Can't wrap my head around implementing KeyBindings

Question

Hi,

I want to handle hotkeys in my application. Writing a keybinding requires a command, which is fine, but it's not clear to me what is the minimum amount of work needed to implement that command. All the examples I seem to find are over-engineered, unclear or assume I'm using the MVVM pattern which I am not.

So what are the basics to getting a keybinding to work?

Thanks!

Answer 1

The easiest way to make a Keybinding I know of is doing something like this

in XAML

  <Window.CommandBindings>
    <CommandBinding Command="MyCommand" 
       CanExecute="MyCommandCanExecute"
       Executed="MyCommandExecuted" />
  </Window.CommandBindings>
  <Window.InputBindings>
    <KeyBinding Command="MyCommand" Key="M" Modifiers="Ctrl"/>
  </Window.InputBindings>

in code behind

private void MyCommandCanExecute(object sender, CanExecuteRoutedEventArgs e)
{
  e.CanExecute = true;
  e.Handled = true;
}

private void MyCommandExecuted(object sender, ExecutedRoutedEventArgs e)
{
  MessageBox.Show("Executed!");
  e.Handled = true;
}

It's pretty readable in my opinion, but if you have any questions leave a comment!

Answer 2

The minimum amount of work needed to implement a command is simply a class that implements ICommand. RoutedCommand is a simplistic implementation that provides the basic functionality.

Once you have that command set up, the KeyBinding is quite simple. You simply provide a Key, and optional Modifiers for that key. A number of common commands have been included in .NET. For example, you can bind the Copy command to Ctrl+C using this mark-up:

<Window.InputBindings>
 <KeyBinding Command="ApplicationCommands.Copy" Key="C" Modifiers="Ctrl"/>
</Window.InputBindings>

You can check out ApplicationCommands, ComponentCommands, and NavigationCommands for some other built-in commands.