CommandEventArgs Class
Provides data for the Command event.
For a list of all members of this type, see CommandEventArgs Members.
System.Object
System.EventArgs
System.Web.UI.WebControls.CommandEventArgs
System.Web.UI.WebControls.DataGridCommandEventArgs
System.Web.UI.WebControls.DataListCommandEventArgs
System.Web.UI.WebControls.RepeaterCommandEventArgs
[Visual Basic] Public Class CommandEventArgs Inherits EventArgs [C#] public class CommandEventArgs : EventArgs [C++] public __gc class CommandEventArgs : public EventArgs [JScript] public class CommandEventArgs extends EventArgs
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Remarks
The Command event is raised when a Button or ImageButton control is clicked.
The CommandEventArgs object contains data about the Command event that can be accessed in the event handler. Using the properties available in the CommandEventArgs class, you can determine the name of the command to perform, such as Sort, in addition to an optional argument that supplements the command, such as Ascending.
For a list of initial property values for an instance of CommandEventArgs, see the CommandEventArgs constructor.
For more information about handling events, see Consuming Events.
Example
[Visual Basic, C#] The following example demonstrates how to access the properties in CommandEventArgs to determine the command to perform.
[Visual Basic] <%@ Page Language="VB" AutoEventWireup="True" %> <html> <head> <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 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"/> <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"/> <asp:Button id="Button4" Text="Unknown Command Name" CommandName="UnknownName" CommandArgument="UnknownArgument" OnCommand="CommandBtn_Click" runat="server"/> <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> [C#] <%@ Page Language="C#" AutoEventWireup="True" %> <html> <head> <script runat="server"> void CommandBtn_Click(Object sender, CommandEventArgs e) { switch(e.CommandName) { case "Sort": // Call the method to sort the list. Sort_List((String)e.CommandArgument); break; 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((String)e.CommandArgument == "") { // End the message. Message.Text += "."; } else { // Display an error message for the command argument. Message.Text += ", however the command argument is not recogized."; } break; default: // The command name is not recognized. Display an error message. Message.Text = "Command name not recogized."; break; } } void Sort_List(string commandArgument) { switch(commandArgument) { case "Ascending": // Insert code to sort the list in ascending order here. Message.Text = "You clicked the Sort Ascending button."; break; case "Descending": // Insert code to sort the list in descending order here. Message.Text = "You clicked the Sort Descending button."; break; default: // The command argument is not recognized. Display an error message. Message.Text = "Command argument not recogized."; break; } } </script> </head> <body> <form 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"/> <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"/> <asp:Button id="Button4" Text="Unknown Command Name" CommandName="UnknownName" CommandArgument="UnknownArgument" OnCommand="CommandBtn_Click" runat="server"/> <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> [Visual Basic] <%@ Page Language="VB" AutoEventWireup="True" %> <html> <head> <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 <b>Submit</b> 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 &= ", but 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 <b>Sort Ascending</b> button." Case "Descending" ' Insert code to sort the list in descending order here. Message.Text = "You clicked the <b>Sort Descending</b> button." Case Else ' The command argument is not recognized. Display an error message. Message.Text = "Command argument not recogized." End Select End Sub Sub Page_Load(sender As Object, e As EventArgs) ' Manually register the event-handling method for the Command ' event of the Button controls. AddHandler Button1.Command, AddressOf CommandBtn_Click AddHandler Button2.Command, AddressOf CommandBtn_Click AddHandler Button3.Command, AddressOf CommandBtn_Click AddHandler Button4.Command, AddressOf CommandBtn_Click AddHandler Button5.Command, AddressOf CommandBtn_Click End Sub </script> </head> <body> <form runat="server"> <h3>Button CommandName Example</h3> Click one of the command buttons. <br><br> <asp:Button id="Button1" Text="Sort Ascending" CommandName="Sort" CommandArgument="Ascending" runat="server"/> <asp:Button id="Button2" Text="Sort Descending" CommandName="Sort" CommandArgument="Descending" runat="server"/> <br><br> <asp:Button id="Button3" Text="Submit" CommandName="Submit" runat="server"/> <asp:Button id="Button4" Text="Unknown Command Name" CommandName="UnknownName" CommandArgument="UnknownArgument" runat="server"/> <asp:Button id="Button5" Text="Submit Unknown Command Argument" CommandName="Submit" CommandArgument="UnknownArgument" runat="server"/> <br><br> <asp:Label id="Message" runat="server"/> </form> </body> </html> [C#] <%@ Page Language="C#" AutoEventWireup="True" %> <html> <head> <script runat="server"> void CommandBtn_Click(Object sender, CommandEventArgs e) { switch(e.CommandName) { case "Sort": // Call the method to sort the list. Sort_List((String)e.CommandArgument); break; case "Submit": // Display a message for the Submit button being clicked. Message.Text = "You clicked the <b>Submit</b> button"; // Test whether the Command Argument is an empty string (""). if((String)e.CommandArgument == "") { // End the message. Message.Text += "."; } else { // Display an error message for the command argument. Message.Text += ", but the command argument is not recogized."; } break; default: // The command name is not recognized. Display an error message. Message.Text = "Command name not recogized."; break; } } void Sort_List(string commandArgument) { switch(commandArgument) { case "Ascending": // Insert code to sort the list in ascending order here. Message.Text = "You clicked the <b>Sort Ascending</b> button."; break; case "Descending": // Insert code to sort the list in descending order here. Message.Text = "You clicked the <b>Sort Descending</b> button."; break; default: // The command argument is not recognized. Display an error message. Message.Text = "Command argument not recogized."; break; } } void Page_Load(Object sender, EventArgs e) { // Manually register the event-handling method for the Command // event of the Button controls. Button1.Command += new CommandEventHandler(this.CommandBtn_Click); Button2.Command += new CommandEventHandler(this.CommandBtn_Click); Button3.Command += new CommandEventHandler(this.CommandBtn_Click); Button4.Command += new CommandEventHandler(this.CommandBtn_Click); Button5.Command += new CommandEventHandler(this.CommandBtn_Click); } </script> </head> <body> <form runat="server"> <h3>Button CommandName Example</h3> Click one of the command buttons. <br><br> <asp:Button id="Button1" Text="Sort Ascending" CommandName="Sort" CommandArgument="Ascending" runat="server"/> <asp:Button id="Button2" Text="Sort Descending" CommandName="Sort" CommandArgument="Descending" runat="server"/> <br><br> <asp:Button id="Button3" Text="Submit" CommandName="Submit" runat="server"/> <asp:Button id="Button4" Text="Unknown Command Name" CommandName="UnknownName" CommandArgument="UnknownArgument" runat="server"/> <asp:Button id="Button5" Text="Submit Unknown Command Argument" CommandName="Submit" CommandArgument="UnknownArgument" runat="server"/> <br><br> <asp:Label id="Message" runat="server"/> </form> </body> </html>
[C++, JScript] No example is available for C++ or JScript. To view a Visual Basic or C# example, click the Language Filter button
in the upper-left corner of the page.
Requirements
Namespace: System.Web.UI.WebControls
Platforms: Windows 2000, Windows XP Professional, Windows Server 2003 family
Assembly: System.Web (in System.Web.dll)
See Also
CommandEventArgs Members | System.Web.UI.WebControls Namespace | CommandEventHandler | Button.Command | ImageButton.Command