Button.Command (Evento)
Se produce cuando se hace clic en el control Button.
Espacio de nombres: System.Web.UI.WebControls
Ensamblado: System.Web (en system.web.dll)
Ensamblado: System.Web (en system.web.dll)
Se provoca el evento Command cuando se hace clic en el control Button. Este evento suele utilizarse cuando hay un nombre de comando, como Sort, asociado al control Button. Esto permite crear varios controles Button en una página Web y determinar mediante programación en qué control Button se hace clic.
 Nota: |
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| Se provoca el evento Command mediante la jerarquía de controles con el formato de BubbleEvent. |
Para obtener más información sobre el control de eventos, vea Utilizar eventos.
En el ejemplo de código se muestra cómo especificar y crear codificar el controlador del evento Command para ordenar una lista cuando se haga clic en el control Button. En este ejemplo se especifica el controlador de eventos de forma declarativa mediante la propiedad OnClick del control Button.
<%@ 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 runat="server"> <title>Button CommandName Example</title> <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 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"/> <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>
En el siguiente ejemplo de código se muestra cómo especificar el controlador de eventos y agregarlo mediante programación al evento en el método Page_Load.
<%@ 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 runat="server"> <title>Button CommandName Example</title> <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 id="form1" 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>
Windows 98, Windows 2000 Service Pack 4, Windows CE, Windows Millennium, Windows Mobile para Pocket PC, Windows Mobile para Smartphone, Windows Server 2003, Windows XP Media Center, Windows XP Professional x64, Windows XP SP2, Windows XP Starter
Microsoft .NET Framework 3.0 es compatible con Windows Vista, Microsoft Windows XP SP2 y Windows Server 2003 SP1.