ASP.Net Web Developement Solutions for C# and VB.Net

Get list of all currently running procedure in SQL Server

noreply@blogger.com (Unknown) — Fri, 29 Apr 2011 07:41:00 +0000

Sometimes it is a need to find out which stored procedure are running on the SQL Server.Below SQL query will provide the list of stored procedure which are currently running on the server.

SELECT OBJECT_NAME(ObjectID) as ObjectName,
  st.Text, 
  DB_NAME(database_ID) as dbname,
  Blocking_session_ID as BlockingSessionID,  
  *
FROM sys.dm_exec_requests r
CROSS APPLY sys.dm_exec_sql_text(sql_handle) AS st

ASP.NET Coding Standards

noreply@blogger.com (Unknown) — Thu, 09 Sep 2010 13:11:00 +0000

I found a great post, which focuses on ASP.NET Coding Standards. These standards should be considered while working with ASP.NET application.

You can read the article here.

Validate Blank Subject line for Outlook 2007

noreply@blogger.com (Unknown) — Wed, 23 Jun 2010 11:25:00 +0000

Currently, in the professional world, Outlook is most popularly used as the email client. The subject line is a very important part of any email. A good subject line can attract the attention of the email reader. How many times has it happened to you that you have sent an email through Outlook without a subject line? After clicking the Send button, you realize that you have made a mistake. Are you forgetting to include the subject line in emails? Outlook does not validate for an empty subject line.

Solution

We'll follow these steps to validate an empty subject line for Outlook 2007.

1. Go to Tools -> Macro -> Visual Basic Editor. Or, directly press Alt + F11.

2. The Visual Basic editor window gets opened.
3. On the left pane, you will see Microsoft Outlook Objects or Project1, expand this. Now, you will see the ThisOutLookSession entry.

4. Double click on ThisOutLookSession. It will open up a code pane.
5. Copy and paste the following code in the code pane:

Private Sub Application_ItemSend(ByVal Item As Object, Cancel As Boolean)
   Dim strSubject As String
   strSubject = Item.Subject
   If Len(Trim(strSubject)) = 0 Then
       Prompt$ = "Subject is Empty. Are you sure you want to send the Mail?"
      If MsgBox(Prompt$, vbYesNo + vbQuestion + _
            vbMsgBoxSetForeground, _
            "Check for Subject") = vbNo Then
        Cancel = True
      End If
  End If
End Sub

Now, just save the project.

There is one more setting you need to do, and that is to enable the macro. Go to Tools->Macro->Security. A dialog window gets opened. Select Warning for all macro options.

That's it.. You are good to go now.

Close your Outlook and open it again. You will be notified about a security concern. See the image below:

Click on Enable Macros.

Now, try to send an mail with an empty subject line. Enjoy....

Enjoy,
Virendra Dugar

Access ViewState between Pages

noreply@blogger.com (Unknown) — Mon, 21 Jun 2010 06:13:00 +0000

Before I start this article, let me ask you something. Is it possible to access the ViewState variable of one page on another page? I don't know what your answer is. Well, frankly speaking, my answer was also "NO" before writing this article as it is said that ViewState is page specific.

ViewState is a very misunderstood animal. It is said that ViewState is Page specific; that means, it is available only on the same page on which it was created. Once you redirect to another page, the previous page's viewstate is no longer accessible. But that is not true.

Demo

Yes, we can access the viewstate variables across pages. This is only possible if Cross Page Posting or Server.transfer is used to redirect the user to other page. If Response.redirect is used, then ViewState cannot be accessed across pages.

Before you continue reading this article, please read these articles on Cross Page Posting and Server.transfer.

Ok, so all set now... I will demonstrate this using the demo created by me. You can download the demo from the link at the top of this article.

I have created two *.aspx pages named:

ViewStateContainer.aspx: This page sets the ViewState variable and transfers the user to another page using Server.transfer.
AccessViewState.aspx: This page accesses the ViewState variable of ViewStateContainer.aspx page.

This is the code of ViewStateContainer.aspx page:

public partial class ViewStateContainer : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        ViewState["Page1"] = "Page1 ViewState";
        Server.Transfer("AccessViewState.aspx");
    }

    public StateBag ReturnViewState()
    {
        return ViewState;
    }
}

As you can see, I have set a ViewState variable in Page Load and transfer the user to AccessViewState.aspx page using the Server.transfer() method.

This page also contains a method ReturnViewState() which actually returns the ViewState of this page to the calling function. The return type of the method is StateBag class.

StateBag class: This class is the primary storage mechanism for all HTML and Web server controls. It stores attribute/value pairs as strings associated with the control. It tracks changes to these attributes only after the OnInit method is executed for a page request, and saves the changes to the page's or control's viewstate.

Now let's take look at AccessViewState.aspx Page code:

public partial class AccessViewState : System.Web.UI.Page
{
    private StateBag PreviousPageViewState
    {
        get
        {
            StateBag returnValue = null;
            if (PreviousPage != null)
            {
                Object objPreviousPage = (Object)PreviousPage;
                MethodInfo objMethod = objPreviousPage.GetType().GetMethod
      ("ReturnViewState");
                return (StateBag)objMethod.Invoke(objPreviousPage, null);
            }
            return returnValue;
        }
    }

    protected void Page_Load(object sender, EventArgs e)
    {
        if (PreviousPage != null)
        {
            if (PreviousPageViewState != null)
            {
                Label1.Text = PreviousPageViewState["Page1"].ToString();
            }
        }
    }
}

Whenever we use Server.transfer or Cross Page Posting, We can get the previous page object via PreviousPage property. Using Previous Page, we can find the controls of the previous page. For example, one can access Label control placed in ViewStateContainer Page in current Page.

Looking at the code, I have created a PreviousPageViewState property in this page, which returns the previous page's ViewState. It first checks whether PreviousPage is null or not, if it's not null, then it creates an object of the previous page. Now using Reflection, we can invoke the method of the previous class. Using MethodInfo class, I have invoked the ReturnViewState() method of ViewStateContainer Page.

In Page_Load event, I am able to access the ViewState variable of ViewStateContainer Page. You can access all the viewstate variables set in ViewStateContainer Page.

Enjoy,
Virendra Dugar

Check/Uncheck All Checkboxes with JQuery

noreply@blogger.com (Unknown) — Sat, 22 May 2010 09:53:00 +0000

This particular article is about a pretty common functionality which I think most of the software engineers face in their projects. Even I came across the same situation many times. Previously I used to achieve the functionality via JavaScript, which really worked flawlessly. But as a software engineer, I think one should always adapt the new technology. So, this time I tried to achieve the same via JQuery as its booming now and one need to upgrade himself. So what functionality are we talking about? See below given image.

Okay. So you must have got the idea about the functionality. Yes, you guessed it right. It’s about selecting all the items of checkbox list, when select all is checked. You can find thousands of solution using Jquery when you google it. Then why you are here. Well, in fact I googled a lot but didn’t even come across to a single article which solves my purpose. Let me explain the requirement of the functionality here.

When “Select All” checkbox is checked, it must change the status of all the items of the checkbox list as per “Select All” status. For e.g., if “Select All” is true then all the items of the checkbox list must be set to true or vice versa. See Image 2.

Image 2
Assume, “Select All” is true and all the items of the checkbox list are also true. But when I uncheck any item of checkbox list, it must also uncheck the select all button. See Image 3.

Image 3
Assume, “Select All” is unchecked. And one of the items in the checkbox list is also unchecked. But now when I check the checkbox list item, then “Select All” must be checked. As all the items in the checkbox list are checked.

So let’s go directly to the code.

Prerequisite: I assume that you know the basics of JQuery. Read this article for information on Introduction to JQuery.

<table cellpadding="2" cellspacing="2" width="50%">
<tr>
                <th align="left" style="font-family:Arial;">
                    <h3>
                        Checkbox Select All Demo using JQuery</h3>
                </th>
            </tr>
            <tr>
                <td>
                    &nbsp;<asp:CheckBox ID="chkSelectAll" runat="server" Text="Select All" Font-Size="9pt"
                        Font-Names="Arial" />
                </td>
            </tr>
            <tr>
                <td>
                    <asp:CheckBoxList ID="chkItems" runat="server" Width="200px" Font-Size="9pt" Font-Names="Arial"
                        BorderStyle="Solid" BorderColor="Black" BorderWidth="1px">
                    </asp:CheckBoxList>
                </td>
            </tr>
        </table>

Well, I have placed a checkbox “Select All” with ID “chkSelectAll” and a checkbox list with ID “chkItems”.

<script type="text/javascript">
    $(document).ready(function() {
        $("#<%=chkSelectAll.ClientID %>").click(function() {
                $("#<%= chkItems.ClientID %> input:checkbox").attr('checked',this.checked);
        });
        
        $("#<%=chkItems.ClientID %> input:checkbox").click(function(){
            if($("#<%= chkSelectAll.ClientID %>").attr('checked') == true && this.checked == false)
                $("#<%= chkSelectAll.ClientID %>").attr('checked',false);
                
             if(this.checked == true)
                CheckSelectAll();
        });
        
        function CheckSelectAll()
        {
            var flag = true;
            $("#<%=chkItems.ClientID %> input:checkbox").each(function() {
                if(this.checked == false)
                    flag = false;
            });
              $("#<%= chkSelectAll.ClientID %>").attr('checked',flag);
        }
        
    });
    
    </script>

Well above given code solves my purpose. Let’s go through the code function by function.

$("#<%=chkSelectAll.ClientID %>").click(function() {
                $("#<%= chkItems.ClientID %> input:checkbox").attr('checked',this.checked);
        });

This code binds click event to “Select All” checkbox. It will search for all the checkbox inside the chkItems (as checkbox list, when rendered becomes a table. See the view source.) and set the checked attribute to the value of “Select All” checkbox. 2 Lines of code can serve your purpose. That’s why I love JQuery.

Next function binds the click event to every checkbox of checkbox list.

$("#<%=chkItems.ClientID %> input:checkbox").click(function(){

Inside the function, it first check for the status of “Select All”. If it’s true and the clicked checkbox is unchecked (see Image 3), then it will uncheck the “Select All” checkbox.

if($("#<%= chkSelectAll.ClientID %>").attr('checked') == true && this.checked == false)
                $("#<%= chkSelectAll.ClientID %>").attr('checked',false);

Next task is, if the clicked checkbox item status is checked, then we need to check the status of all the items of checkbox list and if every item is checked, then we must check the “Select All” checkbox.

if(this.checked == true)
                CheckSelectAll();

This will call a function “CheckSelectAll”. This function iterates thorugh the checkbox list and finds all the items are checked or not. If yes, then it sets the status of “Select All” checkbox accordingly.

function CheckSelectAll(){
            var flag = true;
            $("#<%=chkItems.ClientID %> input:checkbox").each(function() {
                if(this.checked == false)
                    flag = false;
            });
              $("#<%= chkSelectAll.ClientID %>").attr('checked',flag);
        }

each() method of JQuery will perfomes the iteration for specified item.

That’s it. Hope this will help you in your work.

Enjoy,
Virendra

15 New Features of jQuery 1.4

noreply@blogger.com (Unknown) — Wed, 20 Jan 2010 09:39:00 +0000

jQuery 1.4 was recently released. There are many new features, enhancements and performance improvements included in 1.4!

You can download jQuery 1.4 right now, here:http://code.jquery.com/jquery-1.4.js

Check this article to know 15 New Features of JQuery 1.4

Enjoy..

Set Page Position after asyncPostback

noreply@blogger.com (Unknown) — Sun, 03 Jan 2010 08:54:00 +0000

I will start this article, with one of the problem which I faced recently.

BackGround

I was working with a page. The page is divided into two parts.

1. Add/Update/Delete (I call it Area 1)

2. Listing of records (I call it Area 2)

I have used Repeater control with no paging (Though the records are more but my client hates paging. :) ). Above the repeater control, there were some textbox, dropdowns, checkbox, listbox etc. were placed used for add/update operations. There is a link button in the repeater control for every row, which when clicked opens the records in update mode. It fills all the control with data placed on Area 1 . Everything is placed in an UpdatePanel.

Problem

There were more than 10000 records listed in the repeater. When I click the very last record for editing, asynchronous postback happens and data is loaded for editing in Area 1 . But the problem was with the page position. I was not able to see the control's of Part1, as page was maintaining it's scroll position after async postback. This is what I don't want. As it's not at all user friendly. End-User will never come to know that record has been opened in edit mode. I set the "MaintainScrollPositionOnPostback" property to false but it was not working because of AJAX. Somehow, I want page position to be set to (0,0) so that I can see Area 1 controls.

Solution

The solution was to set Page position back to 0,0, at the end of ajax request. Here is what I did. See below code.

  
<script type="text/javascript">
var prm = Sys.WebForms.PageRequestManager.getInstance();
prm.add_endRequest(EndRequestHandler);
function EndRequestHandler(sender, args) {
    window.scroll(0,0);
}
</script>

Javascript provides a function scroll() which basically scrolls page position to the specified value. It takes two arguments Top and left. I passed it 0,0 and it worked for me.

Enjoy..

Visual Studio List of Some ShortCut Keys

noreply@blogger.com (Virendra) — Thu, 31 Dec 2009 11:46:00 +0000

Use these shortcut keys to save your time while working with Visual Studio.

Shortcut	Description
F3	Finds the next occurrence of the previous search text.
F5	Start debugging
F7	Jump to code behind file from .aspx files
F8	Moves the cursor to the next item, such as a task in the Task List window or a search match in the Find Results window. Each time you press F8, you move to the next item in the list.
F9	Toggle breakpoint
F12	Go to definition of identifier under cursor
Ctrl+F5	Start without debugging
Ctrl+F2	Jump to the Navigation Bar (hit TAB to get to the right side)
Ctrl+F3	Find word under cursor
Ctrl+TAB	Toggle between windows in Visual Studio
Ctrl+I	Incremental search (this is way better than Ctrl+F)
Ctrl+J	Force IntelliSense for field members
Ctrl+C (with nothing selected)	Copy whole line
Ctrl+Enter	Open line above line cursor is on
Ctrl-X or Ctrl-L (with nothing selected)	Cut whole line
Ctrl+]	Bounce cursor between matching parentheses/brackets/braces
Ctrl+PageDown	Toggle between Design and Source views in .aspx files
Alt+W, L	Close all windows
Ctrl+K, Ctrl+C	Comment out selection
Ctrl+K, Ctrl+U	Uncomment selection
Ctrl+K, Ctrl+D	Format document
Ctrl+K, Ctrl+X	Insert snippet (or just type in the snippet name and hit TAB, TAB)
Ctrl+K, Ctrl+S	Surround selected lines with snippet
Ctrl+K, Ctrl+K	Toggle bookmark on/off
Ctrl+K, Ctrl+P	Jump to previous bookmark
Ctrl+K, Ctrl+N	Jump to next bookmark
Ctrl+M, Ctrl+M	Open/close current fold
Ctrl+M, Ctrl+O	Fold all methods
Ctrl+R, Ctrl+R	Enables or disables word wrap in an editor.
Ctrl+Shift+B	Build solution
Ctrl+Shift+C	Displays the Class View window
Ctrl+Shift+Enter	Open line below line cursor is on
Ctrl+Shift+F	Global Search
Ctrl+Shift+F9	Delete all breakpoints
Ctrl+Alt+A	Displays the Command window, which allows you to type commands that manipulate the IDE.
Ctrl+Alt+I	Displays the Immediate window, where you can evaluate expressions and execute individual commands.
Ctrl+Alt+K	Displays the Task List window where you customize, categorize and manage tasks, comments, shortcuts, warnings and error messages.
Ctrl+Alt+L	Open the Solution Explorer (to find your file after you just closed them all)
Ctrl+Alt+T	View Document Outline
Ctrl+Alt+0	Displays the Output window to view status messages at run time
Ctrl+Alt+R	Open browser within VS.NET
Ctrl+Alt+U	Displays the Modules window, which allows you to view the .dll or .exe files used by the program. In multiprocess debugging, you can right-click and select Show Modules for all Programs.
Ctrl+Alt+X	Open Toolbox
Shift+Alt+Enter	View editor in full screen mode

Introduction to Jquery

noreply@blogger.com (Virendra) — Mon, 30 Nov 2009 16:51:00 +0000

Introduction

JQuery is a Java script libarary/ Java Script framework that simplifies the interaction process or access process of traversing in HTML document. It provides methods to make animations, add ajax interaction to the page, provides an easy way to apply CSS to any items and provides an easy mechanism for binding and unbinding events. Huge code written using Java script can easily replaced by few lines of code in JQuery.

History of JQuery

Initially it’s was released in January 2006 but the very first stable version of JQuery 1.0 was released in August 2006. This version had support for CSS, events and Ajax. After that many version of JQuery were released but the latest version is JQuery 1.3.2. You can download this from JQuery website.

What can be done using JQuery

1. Allows to access elements in the document

If one need to access the DOM tree without any JavaScript libarary, one has to write many lines of code. JQuery provides a selector mechanism to access any part of DOM.

2. Easily apply CSS

As it’s known that CSS is the most powerful and mostly used for good appreance of any webpage. JQuery provides CSS Selectors which allows to change the CSS classes or individual style for any portion of the document. This can be done even after the page is rendered.

3. Make Animation

For better user experience, animation can do the job for you. JQuery provides many methods to perform animations like show,hide, fade, wipe, start, stop etc. Doing all this with JQuery is fun as No huge lines of code, no complex logic.

4. Ajax Interaction

In today’s world, Ajax is one of the most popular technology used in almost every website for better user experience. Jquery provides support for ajax also which allows to access server side event without refreshing the web page.

5. API to change document’s content

JQuery provides API (Application Program Interface) which allows to change the content of the document. Changing Text, inserting images, ordering of list can be done with few keystrokes with JQuery API. Entire structure of HTML can be rewritten or extended.

6. Event handling

Any technology is a failure if it cannot responsed to the user when any event takes place. Jquerys’s event handling is one the decent feature. It quickly responsed to any event such as user clicking a button.

Demo

To start with JQuery, first download the Jquery from it’s official website (http://JQuery.com). Make sure you download the latest copy of the JQuery.

`1`	`<script src="Script/jquery.js"` `type="text/javascript"></script>`

I have copied the jquery.js and placed it in script directory of the project. In this demo, I am going to show you how easily you can change the CSS and do animation.

Let’s first take a look at HTML

1<h2>
2History of JQuery</h2>
3<div id="content">
4Initially it's was released in January 2006 but the very first stable version of JQuery 1.0 was released in August 2006. This version had support for CSS,events and Ajax. After that many version of JQuery were released but the latest version is JQuery 1.3.2. You can download this from JQuery website.
5</div>

As you can see, I have placed a div tag with it’s ID set to content. Now, I will show you how you can find the div and apply CSS to it using JQuery.

01<style type="text/css">
02    .ApplyColor
03        {
04            background-color: Gray;
05            font-family: Arial;
06            font-size: 10pt;
07            color: White;
08        }
09    h2
10        {
11            font-size: 20pt;
12        }
13</style>
14 
15<script type="text/javascript" language="javascript">
16 
17    $(document).ready(function() {
18        $('#content').addClass('ApplyColor');
19    });
20</script>

.ready() is a jQuery event handler. This particular event handler will execute when the document is ready to be accessed and scripts have completed loading. A .ready() handler can be placed anywhere on the page and you can even have multiple ready handlers in the page.

Now, if you run this page, you will see the div with content id is having gray background and white color foreground.

Let’s go to the animation part with JQuery.

Place a button and some text in Paragraph tag. Using JQuery, I will add a click event handler.

1<asp:Button ID="btnShow" runat="server" Text="Show" />
2<p style="display: none;background-color:Red">
3    Hello
4</p>

Now add this Jquery code to document.ready event

01<script type="text/javascript" language="javascript">
02 
03    $(document).ready(function() {
04        $('#btnShow').click(function() {
05              $("p").show("");
06              return false;
07        });
08    });
09 
10</script>

Above code will find the btnshow and add a click event handler to it. When the button is click then Jquery will find the p tag and make a call to show function which will display the content of the p tag on the screen.

Like wise there are many more functions for animation. You can find the whole list over here.

Reference
http://jquery.com/

Conclusion

This is just an overview of starting with Jquery. Many more complex things can be done via jquery with ease. Go to this main page of Jqueryand learn as much as you can.

Happy Programming…

Virendra Dugar

Blogged with the Flock Browser

Difference between C# and VB.NET

noreply@blogger.com (Virendra) — Mon, 30 Nov 2009 16:41:00 +0000

This question is asked almost in every interview, if you have worked with both the language. There are syntax difference, keyword difference in both the language. But the interviewer is not looking for such answers. One need to explain the functional difference between both the languages.

Here are some key difference in C# and VB.NET other than syntax differences.

In C#, using keyword is used to release unmanaged resources. (Not available in VB.NET)
Optional parameter is supported in VB.NET. (Not available in C# 3.0 or below version).
Structure and unstructured error handling (On Error GoTo) is supported in VB.NET. (Unstructured error handling is not supported in C#).
Event gets bind automatically in VB.Net.
VB.NET is not case sensitive where C# is.
Shadowing: – This is a VB.Net Concept by which you can provide a new implementation for the base class member without overriding the member. You can shadow a base class member in the derived class by using the keyword “Shadows”. The method signature, access level and return type of the shadowed member can be completely different than the base class member.

Hiding: – This is a C# Concept by which you can provide a new implementation for the base class member without overriding the member. You can hide a base class member in the derived class by using the keyword “new”. The method signature, access level and return type of the hidden member has to be same as the base class member.
Comparing the two:-
1) The access level, signature and the return type can only be changed when you are shadowing with VB.NET. Hiding and overriding demands these parameters as same.
2) The difference lies when you call the derived class object with a base class variable. In class of overriding although you assign a derived class object to base class variable it will call the derived class function. In case of shadowing or hiding the base class function will be called.
Visual Basic .NET can also force parameters to be passed by value, regardless of how they are declared, by enclosing the parameters in extra parentheses. There is no way to achieve this thing in C#.
For Example:
1 Dim y As Integer = 5
2 Dim z As Integer
3 z = Add(y) //This will set both Y and Z to 6.
4 z = Add((y)) //This will set Z to 6 but Value of Y will not be change, as we have included extra parenthese while calling.
The Add function:
1 Public Function Add(ByRef x As Integer) As Integer
2 x = x + 1
3 Return x
4 End Function

I know this is not a complete list, so if you know any other difference kindly post your comments.

Enjoy..

AsyncFileUpload Control - New Control in Ajax Control ToolKit

noreply@blogger.com (Virendra) — Sat, 28 Nov 2009 05:59:00 +0000

Ajax Control Toolkit is not new for every dotnet developer. A new version of the AJAX Control Toolkit is now available for download from the CodePlex website.

This new version of the AJAX Control Toolkit contains two new controls:

SeaDragon Java Script Code (SJC) - The SJC control allows you SeaDragon scripts are used to display an image, and to zoom in and out of that image using mouse button keys without resizing the window. I saw the demo and it's really cool control.

AsyncFileUpload - Finally, we have a control which uploads file asynchronously. This new control enables you to perform file uploads without doing a postback. The control displays a throbber image during upload and raises client and server events when the upload is complete. Check the live demo here.
In this article, we are going to take a look at AsyncFileUpload control.

Note: This control will only work with .NET 3.5 or higher version.

AsyncFileUpload Control Features

As we know, File Upload control of ASP.NET does not work with in update panel. If we want to place it in update panel, then also postback trigger is required to upload the file. This cool control allows you to upload the file in asynchronous manner. Below are few key points about this control:

It works within the Update Panel.
Uploads the file without any postback.
Provides Client Side and Server side events.
Different coloring options for showing file upload. As for example, it shows green color if upload is successful, otherwise it shows red if there is unsuccessful upload.
You can show the loading image while file uploading is in progress.

But it also comes with certain disadvantages.

When I was working with the control, once the file is uploaded there is no way to clear the content of file upload control.
I went into the source code of this control and noticed that the control stores the file in Session. It never clears the session, which means every time to navigate back to the page it loads the last file uploaded into the text box.
There is no way to cancel the upload.
There is no way to monitor the progress (How much % is completed) of uploading.
Uploading starts as soon as you select the file. It stores the files in the session.

Besides, these disadvantages control looks good.

Now let's go thru some of the properties of this control.

Properties and Methods

Some Available Properties

CompleteBackColor : This Property set the background color of the control on successful upload. Default Value is "Lime".
ErrorBackColor : This Property set the background color of the control on unsuccessful upload. Default Value is "Red".
UploadingBackColor : This Property set the background color of the control when file uploading is in progress.
UploaderStyle : There are two options available for styling of the control. Traditional and modern. Default is "Traditional".
ThrobberID : ID of control that is shown while the file is uploading. It will be used to display the loading/in progress image.
HasFile : Returns a bool value which indicates control has a file or not.

Available Events:

OnClientUploadError : This is a client side event. If there is an unsuccessful upload then specified JavaScript function will be executed.

OnClientUploadStarted : This is also a client side event. Specified JavaScript function will be called when the uploading start. This event will be called before uploading and once this function is executed, uploading will start.

OnClientUploadComplete : This is also a client side event. If there is successful upload then specified JavaScript function will be executed.

onuploadedcomplete : This is a server side event which will be executed once the uploading is complete. One thing to notice over here is, as soon as you select the file, uploading starts but it remains in session. It is not stored on any physical location. In this event, we can specify the path and save the file into physical location.Things will be clear once we go thru the code.

Available Methods:

SaveAs() : This method saves the file on specified path.

Demo

Let’s create a new website and add reference of newly downloaded AjaxControl ToolKit dll. On default.aspx page, Place a script manager and register the ajax control toolkit dll.

Now let’s place the AsyncFileUpload control.

<cc1:AsyncFileUpload ID="AsyncFileUpload1" Width="400px" runat="server"

OnClientUploadError="uploadError" OnClientUploadStarted="StartUpload"

OnClientUploadComplete="UploadComplete"

CompleteBackColor="Lime" UploaderStyle="Modern"

ErrorBackColor="Red" ThrobberID="Throbber"

onuploadedcomplete="AsyncFileUpload1_UploadedComplete" UploadingBackColor="#66CCFF" />

We can place this within update panel or outside the update panel. As you can see, I have set the most of the properties and events which I have already explained above. Let’s place the Throbber control to show in progress image. It is not compulsory to have ThrobberID. If it is set then it will display the content of the control.

< asp:Label ID="Throbber" runat="server" Style="display: none">;

<img src="Images/indicator.gif" align="absmiddle" alt="loading" />;

</asp:Label>

I have also placed a label on the page, which shows the status of the uploading. Value of this control get’s updated via Client Side function.

< asp:Label ID="lblStatus" runat="server" Style="font-family: Arial; font-size: small;"> < /asp:Label>

Let’s place the JavaScript functions.

<script type="text/javascript" language="javascript">

function uploadError(sender,args)

{

document.getElementById('lblStatus').innerText = args.get_fileName(), "<span style='color:red;'>" + args.get_errorMessage() + "</span>";

}

function StartUpload(sender,args)

{

document.getElementById('lblStatus').innerText = 'Uploading Started.';

}

function UploadComplete(sender,args)

{

var filename = args.get_fileName();

var contentType = args.get_contentType();

var text = "Size of " + filename + " is " + args.get_length() + " bytes";

if (contentType.length > 0)

{

text += " and content type is '" + contentType + "'.";

}

document.getElementById('lblStatus').innerText = text;

}

</script>

The UploadComplete function displayes the file name, it’s size and content type on the screen.
Below is server side code of UploadedComplete event.

protected void AsyncFileUpload1_UploadedComplete(object sender, AjaxControlToolkit.AsyncFileUploadEventArgs e)
{
    System.Threading.Thread.Sleep(5000);
    if (AsyncFileUpload1.HasFile)
    {
 string strPath = MapPath("~/Uploads/") + Path.GetFileName(e.filename);
 AsyncFileUpload1.SaveAs(strPath);
    }
}

That’s it. We are good to go now. Now just run the application.
Conclusion
This is a cool control which some good user experience but as stated above I cannot find a way to clear the content of the control even if you refresh the page. Another thing that is quite annoying is as soon as you select any file, it starts uploading. Another lacking feature is it does not show the progress in percentages. Despite, few disadvantages, I found this control pretty useful. Hope to see some enhancement in this tool.
Enjoy..

Creating C# and VB.NET classes together using App_Code folder

noreply@blogger.com (Virendra) — Sat, 28 Nov 2009 05:33:00 +0000

In ASP.NET 2.0 one can mix web forms coded in C# and VB.NET together in a single web site. This works great for web forms. However if you want to code classes from App_Code folder in different languages? Such mixing of classes coded in different languages is not allowed with default settings. You can, however,configure your web site to get this done. This article is going to explain you that how one can do that.

Creating sub folders and classes

First of all, Create a new webSite in VS.NET 2005. Add App_Code folder to it. You can do so easily by right clicking on the web site in the Solution Explorer and choosing Add ASP.NET Folder” option (see below).

Once you add the App_Code folder add two class files – Class1.cs and Class2.vb. Note that one class file must be in C# where as the other must be in VB.NET. Add the following code in Class1.cs

public class Class1
{
    public static string HelloWorld()
    {
        return "Hello World From C# Method";
    }
}

Similarly, add the following code in Class2.vb.

Imports Microsoft.VisualBasic
Public Class Class2
    Public Shared Function HelloWorld() As String
        Return "Hello World From VB.NET Method"
   End Function
End Class

Both of these classes contain a method called HelloWorld() that simply return a string to the caller.
Now try compiling the web site. What happens? You will get an error as shown below:

Error 1 The files ‘/VBandCSharptogether/App_Code/Class2.vb’ and ‘/VBandCSharptogether/App_Code/Class1.cs’ use a
different language, which is not allowed since they need to be compiled together.

The error message tells us that we can not use different coding languages for the classes in App_Code folder. So does it mean that it's not possible. Well fortunately, there is a way to come over of this trap. First you need to put C# and VB.NET classes in separate sub-folders under App_Code. Secondly you need to add some markup in the web.config file to tell ASP.NET compiler about what you want to do.

<codeSubDirectories> Section

Create two folders under App_Code filder named CSCode and VBCode. Move Class1.cs inside CSCode folder and Class2.vb inside VBCode folder.

Add the following markup to it to web.config file:

<compilation debug="true">
<codeSubDirectories>
  <add directoryName="CSCode"/>
  <add directoryName="VBCode"/>
 </codeSubDirectories>
</compilation>

The section defines a set of sub-directories under the App_Code folder that are compiled at run time. The directoryName attribute points to the sub-folder of App_code. Each sub folder is compiled separately and hence each can have classes coded in different languages. We added our CSCode and VBCode folder in this section. This way the compiler will compile classes from CSCode and VBCode folders separately.

After configuring the web site try to compile it. This time it compiles successfully.

Enjoy….

SessionID changes with every request in the asp.net 2.0 application

noreply@blogger.com (Virendra) — Tue, 31 Mar 2009 08:12:00 +0000

For any web programmer, its obvious to think and believe that SessionId remains same through out the user session and it was right till asp.net1.1. But in asp.net2.0, this behavior has changed. In the asp.net application new sessionid is returned with the response to every request until session objects are not used.

According to MSDN the reason/solution is:
"When using cookie-based session state, ASP.NET does not allocate storage for session data until the Session object is used. As a result, a new session ID is generated for each page request until the session object is accessed. If your application requires a static session ID for the entire session, you can either implement the Session_Start method in the application's Global.asax file and store data in the Session object to fix the session ID, or you can use code in another part of your application to explicitly store data in the Session object."

Click here to view the article.

Enojy...

Exploring session in ASP.NET

noreply@blogger.com (Virendra) — Tue, 31 Mar 2009 08:09:00 +0000

This article describe about session in ASP.Net 2.0. It also explains about different types of session, their configuaration.

Enjoy.....

showModalDialog and postbacks in ASP.NET

noreply@blogger.com (Virendra) — Mon, 23 Mar 2009 08:53:00 +0000

I learned something new today that window.showModalDialog to open a modal window on the client from parent page using javascript, but whenever that page does a postback, it would open up a new window. A normal window.open works fine, this is the problem only with modal window.

Finally I found a solution which is very simple by just including the below tag in the section of the modal Window.

<base target="”_self”/">

And also we need to set the output cache property to “1″ otherwise next time when you try to open the modal window, it will take it from cache.

<%@ OutputCache Duration=”1″ VaryByParam=”none”%>

Enjoy..

Visual studio keyboard shortcuts

noreply@blogger.com (Virendra) — Fri, 06 Mar 2009 11:01:00 +0000

Download the cool PDF versions of all the keyboard shortcut available in Visual Studio 2005 and 2008.

For C#
For VB.NET

Make habit of using shortcut keys and save your time. :)

Enjoy...

ASP.NET Best Practices for High Performance Applications

noreply@blogger.com (Virendra) — Tue, 10 Feb 2009 06:43:00 +0000

Hi All,

I found some great articles on Best pracites and improving the performance of ASP.NET application. Check out these great articles.

Article 1

Article 2

Article 3

Enjoy....

SubmitDisabledControls - A New Property in ASP.NET 2.0

noreply@blogger.com (Virendra) — Mon, 09 Feb 2009 05:53:00 +0000

In one of my previous post, I blogged about ReadOnly and Enabled property of TextBox, One of the issues with disabled controls is that if controls are marked disabled on the client-side, the values are not posted back and therefore any changes are lost from the previous visit.

ASP.NET 2.0 add a new property “submitdisabledcontrols ” to HTMLForm Class, that when set to true will submit the disabled controls to the server also.

Enjoy…

ReadOnly and Enabled property of TextBox

noreply@blogger.com (Virendra) — Mon, 09 Feb 2009 05:50:00 +0000

One of thing about textbox that confuses me is the Enabled and ReadOnly Property. Both the property makes the text content non editable but there are couple of differences in the way they work. Here they are:-

Difference No. 1

When we use Enabled Property to false, Textbox’s text is grayed out and we cannot focus on the control and when we use ReadOnly property to true then you will see that the textbox’s content is not grayed out but the content is non editable.

Difference No. 2

When Enabled = “false” is used, control renders the HTML element as disabled=”disabled” and in case of ReadOnly=”true” then the HTML element is readonly=”readonly”.

I have read on some blogs that disabled controls values are not sent back to the server on postback but that’s not true. If you have disabled any control on client side then only its value will not be sent back to the server. Disabling on client side means either through JavaScript or by adding attributes to the control like

txt.Attributes.Add(”disabled”, “disabled”);

Enjoy…

Handle back button of the browser

noreply@blogger.com (Virendra) — Wed, 21 Jan 2009 09:44:00 +0000

The "Back" browser button cannot be actually disabled by a web application as the browser security will not allow this.
If we want user to stay on the same page, even if user presses back button, then we can use javascript to achieve this.

This method will always redirect to the user on the current page itself.

For example, user is on page 1 and user goes to Page 2. Now from page 2 if user press back button of the browser then user will be redirect to the page 2 itself.

window.history contains the collection of the page visited by the user for particular browser session. window.history.go(+1) and window.history.forward(); are same.

But if we want to display web page expired warning on the click of back button, then we must allow the browser to cache the page. This can be achieved by ASP.NET

/*To not to store the page in cache.*/

Response.ExpiresAbsolute = new DateTime(1900, 1, 1);

Response.Cache.SetCacheability(HttpCacheability.NoCache);

But one problem with this approach is that this will only work when there are some dynamic content in the page. i.e. change any combo or dropdown box value and then try to press back button.

If you can find out better solution then this please let me also know.

Enjoy...

Unable to evaluate expression because the code is optimized or a native frame is on top of the call stack

noreply@blogger.com (Virendra) — Sat, 03 Jan 2009 09:19:00 +0000

Few days ago, i come across with this strange error.

"Unable to evaluate expression because the code is optimized or a native frame is on top of the call stack."

When I debugged my code i found that this error message is coming due to following statment.

Response.Redirect(url);

I Used the following statement will fix the error.
Response.Redirect(url,false);

Response.Redirect internally calls to Response.End method due to this threadabort exception occurs. The Response.End method ends the page execution and shifts the execution to theApplication_EndRequest event in the application's event pipeline. The line of code that follows Response.End is not executed.

To work around this problem, use one of the following methods:

For Response.Redirect, use an overload, Response.Redirect(String url, bool endResponse) that passes false for the endResponse parameter to suppress the internal call to Response.End. For example:

Response.Redirect ("nextpage.aspx", false);

If you use this workaround, the code that follows Response.Redirect is executed.

For Server.Transfer, use the Server.Execute method instead.

Enjoy......

Count number of tables in a SQL Server database

noreply@blogger.com (Virendra) — Sat, 03 Jan 2009 09:16:00 +0000

A simple query to find out number of tables in database is

USE YOURDBNAME

SELECT COUNT(*) from information_schema.tables
WHERE table_type = 'base table'

Enjoy...

SET NOCOUNT (Transact-SQL)

noreply@blogger.com (Virendra) — Sat, 03 Jan 2009 09:12:00 +0000

Whenever we write any procedure and execute it a message appears in message window that shows no of rows affected with the statement written in the procedure and we become very happy to see that our procedure is working. But do you know that this message creates an extra overhead on the network? Yes it does.

By removing this extra overhead from the network, we can actually improve the performance of our database and our application.

How should we do it?
When you create any procedure then first line of your procedure should be

SET NOCOUNT ON;

This one line of code turns off the message that SQL server sends back to front end after every T-SQL statement is executed. This is applied for all SELECT, INSERT, UPDATE and DELETE statements. As when stored procedures are executed there is no need to pass this information back to front end.

When SET NOCOUNT is ON, the count is not returned. When SET NOCOUNT is OFF, the count is returned.If we still need to get the count of no of rows affected, we can still use @@ROWCOUNT option. Because The @@ROWCOUNT function is updated even when SET NOCOUNT is ON.

The setting specified by SET NOCOUNT is in effect at execute or run time and not at parse time.

Microsoft even realized the issue that this creates and has changed the stored procedure templates from SQL Server 2000 to SQL Server 2005.

Template used in SQL SERVER 2005

================================================
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- =============================================
-- Author:
-- Create date:
-- Description:
-- =============================================
CREATE PROCEDURE
-- Add the parameters for the stored procedure here
<@Param1, sysname, @p1> = ,
<@Param2, sysname, @p2> =
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;

-- Insert statements for procedure here
SELECT <@Param1, sysname, @p1>, <@Param2, sysname, @p2>
END
GO

================================================

Setting SET NOCOUNT to ON can provide a significant performance boost, because network traffic is greatly reduced.

Enjoy….

Weird thing with inner queries in SQL SERVER 2005

noreply@blogger.com (Virendra) — Sun, 30 Nov 2008 04:42:00 +0000

Few days ago, I found a very strange thing with SQL SERVER 2005 and I strongly feel that THIS IS A BUG in SQL SERVER which actually can create lots of data discrepancy.

To prove my point I have created a sample SQL Script. I want you to run the script in SQL SERVER.

Details of the Script

· Create new database.

CREATE DATABASE DB_TEST

· Use this Database.

USE DB_TEST

· Create a table named tblCategory

CREATE TABLE tblCategory
(
CategoryID INT PRIMARY KEY,
CategoryNAME VARCHAR(50)
)

· Create another table named tblProduct

CREATE TABLE tblProduct
(
ProductID INT PRIMARY KEY,
CategoryID INT FOREIGN KEY REFERENCES tblCategory(CategoryID),
ISCOMPLETED BIT
)

· Insert 5 rows in tblCategory

INSERT INTO tblCategory VALUES (1,'Category1')
INSERT INTO tblCategory VALUES (2,'Category2')
INSERT INTO tblCategory VALUES (3,'Category3')
INSERT INTO tblCategory VALUES (4,'Category4')
INSERT INTO tblCategory VALUES (5,'Category5')

· Insert 10 rows in tblProduct

INSERT INTO tblProduct VALUES (1,1,0)
INSERT INTO tblProduct VALUES (2,1,0)
INSERT INTO tblProduct VALUES (3,2,0)
INSERT INTO tblProduct VALUES (4,2,0)
INSERT INTO tblProduct VALUES (5,3,0)
INSERT INTO tblProduct VALUES (6,3,0)
INSERT INTO tblProduct VALUES (7,4,0)
INSERT INTO tblProduct VALUES (8,4,0)
INSERT INTO tblProduct VALUES (9,4,0)
INSERT INTO tblProduct VALUES (10,5,0)

· Select statement to confirm the data is inserted or not.

SELECT * FROM tblCategory
SELECT * FROM tblProduct

· Here is a select query which is not correct. The query tells select ProductID from tblCategory table where CategoryID = 1. But the problem here is tblCategory is not having a column named ProductID. So this query throws an error and that's a correct behaviour.

SELECT ProductID FROM tblCategory WHERE CategoryID = 1

· Here is the magic. I have used the above select query which is not correct as a inner query with a update statement. What to do you think? What will happen? Update query should throw an error. Logically it should.I was thinking the same But just execute this update query and you will be shocked.

UPDATE tblProduct SET IsCompleted = 1 WHERE ProductID IN (SELECT ProductID FROM tblCategory WHERE CategoryID = 1)

· Oops, 10 rows affected. Surpised. All the data in IsCompleted field is set to 1 but my inner query (SELECT ProductID FROM tblCategory WHERE CategoryID = 1) is wrong.

· This is just a sample query but When I executed such a similiar statement, 3364 rows in my table was updated.

SELECT * FROM tblCategory
SELECT * FROM tblProduct

I think this is a bug but actaully it's not. Please read comments for more information on this..

Java script function to get browser name..

noreply@blogger.com (Virendra) — Sun, 12 Oct 2008 05:55:00 +0000

We have this requirement in most of the application to know that which browser user is using to view the web site. We can use javascript to know browser name and this function works with all the broswers...

function GetBrowser()
{
           if (/Firefox[\/\s](\d+\.\d+)/.test(navigator.userAgent))
           {
                 var ffversion=new Number(RegExp.$1)
                 if (ffversion>=3)
                  alert("FF 3.x or above")
                 else if (ffversion>=2)
                  alert("FF 2.x")
                 else if (ffversion>=1)
                  alert("FF 1.x")
            }
            else if(/Chrome[\/\s](\d+\.\d+)/.test(navigator.userAgent))
            {
                 alert("Chrome.");
            }

   else if(/Opera[\/\s](\d+\.\d+)/.test(navigator.userAgent))
            {
                 alert("Opera");
            }
            else
            {
             alert(navigator.appName);
            }

            return false;
}

window.onload = GetBrowser;

Enjoy..............

ASP.Net Web Developement Solutions for C# and VB.Net

Get list of all currently running procedure in SQL Server

ASP.NET Coding Standards

Validate Blank Subject line for Outlook 2007

Access ViewState between Pages

Check/Uncheck All Checkboxes with JQuery

15 New Features of jQuery 1.4

Set Page Position after asyncPostback

Visual Studio List of Some ShortCut Keys

Introduction to Jquery

Introduction

History of JQuery

What can be done using JQuery

Demo

Referencehttp://jquery.com/

Conclusion

Difference between C# and VB.NET

AsyncFileUpload Control - New Control in Ajax Control ToolKit

AsyncFileUpload Control Features

Properties and Methods

Conclusion

Creating C# and VB.NET classes together using App_Code folder

SessionID changes with every request in the asp.net 2.0 application

Exploring session in ASP.NET

showModalDialog and postbacks in ASP.NET

Visual studio keyboard shortcuts

ASP.NET Best Practices for High Performance Applications

SubmitDisabledControls - A New Property in ASP.NET 2.0

ReadOnly and Enabled property of TextBox

Handle back button of the browser

Unable to evaluate expression because the code is optimized or a native frame is on top of the call stack

Count number of tables in a SQL Server database

SET NOCOUNT (Transact-SQL)

Weird thing with inner queries in SQL SERVER 2005

Java script function to get browser name..

Reference
http://jquery.com/