Extend DependsOnAttribute for commands

When using an RelayCommand (e.g. from MvvmLight), where the CanExecute depends on the value of a property, the DependsOnAttribute could be extended, so each time the property changes, the RaiseCanExecuteChanged() method of the command is invoked.

[tom-englert]

Raising a property change event on the command property itself should have the same effect as triggering the CommandManager.InvalidateRequerySuggested() , so that should work already:

public class SurveyViewModel
{
    public bool IsSubmitEnabled { get; set; }

    [DependsOn(nameof(IsSubmitEnabled))]
    public RelayCommand SubmitCommand => new RelayCommand(OnSubmit, CanSubmit);

    public bool CanSubmit()
    {
        return IsSubmitEnabled;
    }
    public void OnSubmit(){
        ...
    }        
}

[zihotki]

@tom-englert Good point, somehow I didn’t think about it. Tested and verified that it indeed works like a charm.