CommandEventArgs..::.CommandArgument Property
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.NET Framework Class Library
CommandEventArgs..::.CommandArgument Property

Gets the argument for the command.

Namespace:  System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)
Syntax

'Usage

Dim instance As CommandEventArgs
Dim value As Object

value = instance.CommandArgument


'Declaration

Public ReadOnly Property CommandArgument As Object

Property Value

Type: System..::.Object
A System..::.Object that contains the argument for the command.
Remarks

The CommandArgument can contain any string set by the programmer. The CommandArgument property complements the CommandName property by allowing you to provide any additional information for the command. For example, you can set the CommandName property to Sort and set the CommandArgument property to Ascending to specify a command to sort in ascending order.

Examples

The following example demonstrates how to use the CommandArgument property to determine supplemental information for the command to perform.

<%@ Page Language="VB" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html  >
<head runat="server">
    <title>Button CommandName Example</title>
<script runat="server">

      Sub CommandBtn_Click(sender As Object, e As CommandEventArgs) 

         Select e.CommandName

            Case "Sort"

               ' Call the method to sort the list.
               Sort_List(CType(e.CommandArgument, String))

            Case "Submit"

               ' Display a message for the Submit button being clicked.
               Message.Text = "You clicked the Submit button"

               ' Test whether the command argument is an empty string ("").
               If CType(e.CommandArgument , String) = "" Then

                  ' End the message.
                  Message.Text &= "."

               Else

                  ' Display an error message for the command argument. 
                  Message.Text &= ", however the command argument is not recogized."

               End If                

            Case Else

               ' The command name is not recognized. Display an error message.
               Message.Text = "Command name not recogized."

         End Select

      End Sub

      Sub Sort_List(commandArgument As String)

         Select commandArgument

            Case "Ascending"

               ' Insert code to sort the list in ascending order here.
               Message.Text = "You clicked the Sort Ascending button."

            Case "Descending"

               ' Insert code to sort the list in descending order here.
               Message.Text = "You clicked the Sort Descending button."

            Case Else

               ' The command argument is not recognized. Display an error message.
               Message.Text = "Command argument not recogized."

         End Select

      End Sub

   </script>

</head>

<body>

   <form id="form1" runat="server">

      <h3>Button CommandName Example</h3>

      Click on one of the command buttons.

      <br /><br />

      <asp:Button id="Button1"
           Text="Sort Ascending"
           CommandName="Sort"
           CommandArgument="Ascending"
           OnCommand="CommandBtn_Click" 
           runat="server"/>

      &nbsp;

      <asp:Button id="Button2"
           Text="Sort Descending"
           CommandName="Sort"
           CommandArgument="Descending"
           OnCommand="CommandBtn_Click" 
           runat="server"/>

      <br /><br />

      <asp:Button id="Button3"
           Text="Submit"
           CommandName="Submit"
           OnCommand="CommandBtn_Click" 
           runat="server"/>

      &nbsp;

      <asp:Button id="Button4"
           Text="Unknown Command Name"
           CommandName="UnknownName"
           CommandArgument="UnknownArgument"
           OnCommand="CommandBtn_Click" 
           runat="server"/>

      &nbsp;

      <asp:Button id="Button5"
           Text="Submit Unknown Command Argument"
           CommandName="Submit"
           CommandArgument="UnknownArgument"
           OnCommand="CommandBtn_Click" 
           runat="server"/>

      <br /><br />

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

   </form>

</body>
</html>



Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Version Information

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0
See Also

Reference

Other Resources

Community Content

Why is CommandArgument a System.Object?
Added by:Yop83
Why is the CommandArgument property a System.Object and not a string, seeing as in most cases you input the CommandArgument in a string property of a UI control?

For instance, the CommandArgument property of the LinkButton is a string.

I'm curious to see what the reason behind this design is...

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