CommandEventArgs.CommandArgument 属性

CommandEventArgs.CommandArgument 属性

获取命令的参数。

[Visual Basic]

Public ReadOnly Property CommandArgument As Object

[C#]

public object CommandArgument {get;}

[C++]

public: __property Object* get_CommandArgument();

[JScript]

public function get CommandArgument() : Object;

属性值

包含该命令参数的 System.Object

备注

CommandArgument 可以包含由程序员设置的任何字符串。CommandArgument 属性通过允许您为该命令提供任何附加信息,对 CommandName 属性加以补充。例如,您可以将 CommandName 属性设置为 Sort,将 CommandArgument 属性设置为 Ascending,从而指定一个以升序进行排序的命令。

示例

[Visual Basic, C#] 下面的示例展示如何使用 CommandArgument 属性来确定要执行的命令的补充信息。

[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"/>

&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>

[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"/>

&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>

[C++, JScript] 没有可用于 C++ 或 JScript 的示例。若要查看 Visual Basic 或 C# 示例,请单击页左上角的“语言筛选器”按钮 。

要求

平台: Windows 2000, Windows XP Professional, Windows Server 2003 系列

请参见

CommandEventArgs 类 | CommandEventArgs 成员 | System.Web.UI.WebControls 命名空间 | Button.CommandArgument | CommandArgument | CommandEventArgs 成员(Visual J# 语法) | C++ 托管扩展

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