinOrdQty	MaxOrdQty	UnitPrice
1	colgate	1	50	500	65
2	DoveSoap	1	100	1000	25
3	DoveShampoo	1	50	500	150
4	ParachuteOil	2	20	50	80
5	RinSoap	2	50	500	15
6	SurfExcel	1	50	500	55
7	VIM	2	10	100	15
8	EXO	3	10	150	35
9	Medimix	3	25	150	25
10	Pears	4	10	200	26
11	NoteBook	4	51	270	48
12	Cinthol		20	300	23
13	fiama	4	20	200	67

Sales table:

Sid	Qty	OriginalPrice	TotalPrice	Discount	SaleDate	Pid
1	10	1350	1200	150	23-Dec-11 12:00:00 AM	3
2	25	2000	1800	200	21-Aug-11 12:00:00 AM	4
3	20	1300	1000	300	13-Jun-10 12:00:00 AM	1
4	150	5500	4900	600	23-Dec-09 12:00:00 AM	6
5	50	1300	1100	200	02-Jun-08 12:00:00 AM	10
6	15	375	350	25	01-Feb-12 12:00:00 AM	2
7	25	3375	3100	275	02-Feb-11 12:00:00 AM	3
8	200	3000	2500	500	07-Oct-10 12:00:00 AM	5
9	150	3300	3200	100	29-Jul-11 12:00:00 AM	9
10	100	3500	3200	300	15-Nov-10 12:00:00 AM	8
11	10	550	500	50	02-Feb-11 12:00:00 AM	6
12	50	1100	1000	100	11-Aug-09 12:00:00 AM	9
13	80	1200	950	250	23-Dec-10 12:00:00 AM	7
14	100	2500	900	400	20-Oct-11 12:00:00 AM	9
15	120	1600	1500	100	03-Oct-12 12:00:00 AM	7

Paging in GridView

2014-07-22T10:02:00.002+05:30

In .aspx file :

<asp:GridView ID="GridView1" runat="server" PageSize="5" AllowPaging="true" onpageindexchanging="GridView1_PageIndexChanging">
<PagerSettings Mode="Numeric" />
</asp:GridView>

In .aspx.cs file :

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

{

protected void Page_Load(object sender, EventArgs e)

{

//sspi=Security Support Provider Interface ~= trusted connection

if(!IsPostBack)

DisplayEmployees();

}

private void DisplayEmployees()

{

string strcn = "data source=ADMIN-PC\\SQLEXPRESS;initial catalog=db17;integrated security=sspi";

SqlConnection cn = new SqlConnection(strcn);

SqlCommand cmd = new SqlCommand("select * from employees", cn);

try

{

cn.Open();

DataSet ds = new DataSet();

SqlDataAdapter DA = new SqlDataAdapter(cmd);

DA.Fill(ds);

Session["ds"] = ds;

GridView1.DataSource = ds;

GridView1.DataBind();

}

catch (SqlException ex)

{

}

finally

{

cn.Close();

}

protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)

{

DataSet ds = (DataSet)Session["ds"];

DataTable dt = ds.Tables[0];

GridView1.DataSource = dt;

GridView1.PageIndex = e.NewPageIndex;//this code must be written between Datasource and DataBind

GridView1.DataBind();

}

Table structure:

eid	fname	lname	age	salary	dept	doj
1	rajeev	sukla	23	12000	.net	23-Oct-11 12:00:00 AM
2	sowmya	kumari	23	19000	db	13-Nov-10 12:00:00 AM
3	kishore	kumar	27	36000	android	16-Oct-11 12:00:00 AM
4	abimanyu	biswal	22	null	android	20-Feb-10 12:00:00 AM
5	soni	kumar	24	21800	.net	21-Jun-09 12:00:00 AM
6	anu	_singh	22	12000	db	23-Oct-10 12:00:00 AM
7	_dinesh	moh%anty	23	15000	.net	26-Aug-09 12:00:00 AM
8	nishala	_kumari	22	18000	db	19-Jul-08 12:00:00 AM
1	rajeev	sukla	23	12000	.net	23-Oct-11 12:00:00 AM

Sorting in Gridview Control

2014-07-22T09:55:00.001+05:30

Write the following code In .aspx page :

<asp:GridView ID="gvstudents" runat="server" AllowSorting="true"

OnSorting="gvstudents_sorting">

</asp:GridView>

Code in .aspx.cs:

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

{

protected void Page_Load(object sender, EventArgs e)

{

if(!IsPostBack)

{

string strcon = "data source=name of sql server ;initial catalog=database name;integrated security=sspi or user id=sqlserver userid ; password=somepassword";

string sConnection = strcon;

DataSet ds = new DataSet();

SqlConnection cn = new SqlConnection(sConnection);

using (cn)

{

SqlCommand cmd = new SqlCommand("select * from employees", cn);

using (cmd)

{

SqlDataAdapter da = new SqlDataAdapter();

da.SelectCommand = cmd;

da.Fill(ds);

gvstudents.DataSource = ds;

gvstudents.DataBind();

Session["ds"] = ds;

ViewState["sortcolumn"] = string.Empty;

ViewState["sortdirection"] = string.Empty;

}

}

}

}

protected void gvstudents_sorting(object sender, GridViewSortEventArgs e)

{

if (Session["ds"] != null)

{

DataSet ds = (DataSet)Session["ds"];

DataTable dt = ds.Tables[0];

DataView dv = dt.DefaultView;//DataView ado.net view in t-sql

if (ViewState["sortcolumn"].ToString() == e.SortExpression.ToString())

{

if ("asc" == ViewState["sortdirection"].ToString())

{

ViewState["sortdirection"] = "DESC";

}

else

{

ViewState["sortdirection"] = "asc";

}

}

else

{

ViewState["sortcolumn"] = e.SortExpression.ToString();

ViewState["sortdirection"] = "asc";

}

if (dv != null)

{

dv.Sort = e.SortExpression + " " + ViewState["sortdirection"].ToString();

//dv.Sort= "ename asc";

gvstudents.DataSource = dv;

gvstudents.DataBind();

}

}

}

}

Table structure :

eid fname lname age salary dept doj

1 rajeev sukla 23 12000 .net 23-Oct-11 12:00:00 AM

2 sowmya kumari 23 19000 db 13-Nov-10 12:00:00 AM

3 kishore kumar 27 36000 android 16-Oct-11 12:00:00 AM

4 abimanyu biswal 22 null android 20-Feb-10 12:00:00 AM

5 soni kumar 24 21800 .net 21-Jun-09 12:00:00 AM

6 anu _singh 22 12000 db 23-Oct-10 12:00:00 AM

7 _dinesh moh%anty 23 15000 .net 26-Aug-09 12:00:00 AM

8 nishala _kumari 22 18000 db 19-Jul-08 12:00:00 AM

1 rajeev sukla 23 12000 .net 23-Oct-11 12:00:00 AM

Asp.net Gridview edit update and delete code

2014-07-21T09:50:00.003+05:30

In GridViewEditUpdateDelete.aspx add the following code ( in the form tag )

<asp:GridView ID="gvPatients" AutoGenerateColumns="false" runat="server"
AutoGenerateEditButton="true" AutoGenerateDeleteButton="true"
DataKeyNames="PatientID"
onrowediting="gvPatients_RowEditing"
OnRowCancelingEdit="gvPatients_RowCancel" OnRowUpdating="gvPatients_RowUpdating"
OnRowDeleting="gvPatients_RowDeleting"
onselectedindexchanged="gvPatients_SelectedIndexChanged">
<HeaderStyle BackColor="AliceBlue" ForeColor="Red"/>
<Columns>
<asp:TemplateField HeaderText="PatientID">
<ItemTemplate>
<asp:Label ID="lblPatientID" runat="server" Text='<%#Eval("PatientID") %>'/>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="PatientName">
<EditItemTemplate>
<asp:TextBox ID="tbName" runat="server" Text='<%#Eval("PatientName")%>' />
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="lblName" runat="server" Text='<%#DataBinder.Eval(Container.DataItem,"PatientName")%>' />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="AGE">
<EditItemTemplate>
<asp:TextBox ID="tbAge" runat="server" Text='<%#Eval("age")%>' />
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="lblAge" runat="server" Text='<%#Eval("age")%>' />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>

In .aspx.cs page add the following code:

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

{

DataSet ds = new DataSet();

protected void Page_Load(object sender, EventArgs e)

{

if (!IsPostBack)

{

FillPatientInfo();

}

}

private void FillPatientInfo()

{

//bad approach for getting connection string.

string strcon = "data source=your sql server name ;initial catalog=your database name ;integrated security=sspi";

SqlConnection cn = new SqlConnection(strcon);

SqlCommand cmd = new SqlCommand("select * from patient", cn);

SqlDataAdapter da = new SqlDataAdapter();

da.SelectCommand = cmd;

da.Fill(ds);

gvPatients.DataSource = ds;

gvPatients.DataBind();

Session["dsPatients"] = ds;

//GridView1.DataSource = ds;

//GridView1.DataBind();

}

protected void gvPatients_RowEditing(object sender, GridViewEditEventArgs e)

{

gvPatients.EditIndex = e.NewEditIndex;

gvPatients.DataSource = (DataSet)Session["dsPatients"];

gvPatients.DataBind();

}

protected void gvPatients_RowDeleting(object sender, GridViewDeleteEventArgs e)

{

Label lblPatientID = (Label)gvPatients.Rows[e.RowIndex].FindControl("lblPatientID");

SqlConnection cn = new SqlConnection("data source=ADMIN-PC\\SQLEXPRESS;initial catalog=palletechnologies;integrated security=sspi");

SqlCommand cmd = new SqlCommand();

StringBuilder sb = new StringBuilder();

sb.Append("delete patient where patientid='" + lblPatientID.Text + "'");

cmd.CommandText = sb.ToString();

cmd.Connection = cn;

cn.Open();

cmd.ExecuteNonQuery();

cn.Close();

FillPatientInfo();

}

protected void gvPatients_RowUpdating(object sender, GridViewUpdateEventArgs e)

{

Label lblPatientID = (Label)gvPatients.Rows[e.RowIndex].FindControl("lblPatientID");

TextBox tbAge = (TextBox)gvPatients.Rows[e.RowIndex].FindControl("tbAge");

TextBox tbName = (TextBox)gvPatients.Rows[e.RowIndex].FindControl("tbName");

SqlConnection cn = new SqlConnection("data source=ADMIN-PC\\SQLEXPRESS;initial catalog=palletechnologies;integrated security=sspi");

SqlCommand cmd = new SqlCommand();

StringBuilder sb = new StringBuilder();

sb.Append("update patient set patientname='" + tbName .Text+ "',");

sb.Append("age='"+tbAge.Text+"' where patientid='"+lblPatientID.Text+"'");

cmd.CommandText = sb.ToString();

cmd.Connection = cn;

cn.Open();

cmd.ExecuteNonQuery();

cn.Close();

gvPatients.EditIndex = -1;

FillPatientInfo();

}

protected void gvPatients_SelectedIndexChanged(object sender, EventArgs e)

{

}

protected void gvPatients_RowCancel(object sender, GridViewCancelEditEventArgs e)

{

gvPatients.EditIndex = -1;

e.Cancel = true;

gvPatients.DataSource = (DataSet)Session["dsPatients"];

gvPatients.DataBind();

}

}

Patient table structure:

Create a patient table with PatientID,PatientName and Age columns.

How to set startup url in asp.net mvc

2014-04-10T00:22:00.001+05:30

1.Go to MVC web application property page and set Start Action Specific Page value equal to ControllerName/ActionMethodName ( refer below given screen shot )

What is an action method in MVC

2013-12-20T18:46:00.000+05:30

An action method in mvc is a method which can able to redirect user to a view ( an action method can optionally pass model data to a view for rendering views ui filled with model data ).
OR
An action method is a method which is returning ActionResult .

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About Global.asax in ASP.NET

2011-11-08T12:39:00.001+05:30

Global.asax is a file in asp.net
Global.asax file contains all the application level methods.like
1.Application_Start 2.Application_End 3.Session_Start 4.Session_End etc..
Note: When you compile your code for the first time your ASP.NET runtime creates a class corresponding to Global.asax file with the Class name global_asax. This class inherits from HTTP Application class.
You can see the automatically created class in the C:\Documents and Settings\User\My Documents\Visual Studio 2008\WebSites\ApplicationName\global.asax file.

Adding new Nodes to XML File in C#

2011-10-28T10:08:00.002+05:30

1.Create a Dummy xml file with the name Patients.xml in your solution explorer.
Ex:

<Patients>
<Patient type="IP">
<VistorNum>134</VistorNum>
<FName>Maha</FName>
<LName>Veer</LName>
<Age>89</Age>
<Sex>Male</Sex>
</Patient>
</Patients>

2.Create the UI to accept data from users.(Write the below code in .aspx page)
VisitorNum:<asp:TextBox ID="tbVstrNum" runat="server" ></asp:TextBox><br />
FName:<asp:TextBox ID="tbFName" runat="server" ></asp:TextBox><br />
LName:<asp:TextBox ID="tbLName" runat="server" ></asp:TextBox><br />
Age:<asp:TextBox ID="tbAge" runat="server" ></asp:TextBox><br />
Sex:<asp:TextBox ID="tbSex" runat="server" ></asp:TextBox><br />
<asp:Button ID="btnInsertPat" Text="AddPatient" runat="server"
onclick="btnInsertPat_Click" />
3.Write the below code in code behind's button click method.
protected void btnInsertPat_Click(object sender, EventArgs e)
{
XmlDocument doc = new XmlDocument();
doc.Load(Server.MapPath("Patients.xml"));
//Create a New patient node.
XmlNode nPatient=doc.CreateNode(XmlNodeType.Element,"Patient",null);
//Create visitornUm,FName,LName,Age,Sex nodes and add
//it to Patient Node
XmlElement eVistNum= doc.CreateElement("VistorNum");
eVistNum.InnerText = tbVstrNum.Text;
XmlElement eFName = doc.CreateElement("FName");
eFName.InnerText = tbFName.Text;
XmlElement eLName = doc.CreateElement("LName");
eLName.InnerText = tbLName.Text;
XmlElement eAge = doc.CreateElement("Age");
eAge.InnerText = tbAge.Text;
XmlElement eSex = doc.CreateElement("Sex");
eSex.InnerText = tbSex.Text;
nPatient.AppendChild(eVistNum);
nPatient.AppendChild(eFName);
nPatient.AppendChild(eLName);
nPatient.AppendChild(eAge);
nPatient.AppendChild(eSex);
//Get the Root Patients Node ref.
XmlNode root=doc.SelectSingleNode("Patients");
//Add New patient node to root patient node.
root.AppendChild(nPatient);
string sPath = Server.MapPath("Patients.xml");
doc.Save(sPath);
//elem.AppendChild(
}
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Opening My Computer Using ASP.NET

2011-09-09T13:54:00.000+05:30

Please use the HTML Input File Control for opening all the available Drives. Just Drag and drop the control
on to the .aspx page and check the result by clicking on the Browse Button.

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How to Encrypt Connection String

2011-08-28T17:09:00.000+05:30

For security reasons we need to encrypt the connection strings.
Encrypting and decrypting the connection string is very easy. Follow the Below steps to encrypt the Connection strings.
Encrypt Connection Strings:

Open visual studio command prompt.
type the given command aspnet_regiis -pef "connectionStrings" "YourApplicationFullPath where your web.config file is present" and then press Enter.

Decrypting Connection String:

aspnet_regiis -pdf "connectionStrings" "YourApplicationFullPath where your web.config file is present" and then press Enter.

Note : You need to use pef or pdf only if your website is created as a file system. If Your website is created as a IIS website then use pe or pd for encrypting or decrypting.

is and as operators in C#

2011-08-18T15:40:00.000+05:30

is Operator:

is operator Checks if an object is compatible with a given type
An is expression evaluates to true if the provided expression is non-null, and the provided object can be cast to the provided type without causing an exception to be thrown.

as Operator:

The as operator is used to perform conversions between compatible reference types
The as operator is like a cast operation. However, if the conversion is not possible, as returns null instead of raising an exception

Ex:

public class Exam

{

public string GetSubjectName()

{

return "C#";

}

public class UnitTest

{

public int GetTestNumber()

{

return 1;

}

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

{

protected void Page_Load(object sender, EventArgs e)

{

Exam e1 = new Exam();

}

public void Test(object o)

{

if (o is UnitTest)

{

UnitTest u = o as UnitTest;

u.GetTestNumber();

}

else if (o is Exam)

{

Exam e = o as Exam;

e.GetSubjectName();

}

Ternary Operators in C#

2011-08-18T08:13:00.000+05:30

Ternary operators can be use full when we have only one simple if else condition.
Ternary Operator Syntax:

condition ? first_expression : second_expression;

Ex:

public class TernaryEx
{
    public int GetBigNum(int a, int b)
    {
        return a > b ? a : b;
        //in the above syntax if a is greater than b
        //the above expression returns a else it returns b.
    }
}

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How to show XML Data in the Grid View

2011-07-17T20:23:00.000+05:30

Create a Page with the Name XMLSample.aspx
Write the Below controls in the .aspx source Page.
Create an xml file on the desktop with Name Students ( See example xml at the End)

<asp:GridView ID="gvList" runat="server">
</asp:GridView>
Path:
<asp:FileUpload ID="FileUpload1" runat="server" />
<asp:Button ID="btnAdd" runat="server" Text="Add" onclick="btnAdd_Click" />

Write the Below code in the Code behind file

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Xml;

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

{

protected void Page_Load(object sender, EventArgs e)

{

}

protected void btnAdd_Click(object sender, EventArgs e)

{

HttpPostedFile hpf=FileUpload1.PostedFile;

string fName=FileUpload1.PostedFile.FileName;

System.Data.DataSet ds = new System.Data.DataSet();

ds.ReadXml(fName);

gvList.DataSource = ds.Tables[0];

gvList.DataBind();

}

Note : Example Xml file.

<Students>
<Student>
<id>1312</id>
<name>123</name>
<age>123123</age>
</Student>
<Student>
<id>6</id>
<name>Ashoke</name>
<age>23</age>
</Student>
</Students>

Encrpt and Decrypt Connection String

2011-07-15T17:58:00.000+05:30

For Security reasons we need to encrypt the connection strings.

How to Encrypt a connection string:

Open visual studio command prompt.
Change your command prompt location and should point to your application physical drive
Assume your application Name is DataSet and is present in c:\Documents and Settings\Administrator\My Documents
type the below statements and then press enter to encrypt the connection
aspnet_regiis -pe "connectionStrings" -app "/DataSet"

How to Decrypt Connection:

Type the below command and press enter
aspnet_regiis -pd "connectionStrings" -app "/DataSet"

Note : See the below attached screen shot.

Sealed class

2011-07-09T17:27:00.000+05:30

Sealed class

It is complete class
It is allow creating an object
It is also called instance class
Inheritance is not possible for Sealed Class. Means No one can be able to inherit from a Sealed Class but sealed class can inherit from any other class (The Parent Class should not be Sealed Class).
Sealed class can never acts as a Parent Class
Static class is by default sealed class only.

Example for Sealed Class:

----------------------------------------------------

public sealed class ToyCalc

{

}

public class AdvancedToyCalc : ToyCalc

{

}

Note 1: The above Code is wrong since a sealed class can never act as a Base or Parent Class.

Note 2: But ToyCalc class can inherit from other classes ex.

Ex: public sealed class ToyCalc: Toy

The Toy Class should not be a Static Class or SealedClass.

Abstract Class

2011-07-09T17:11:00.000+05:30

Abstract Class:

When a class is not providing full functionality it recommended to declare that class as an Abstract class.
Method with out body is called an abstract method.
Ex: public abstract void GetArea ();
When class contain at least one abstract method then that class must be declared as abstract class.
All the abstract method must be overridden in the derived class.
We cant create object for Abstract class.

Ex :

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

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

{

protected void Page_Load(object sender, EventArgs e)

{

Circle c = new Circle ();

c.print();

Response.Write(c.findarea()+" ");

Response.Write("
"+c.print());

}

public abstract class Shape

{

private int x = 10;

private int y = 20;

public int print()

{

return (x + y);

}

public abstract double findarea();

}

public class Circle : Shape

{

private int r = 10;

public override double findarea()

{

double a = 3.14 * r * r;

return (a);

}

Important JavaScript Methods

2011-06-08T22:24:00.000+05:30

The below JavaScript methods are very much useful while writing JavaScript Code.
Note: Below Questions are Frequently asked in .NET Interviews
1.document.getElementById("ControlID");
2.document.getElementByName("Control Name");

Dom Properties:

the below properties are the freequently used properties while writing JavaScript Code.

z.innerHTML - the text value of z
z.nodeName - the name of z
z.nodeValue - the value of z
z.parentNode - the parent node of z
z.childNodes - the child nodes of z
z.attributes - the attributes nodes of z

Note: z Represents HTMLElement ( ex. Text Box or Radio Button )

Why .NET is better than Java

2011-05-18T18:09:00.000+05:30

There are couple things we need to understand before comparing Java and .NET.

1.Usually softwares are developed to automate any business and to reduce human intervention.
2.Let us Say Palle Technologies wanted to develop a software for XYZ hospital. Since XYZ hospital wanted to automate the Registration,Admission,Scheduling etc process and they decided to develop a software which makes their daily work faster and increases Revenue.
3.They gave contract of developing an application to PalleTechnologiies and asked to come with feasible choice of softwares and they gave us 6 months time for development for what ever the technology they choose.
4.We analysed the requirement and estimated development and maintainence effort for Both Java and .NET
5. We saw significant notable differences between JAVA and .NET
Note: Assumed Application Life time = 15 years.
Look at the Estimated Costs Required for creating the application for XYZ company.
Estimation for Java Application :
Java Total Resources Required for Development (6 months)= 6 resources
Cost of Each Resource= 6* 20000 INR/Month
Total Resources Cost During Development=720000 INR
Note: We assumed XYZ company is going to use this software for 15 years
Cost of Maintaining the Application for 1 year =3*20000 INR/Person/Month*12 Months=720000
Cost of Maintaining the Application for 15 years=10800000 INR.
Cost of Softwares and Servers = 60000 INR.
Total Cost=11580000 INR.
Estimation for .NET Application :

.NET Total Resources Required for Development (6 months)= 5 resources

Cost of Each Resource= 5* 20000 INR/Month

Total Resources Cost During Development=700000 INR

Note: We assumed XYZ company is going to use this software for 15 years

Cost of Maintaining the Application for 1 year with 2 Resources=2*20000 INR/Person/Month*12 Months=480000

Cost of Maintaining the Application for 15 years=7200000 INR.

Cost of Softwares and Servers = 100000 INR.

Total Cost=8000000 INR.

We found significant difference of almost 30 lakhs of rupees savings to XYZ company if They Choose .NET.

AutoEventWireUp

2011-04-06T07:57:00.000+05:30

AutoEventWireUp attribute in asp.net is used to call the Page_Load and Page_InIt methods automatically
by setting AutoEventWireUp=true;
By default AutoEventWireup set to true in machine.config and hence at the page level it is set to false
If you set AutoEventWireUp=true at page level then Page_Load and Page_InIt will be executed twice.

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User Control assignment ( Change Button color from User Control Text Box Value)

2011-04-06T07:49:00.000+05:30

1.Create User Control with name Enquiry . Drag and drop Text box control on the Enquiry.ascx
   set text box id="tbColorName".
2.Create a property in the Enquiry.ascx.cs as shown below.
   protected void Page_Load(object sender, EventArgs e)
   {

   }
   private string _color;

   public string Color
   {
   get { return _color; }
   set { _color = value; }
   }
3.Create a Page with Name UserControlSample.aspx and do below given activities

Drag and drop a button on the aspx page and set id="btnSubmit" Text="Submit"
Drag and drop the User Control on to the surface of the aspx page. Set UserControl id="Enquiry1".

4.Write the below code in the UserControlSample.aspx.cs

protected void btnSubmit_Click(object sender, EventArgs e)

{

foreach (var c in Enquiry1.Controls)

{

Type t=c.GetType();

if (t.Name=="TextBox")

{

Enquiry1.Color = ((TextBox)c).Text;

}

btnSubmit.BackColor = System.Drawing.Color.FromName(Enquiry1.Color);

}

5.Execute the application by pressing F5.

JavaScript Validations

2011-03-31T23:25:00.000+05:30

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

<!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>Registration Form</title>
<script language="javascript" type="text/javascript">
function fnValidate()
{
//FName Validation.
fnValidateFirstName();
//LName Validation
fnValidateLastName();
//Mobile validation
fnValidateMobileNumber();
//PEmail validation
fnValidatePrimaryEmail();
//SEmail Validation
fnValidateSecondaryEmail();
//Counttry Validation
fnValidateCountries();
}
function fnValidateSecondaryEmail()
{
var semail=document.getElementById("txtsemail").value;
var semailregex=/^(?:\w+\.?)*\w+@(?:\w+\.)+\w+$/;
if(!semail.match(semailregex))
{
alert("enter valid emailid");
}
}
function fnValidatePrimaryEmail()
{
var pemailno=document.getElementById("txtPemail").value;
if(pemailno=="")
{
alert("email id is mandatory");
}
var pemailregex=/^(?:\w+\.?)*\w+@(?:\w+\.)+\w+$/;
if(!pemailno.match(pemailregex))
{
alert("enter valid emailid");
}
}
function fnValidateMobileNumber()
{
var mobile=document.getElementById("txtMobile").value;
if(mobile=="")
{
alert("Mobile number is mandatory");
}
var mno= /^((\+)?(\d{2}[-]))?(\d{10}){1}?$/;
if(!mobile.match(mno))
{
alert("1.Mobile Number should Have Only Digits .\n2.Mobile Number should contain 10 digits");
return false;
}
else
{
return true;
}
}
function fnValidateLastName()
{
var lname=document.getElementById("txtlname").value;
var alphaExp= /^[a-zA-Z]+$/;
if(!lname.match(alphaExp))
{
alert("Last name should have only alphabets");
return false;
}
else
{
return true;
}
}
function fnValidateFirstName()
{
var fname=document.getElementById("txtfname").value;
if(fname=="")
{
alert("First Name Cannot be Blank.");
return false;
}
else
{
var alphaExp = /^[a-zA-Z]+$/;

if(!fname.match(alphaExp))
{
alert("First Name should contain Only Alphabets.");
return false;
}
return true;
}
}
function fnValidateCountries()
{
var index=document.getElementById("ddlCountry").selectedIndex;
alert(index);
if(index==0)
{
alert("Please Select a Country.");
return false;
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<table width="100%">
<tr>
<td width="15%"></td>
<td width="70%">
<table>
<tr>
<td align="right">FirstName:</td>
<td><asp:TextBox ID="txtfname" runat="server" /></td>
<td align="right">Mobile:</td>
<td><asp:TextBox ID="txtMobile" runat="server" /></td>
</tr>
<tr>
<td align="right">LastName:</td>
<td><asp:TextBox ID="txtlname" runat="server" /></td>
<td align="right">Phone:</td>
<td><asp:TextBox Width="10%" ID="tbCountryCode" runat="server" />

<asp:TextBox Width="10%" ID="tbCityCode" runat="server" />

<asp:TextBox Width="29%" ID="tbPhone" runat="server" />
</td>
</tr>
<tr>
<td align="right">PrimaryMail: </td>
<td>
<asp:TextBox ID="txtPemail" runat="server" />
</td>
<td align="right">SecondaryMail:</td>
<td>
<asp:TextBox ID="txtsemail" runat="server" />
</td>
</tr>
<tr>
<td align="right">Address1:</td>
<td>
<asp:TextBox ID="txtaddress1" runat="server" TextMode="MultiLine" rows="5"/>
</td>
<td></td>
<td></td>
</tr>
<tr>
<td>Country:</td>
<td><asp:DropDownList ID="ddlCountry" runat="server"
width="80%"></asp:DropDownList></td>
<td></td>
<td><asp:Button ID="btnSubmit" runat="server" Text="Submit"
OnClientClick="return fnValidate()" /></td>
</tr>
</table>
</td>
<td width="15%"></td>
</tr>
</table>
</div>
</form>
</body>
</html>
Default.aspx Page End

Default.aspx.cs Page Start

using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Collections;

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

   private void FillCountries()
   {
   ArrayList alCountries = new ArrayList();
   alCountries.Add("India");
   alCountries.Add("Pakistan");
   alCountries.Add("Srilanka");
   alCountries.Add("Australia");
   ddlCountry.DataSource = alCountries;
   ddlCountry.DataBind();
   ddlCountry.Items.Insert(0, "--Select--");
   }
}

Default.aspx.cs Page End

What is JavaScript

2011-03-17T20:41:00.000+05:30

JavaScript is a Scripting language , The JavaScript(js) code will be executed by the JavaScript engine which comes with the Browser ( I.E,Opera,Mozilla etc..)
JavaScript is a loosely typed language and is called client side scripting language. Because the js code you have written in the .aspx pages will be sent back to client browser by the web server (IIS) and the JavaScript code will be executed by Browser hence we call this as Client side Script.
The Html and js code sent by IIS to browser will be executed by HTML parser and JavaScript engine which are present in the Browser software ( Browser like IE,Opera, Chrome all are softwares which contains code written in c-language etc..)
Note: For .net training institutes in Bangalore you can always visit http://techpalle.com/net-training-in-bangalore.html

Serialization and De-Serialization Example

2010-12-28T17:38:00.000+05:30

Create a webapplication(asp.net application ) using visual studio. Now create the below class
[Serializable]
    public class patient
    {
        private static patient p;
        private int _age;
        public int Age
        {
            get
            {
                return _age;
            }
            set
            {
                _age = value;
            }
        }
        private patient()
        {

        }
        public static patient getPatientObject()
        {
            if (p == null)
            {
                p = new patient(); return p;
            }
            else
            {
                return p;
            }
        }
        public static void SerializeToXML()
        {
            //Note: XmlSerializer is a Protected class
            patient pat = new patient();
            XmlSerializer serializer = new XmlSerializer(typeof(patient));
            TextWriter textWriter = new StreamWriter(@"C:\serializedpatient.xml");
            serializer.Serialize(textWriter, pat);
            textWriter.Close();
        }
        public static patient DeserializeFromXml()
        {
            TextReader tr=new StreamReader(@"c:\serializedpatient.xml");
            XmlSerializer serializer = new XmlSerializer(typeof(patient));
            patient p=(patient)serializer.Deserialize(tr);
            return p;
        }
    }
Next Steps: 1. Now Create a .aspx page with name SerializationSample.aspx
2.Create 2 Buttons with name Serialize( button id=btnSerialize) De-Serialize ( button id=btnDeserialize)
3.Create handlers for these two buttons. Call the methods "patient.SerializeToXML(); " and "patient.DeserializeFromXml();" from the clickeventhandler methods btnSerialize_click,btnDeserialize_click respectively.
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what is Serialization and when to do it?

2010-12-23T18:04:00.000+05:30

Student: What is Serialization?
TechPalle: Serialization is the process of converting an object into a stream. stream can be xml stream or it can be a byte stream.
Student: Why should i do Serialization?
TechPalle: Serialization is required many times in Real time programming.
Below are the examples of when to use Serialization.
Ex 1: In the 3-tier architecture let us say we have BAL,DAL and UI layer. Now assume these projects deployed in three different machines. now i want to get an object of some class from one tier to other tier or application in another computer. So if you want to send objects from one computer to another , you cannot transfer the object in its original form . But you need to convert the object into some form of stream and then send the stream to another computer. Now after receiving the stream then get the object back by DE-serializing the object back from the stream. This is the common situation where you have to do Serialization and De-Serialization. See complete example of Serialization and De serialization in the next article.