Question

My MainWindow has some KeyBindings:

<Window.InputBindings>
   <KeyBinding Command="{Binding NewFileCommand}" Key="{Binding NewFileCommand.Key}" Modifiers="{Binding NewFileCommand.Modifiers}"  />
</Window.InputBindings>

They´re working, as long as i clicked somewhere into the content of my Window. But if I use Alt+Tab to switch between Applications (let´s say MS Word and my App) the Shortcuts won´t work anymore until I click again somewhere into the View. Same when selecting the Application-Window via Mouse on the Border.

How can I make them working?

Answer 1

In my repro, I used the RelayCommand from MVVM Light which worked fine. I’m guessing that you are using something else. Try adding this code in your window:

private void Window_Activated(object sender, EventArgs e)
{
    System.Windows.Input.CommandManager.InvalidateRequerySuggested();
}

That tells the command framework that something has changed and it should re-evaluate the CanExecute status of each command.