CommandBinding.CanExecute Event
Definition
Occurs when the command associated with this CommandBinding initiates a check to determine whether the command can be executed on the command target.
public:
event System::Windows::Input::CanExecuteRoutedEventHandler ^ CanExecute;
public event System.Windows.Input.CanExecuteRoutedEventHandler CanExecute;
member this.CanExecute : System.Windows.Input.CanExecuteRoutedEventHandler
Public Custom Event CanExecute As CanExecuteRoutedEventHandler
Public Event CanExecute As CanExecuteRoutedEventHandler
Event Type
Examples
The following example creates a CommandBinding that maps an ExecutedRoutedEventHandler and a CanExecuteRoutedEventArgs handler to the Open command.
<Window.CommandBindings>
<CommandBinding Command="ApplicationCommands.Open"
Executed="OpenCmdExecuted"
CanExecute="OpenCmdCanExecute"/>
</Window.CommandBindings>
// Creating CommandBinding and attaching an Executed and CanExecute handler
CommandBinding OpenCmdBinding = new CommandBinding(
ApplicationCommands.Open,
OpenCmdExecuted,
OpenCmdCanExecute);
this.CommandBindings.Add(OpenCmdBinding);
' Creating CommandBinding and attaching an Executed and CanExecute handler
Dim OpenCmdBinding As New CommandBinding(ApplicationCommands.Open, AddressOf OpenCmdExecuted, AddressOf OpenCmdCanExecute)
Me.CommandBindings.Add(OpenCmdBinding)
The following shows the CanExecuteRoutedEventHandler which sets CanExecute to true
.
void OpenCmdCanExecute(object sender, CanExecuteRoutedEventArgs e)
{
e.CanExecute = true;
}
Private Sub OpenCmdCanExecute(ByVal sender As Object, ByVal e As CanExecuteRoutedEventArgs)
e.CanExecute = True
End Sub
Remarks
When the CanExecute method on a RoutedCommand is called, the PreviewCanExecute event is raised on the command target. If the event is not handled, the CanExecute event is raised. If the command target has a CommandBinding for the command, the CanExecute handler for that CommandBinding is called. If the command target does not have a CommandBinding for the command, the CanExecute event bubbles up the element tree searching for an element that has a CommandBinding associated with the command.
Routed Event Information
Identifier field | CanExecuteEvent |
Routing strategy | Bubbling |
Delegate | CanExecuteRoutedEventHandler |
- The corresponding tunneling event is PreviewCanExecute.