Question

I wish to receive commands in my ViewModel (i.e. no code in view at all). I have setup KeyBindings in the view but I’m unsure how to construct the command on the view model, how do I do this? I have tried the code below but it is never called.

I receive this error in the output window

BindingExpression path error: ‘ShowHelp’ property not found on
‘object’ ”String’ (HashCode=-1833871577)’.
BindingExpression:Path=ShowHelp; DataItem=’String’
(HashCode=-1833871577); target element is ‘KeyBinding’
(HashCode=60325168); target property is ‘Command’ (type ‘ICommand’)

viewModel is defined like so: (note this works for all other binding in the window)

<app:ViewModel x:Key="viewModel"></app:ViewModel>

XAML:

<Window.InputBindings>
    <KeyBinding Command="{Binding ShowHelp, Source=viewModel}" Gesture="ALT+H" />
</Window.InputBindings>

ViewModel Code

This is where I have started with the ViewModel code to execute the command, if this is wrong please advise 🙂

public class ShowHelpCommand : ICommand
{
    public bool CanExecute(object parameter)
    {
        return true;
    }

    public event EventHandler CanExecuteChanged;

    public void Execute(object parameter)
    {
        Console.WriteLine("SHOW HELP");
    }
}
public ICommand ShowHelp { get;  set; }
ShowHelp = new ShowHelpCommand();

Answer 1

Isn’t it a missing StaticResource?

<KeyBinding Command="{Binding ShowHelp, Source={StaticResource viewModel}}" Gesture="ALT+H" />