tags

InputBinding

[VS2010] Binding support in InputBindings

THE feature that was missing from WPF ! Visual Studio 2010 beta 2 has been released last week, and it brings to WPF a long awaited feature : support for bindings in InputBindings. As a reminder, the issue in previous releases was that the Command property of the InputBinding class wasn't a DependencyProperty, so it wasn't possible to bind it. Furthermore, InputBindings didn't inherit the parent DataContext, which made it difficult to provide alternative implementations… Until now, in order to bind the Command of a KeyBinding or MouseBinding to a property of the DataContext, we had to resort to clumsy workarounds… I had eventually came up with an acceptable solution, described in this post, but I wasn't really satisfied with it (it used reflection on private members, and had annoying limitations).

[WPF] Using InputBindings with the MVVM pattern

If you develop WPF applications according to the Model-View-ViewModel pattern, you may have faced this issue : in XAML, how to bind a key or mouse gesture to a ViewModel command ? The obvious and intuitive approach would be this one : <UserControl.InputBindings> <KeyBinding Modifiers="Control" Key="E" Command="{Binding EditCommand}"/> </UserControl.InputBindings> Unfortunately, this code doesn't work, for two reasons : The Command property is not a dependency property, so you cannot assign it through binding InputBindings are not part of the logical or visual tree of the control, so they don't inherit the DataContext A solution would be to create the InputBindings in the code-behind, but in the MVVM pattern we usually prefer to avoid this… I spent a long time looking for alternative solutions to do this in XAML, but most of them are quite complex and unintuitive.