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Button.CommandArgument Vlastnost

Definice

Získá nebo nastaví volitelný parametr předaný do Command události spolu s přidruženým CommandName.

public:
 property System::String ^ CommandArgument { System::String ^ get(); void set(System::String ^ value); };
[System.ComponentModel.Bindable(true)]
public string CommandArgument { get; set; }
[System.ComponentModel.Bindable(true)]
[System.Web.UI.Themeable(false)]
public string CommandArgument { get; set; }
[<System.ComponentModel.Bindable(true)>]
member this.CommandArgument : string with get, set
[<System.ComponentModel.Bindable(true)>]
[<System.Web.UI.Themeable(false)>]
member this.CommandArgument : string with get, set
Public Property CommandArgument As String

Hodnota vlastnosti

Volitelný parametr předaný události Command spolu s přidruženým CommandNameparametrem . Výchozí hodnota je Empty.

Implementuje

Atributy

Příklady

Následující příklad kódu ukazuje, jak použít CommandArgument vlastnost k vytvoření Button ovládacího prvku, který seřadí seznam ve vzestupném pořadí.

<%@ 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>
<%@ 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 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"/>

       

      <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>

Poznámky

CommandArgument Pomocí vlastnosti určete parametr, který tuto vlastnost doplňujeCommandName.

Poznámka

I když můžete nastavit CommandArgument vlastnost samostatně, obvykle se používá pouze v případě, že je vlastnost také nastavena CommandName .

Vlastnost CommandArgument doplňuje CommandName vlastnost tím, že umožňuje zadat další informace o příkazu, který se má provést. Pokud například nastavíte CommandName vlastnost na Sort a CommandArgument vlastnost na Ascending, zadáte příkaz pro řazení ve vzestupném pořadí.

Tuto vlastnost nelze nastavit pomocí motivů nebo šablon stylů. Další informace najdete v tématu ThemeableAttribute a ASP.NET motivy a vzhledy.

Platí pro

Viz také