multi key gesture in wpf - wpf

Question

I have a RoutedUICommand called Comment Selection. I need to add an input gesture for this command as it is in VIsual Studio, ie. (Ctrl+K, Ctrl+C).
How can I do this? Plz help me. (Keep VS functionality in mind).
Regards, Jawahar

Answer 1

This code is made for "Ctrl+W, Ctrl+E" and/or "Ctrl+W, E" combinations, however you can parametrize it for any key combinations:
XAML:
<MenuItem Header="Header" InputGestureText="Ctrl+W, E" Command="ShowCommand"/>
C#:
public static readonly RoutedUICommand ShowCommand = new RoutedUICommand(
"Show command text",
"Show command desc",
typeof(ThisWindow),
new InputGestureCollection(new[] { new ShowCommandGesture (Key.E) }));
public class ShowCommandGesture : InputGesture
{
private readonly Key _key;
private bool _gotFirstGesture;
private readonly InputGesture _ctrlWGesture = new KeyGesture(Key.W, ModifierKeys.Control);
public ShowCommandGesture(Key key)
{
_key = key;
}
public override bool Matches(object obj, InputEventArgs inputEventArgs)
{
KeyEventArgs keyArgs = inputEventArgs as KeyEventArgs;
if (keyArgs == null || keyArgs.IsRepeat)
return false;
if (_gotFirstGesture)
{
_gotFirstGesture = false;
if (keyArgs.Key == _key)
{
inputEventArgs.Handled = true;
}
return keyArgs.Key == _key;
}
else
{
_gotFirstGesture = _ctrlWGesture.Matches(null, inputEventArgs);
if (_gotFirstGesture)
{
inputEventArgs.Handled = true;
}
return false;
}
}
}

Answer 2

I've found this blog post which I think could be of help
http://kent-boogaart.com/blog/multikeygesture
Basically, WPF has no built in support for it, but subclassing InputGesture or KeyGesture seems like a possible way to achieve this without too much hassle.

Answer 3

Here's how I cobbled together something that actually works. I just wish I could credit the person or persons who paved the way to my Path of Enlightenment.
Let's say your application is called Heckler. Add a namespace tag for your application to the Window object:
<Window ...
xmlns:w="clr-namespace:Heckler"
...>
Now add a CommandBindings property tag and start your collection of CommandBinding objects. Here we add custom command Comment Selection:
<Window.CommandBindings>
<CommandBinding
Command="w:CustomCommands.CommentSelection"
CanExecute="CommentSelectionCanExecute"
Executed="CommentSelectionExecuted" />
</Window.CommandBindings>
Add a MenuItem to a main Menu's MenuItem:
<Menu
IsMainMenu="True">
<MenuItem
Header="_File">
<MenuItem
Command="w:CustomCommands.CommentSelection">
</MenuItem>
</MenuItem>
</Menu>
...
</Window>
In the Window code-behind, add your CustomCommands class and custom command:
public static class CustomCommands
{
// Ctrl+Shift+C to avoid collision with Ctrl+C.
public static readonly RoutedUICommand CommentSelection =
new RoutedUICommand("_Comment Selection",
"CommentSelection", typeof(MainWindow),
new InputGestureCollection()
{ new KeyGesture(Key.C, (ModifierKeys.Control | ModifierKeys.Shift)) });
}
Now wire up your event handlers:
private void CommentSelectionCanExecute(object sender, CanExecuteRoutedEventArgs e)
{
// Determines status of command.
e.CanExecute = true;
}
private void CommentSelectionExecuted(object sender, ExecutedRoutedEventArgs e)
{
// TO-DO: Insert magic here.
}
You should be good to go. I hope this helps and I didn't miss anything!

Answer 4

<KeyBinding Command="{Binding ExitCommand}"
Key="{Binding ExitCommand.GestureKey}"
Modifiers="{Binding ExitCommand.GestureModifier}"/>
get
{
if (exitCommand == null)
{
exitCommand = new DelegateCommand(Exit);
exitCommand.GestureKey = Key.X;
exitCommand.GestureModifier = ModifierKeys.Control;
exitCommand.MouseGesture = MouseAction.LeftDoubleClick;
}
return exitCommand;
}
}
private void Exit()
{
Application.Current.Shutdown();
}