ImageButton.Command Event (System.Web.UI.WebControls)

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.NET Framework Class Library

ImageButton.Command Event

Occurs when the ImageButton is clicked.

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

Syntax

Visual Basic

Public Event Command As CommandEventHandler

public event CommandEventHandler Command

Visual C++

public:
virtual  event CommandEventHandler^ Command {
	void add (CommandEventHandler^ value);
	void remove (CommandEventHandler^ value);
}

abstract Command : IEvent<CommandEventHandler,
    CommandEventArgs>
override Command : IEvent<CommandEventHandler,
    CommandEventArgs>

ASP.NET

<asp:ImageButton OnCommand="CommandEventHandler" />

Implements

IButtonControl.Command

Remarks

The Command event is raised when an ImageButton control is clicked.

Note
The Command event is raised through the control hierarchy in the form of the BubbleEvent.

Note
This event causes the page to post back to the server.

For more information about handling events, see How to: Consume Events in a Web Forms Application.

Examples

The following example demonstrates how to specify and code a handler for the Command event to determine which ImageButton control is clicked.

Note
The following code sample uses the single-file code model and may not work correctly if copied directly into a code-behind file. This code sample must be copied into an empty text file that has an .aspx extension. For more information on the Web Forms code model, see ASP.NET Web Page Code Model.

Visual Basic


<%@ 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 xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>ImageButton CommandName Sample</title>
<script language="VB" runat="server">

      Sub ImageButton_Command(sender As Object, e As CommandEventArgs) 
         If (e.CommandName = "Sort") And (e.CommandArgument = "Ascending") Then
            Label1.Text = "You clicked the Sort Ascending Button"
         Else
            Label1.Text = "You clicked the Sort Descending Button"
         End If
      End Sub

   </script>

</head>

<body>

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

      <h3>ImageButton CommandName Sample</h3>

      Click an image.<br /><br />

      <asp:ImageButton id="imagebutton1" runat="server"
           AlternateText="Sort Ascending"
           ImageUrl="images/pict.jpg"
           OnCommand="ImageButton_Command"
           CommandName="Sort"
           CommandArgument="Ascending"/>

      <asp:ImageButton id="imagebutton2" runat="server"
           AlternateText="Sort Descending"
           ImageUrl="images/pict2.jpg"
           OnCommand="ImageButton_Command"
           CommandName="Sort"
           CommandArgument="Descending"/>

      <br /><br />

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

   </form>

</body>
</html>


<%@ Page Language="C#" AutoEventWireup="True" %>
<!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>
    <title>ImageButton CommandName Sample</title>
<script language="C#" runat="server">

      void ImageButton_Command(object sender, CommandEventArgs e) 
      {
         if (e.CommandName == "Sort" && e.CommandArgument == "Ascending")
            Label1.Text = "You clicked the Sort Ascending Button";
         else
            Label1.Text = "You clicked the Sort Descending Button";
      }

   </script>

</head>

<body>

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

      <h3>ImageButton CommandName Sample</h3>

      Click an image.<br /><br />

      <asp:ImageButton id="imagebutton1" runat="server"
           AlternateText="Sort Ascending"
           ImageUrl="images/pict.jpg"
           OnCommand="ImageButton_Command"
           CommandName="Sort"
           CommandArgument="Ascending"/>

      <asp:ImageButton id="imagebutton2" runat="server"
           AlternateText="Sort Descending"
           ImageUrl="image/pict2.jpg"
           OnCommand="ImageButton_Command"
           CommandName="Sort"
           CommandArgument="Descending"/>

      <br /><br />

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

   </form>

</body>
</html>

Version Information

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Reference

ImageButton Class

System.Web.UI.WebControls Namespace

OnCommand

CommandEventHandler

Other Resources

Button Web Server Controls Content Map

How to: Consume Events in a Web Forms Application