How can I assign the 'Close on Escape-key pres

问题:

Is there any straightforward way of telling the whole WPF application to react to Escape key presses by attempting to close the currently focused widow? It is not a great bother to manually setup the command- and input bindings but I wonder if repeating this XAML in all windows is the most elegant approach?

<Window.CommandBindings>
        <CommandBinding Command="Close" Executed="CommandBinding_Executed" />
</Window.CommandBindings>
<Window.InputBindings>
        <KeyBinding Key="Escape" Command="Close" />
</Window.InputBindings>

Any constructive suggestions welcome!

回答1:

All I can suggest to improve on that is to remove the need for an event handler by binding to a static command instance.

Note: this will only work in .NET 4 onwards as it requires the ability to bind to the KeyBinding properties.

First, create a command that takes a Window as a parameter and calls Close within the Execute method:

public class CloseThisWindowCommand : ICommand
{
    #region ICommand Members

    public bool CanExecute(object parameter)
    {
        //we can only close Windows
        return (parameter is Window);
    }

    public event EventHandler CanExecuteChanged;

    public void Execute(object parameter)
    {
        if (this.CanExecute(parameter))
        {
            ((Window)parameter).Close();
        }
    }

    #endregion

    private CloseThisWindowCommand()
    {

    }

    public static readonly ICommand Instance = new CloseThisWindowCommand();
}

Then you can bind your KeyBinding to the static Instance property:

<Window.InputBindings>
    <KeyBinding Key="Escape" Command="{x:Static local:CloseThisWindowCommand.Instance}" CommandParameter="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=Window}}" />
</Window.InputBindings>

I don't know that this is necessarily better than your approach, but it does mean marginally less boilerplate at the top of every Window and that you don't need to include an event handler in each

回答2:

Or you could just add a button with Cancel as text and set IsCancel = True. Then Escape will work as default command to close.

回答3:

create RoutedUICommand like below

 private static RoutedUICommand EscUICommand = new RoutedUICommand("EscBtnCommand"
       , "EscBtnCommand"
       , typeof(WindowName)
       , new InputGestureCollection(new InputGesture[] 
           { new KeyGesture(Key.Escape, ModifierKeys.None, "Close") }));

and add it command binding in constructor

CommandBindings.Add(new CommandBinding(EscUICommand, (sender, e) => { this.Hide(); }));

回答4:

On Windows shown with ShowDialog() you can use:

<!-- Button to close on Esc -->
<Button IsCancel="True" Width="0" Height="0"/>

回答5:

Another possible way is to use attached properties

Bellow is a gist code:

<script src="https://gist.github.com/meziantou/1e98d7d7aa6aa859d916.js"></script>

回答6:

You can also use PreviewKeyDown Event

PreviewKeyDown="UserControl_PreviewKeyDown"

Code behind call you close command

private void UserControl_PreviewKeyDown(object sender, System.Windows.Input.KeyEventArgs e)
        {
            if (e.Key == Key.Escape)
            {
                _vm.OnCloseCommand(sender);
            }
        }

回答7:

None of above worked for me, except Kai's. I modified his answer: I added 'btn_close.IsCancel = true;' to constructor. SettingsWindow is my second window, and main window is (default) MainWindow.

  public partial class SettingsWindow : Window {
    public SettingsWindow() {
      InitializeComponent();
      btn_close.IsCancel = true;
    }
    private void btn_close_Click(object sender, RoutedEventArgs e) {
      this.Close();
    }
  }

Hope it helps,

Simon S love nia