CanExecuteRoutedEventArgs.CanExecute 屬性

public:
 property bool CanExecute { bool get(); void set(bool value); };

public bool CanExecute { get; set; }

member this.CanExecute : bool with get, set

Public Property CanExecute As Boolean

屬性值

true若事件能在指令目標上執行;否則，。 false 預設值為 false。

範例

以下範例會產生 CanExecuteRoutedEventHandler 一個，只有當指令目標是控制點時才會回傳真。 首先， Source 事件資料會被鑄造為 Control。 若為 Control， CanExecute 則設為 true;否則，為 false。

// CanExecuteRoutedEventHandler that only returns true if
// the source is a control.
private void CanExecuteCustomCommand(object sender, 
    CanExecuteRoutedEventArgs e)
{
    Control target = e.Source as Control;
    
    if(target != null)
    {
        e.CanExecute = true;
    }
    else
    {
        e.CanExecute = false;
    }
}

' CanExecuteRoutedEventHandler that only returns true if
' the source is a control.
Private Sub CanExecuteCustomCommand(ByVal sender As Object, ByVal e As CanExecuteRoutedEventArgs)
    Dim target As Control = TryCast(e.Source, Control)

    If target IsNot Nothing Then
        e.CanExecute = True
    Else
        e.CanExecute = False
    End If
End Sub

備註

許多指令來源，如 MenuItem 和 Button，當 CanExecute 是 false 時會被停用，當 CanExecute 是 true時會被啟用 。

另請參閱

• CanExecuteRoutedEventHandler
• CommandBinding
• CommandManager