Шаблон окна xaml

namespace Test_WindowTemplate.Commands
{
    public static class CommandsHelper
    {
        public static RelayCommand ApplicationShutdownCommand { get; } = new RelayCommand(Application.Current.Shutdown);
    }
 
    [MarkupExtensionReturnType(typeof(RelayCommand))]
    public class ApplicationShutdownCommandExtension : MarkupExtension
    {
        public override object ProvideValue(IServiceProvider serviceProvider)
        {
            return CommandsHelper.ApplicationShutdownCommand;
        }
    }
}

    public static class CommandsHelper
    {
        public static RelayCommand ApplicationShutdownCommand { get; } = new RelayCommand(Application.Current.Shutdown);
 
        public static ICommand GetCtrlQCommand(DependencyObject obj)
        {
            return (ICommand)obj.GetValue(CtrlQCommandProperty);
        }
 
        public static void SetCtrlQCommand(DependencyObject obj, ICommand value)
        {
            obj.SetValue(CtrlQCommandProperty, value);
        }
 
        // Using a DependencyProperty as the backing store for ApplicationShutdownInput.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty CtrlQCommandProperty =
            DependencyProperty.RegisterAttached(nameof(GetCtrlQCommand)[3..], typeof(ICommand), typeof(CommandsHelper), new PropertyMetadata(null, OnCtrlQCommandChanged));
 
        private static void OnCtrlQCommandChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            if(d is not UIElement elm)
            {
                throw new NotImplementedException("Реализовано только для UIElement.");
            }
            if(e.NewValue is ICommand command)
            {
                elm.InputBindings.Add(new KeyBinding(command, Key.Q, ModifierKeys.Control));
            }
        }
    }

    public partial class App : Application
    {
        protected override void OnStartup(StartupEventArgs e)
        {
            base.OnStartup(e);
 
            FrameworkElement.StyleProperty.OverrideMetadata(typeof(Window), new FrameworkPropertyMetadata
            {
                DefaultValue = Application.Current.FindResource(typeof(Window))
            });
        }
    }

internal class CommandsHelper
    {
        private static void ExceptionOnlyUIElement() => throw new NotImplementedException("Реализовано только для UIElement.");
 
        #region DragMoveWindowCommand
        public static RelayCommand DragMoveWindowCommand => new RelayCommand(DragMoveWindow);
 
        public static readonly DependencyProperty DragMoveWindowCommandProperty = DependencyProperty.RegisterAttached(
            nameof(DragMoveWindowCommand), typeof(ICommand), typeof(CommandsHelper), new PropertyMetadata(null, OnDragMoveWindowCommandChanged));
 
        public static ICommand GetDragMoveWindowCommand(DependencyObject obj) => (ICommand)obj.GetValue(DragMoveWindowCommandProperty);
 
        public static void SetDragMoveWindowCommand(DependencyObject obj, ICommand value) => obj.SetValue(DragMoveWindowCommandProperty, value);
 
        private static void OnDragMoveWindowCommandChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            if (!(d is UIElement))
            {
                ExceptionOnlyUIElement();
            }
 
            if (e.NewValue is ICommand command)
            {
                ((UIElement)d).InputBindings.Add(new MouseBinding(command, new MouseGesture(MouseAction.LeftClick)));
            }
        }
 
        private static void DragMoveWindow(object parameter) => (parameter as Window ?? App.FocusedWindow ?? App.ActiveWindow).DragMove();
        #endregion
}

    [MarkupExtensionReturnType(typeof(RelayCommand))]
    public class DragMoveWindowCommandExtension : MarkupExtension
    {
        public override object ProvideValue(IServiceProvider serviceProvider)
        {
            return CommandsHelper.DragMoveWindowCommand;
        }
    }