public void Add(string command, Action <RoutedEventArgs> action)
{
Bindings.Add(new CommandBinding(CommandExtension.CommandForString(command), (sender, e) => action(e)));
}
public void Add(string command, Action <RoutedEventArgs> action, Func <RoutedEventArgs, bool> func)
{
Bindings.Add(new CommandBinding(CommandExtension.CommandForString(command), (sender, e) => action(e), (sender, e) => e.CanExecute = func(e)));
}