public abstract class CustomUICommandBase: ICommand, INotifyPropertyChanged
    {
        #region Private members
        private string _text;
        private string _inputGestureText;
        private ImageSource _icon;
        private KeyGesture _gesture;
        private readonly Func<object, bool> _condition;
        private readonly Action<object> _action;
        #endregion

        #region Properties
        public Type OwnerType { get; private set; }
        public KeyGesture Gesture
        {
            get { return _gesture; }
            set
            {
                if (Equals(value, _gesture)) return;
                _gesture = value;

                InputGestureText = GetGuestureTextFrom(_gesture);
                OnPropertyChanged();
            }
        }
        public string InputGestureText
        {
            get { return _inputGestureText; }
            private set
            {
                if (value == _inputGestureText) return;
                _inputGestureText = value;
                OnPropertyChanged();
            }
        }
        public string Text
        {
            get { return _text; }
            set
            {
                if (value == _text) return;
                _text = value;
                OnPropertyChanged();
            }
        }
        public ImageSource Icon
        {
            get { return _icon; }
            set
            {
                if (Equals(value, _icon)) return;
                _icon = value;
                OnPropertyChanged();
            }
        } 
        #endregion

        #region ICommand
        public bool CanExecute(object parameter)
        {
            return (null == _condition) || _condition(parameter);
        }
        public void Execute(object parameter)
        {
            _action(parameter);
        }
        public event EventHandler CanExecuteChanged
        {
            add { CommandManager.RequerySuggested += value; }
            remove { CommandManager.RequerySuggested -= value; }
        }
        #endregion

        #region INotifyPropertyChanged
        public event PropertyChangedEventHandler PropertyChanged;

        [NotifyPropertyChangedInvocator]
        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
        } 
        #endregion

        #region .ctor
        protected CustomUICommandBase(Action<object> action, Func<object, bool> condition = null, Type type = null)
        {
            _action = action;
            _condition = condition;
            OwnerType = type;
        } 
        #endregion

        public static string GetGuestureTextFrom(KeyGesture gesture)
        {
            if (default(KeyGesture) == gesture)
                return String.Empty;

            string defaultModifier = default(ModifierKeys).ToString();

            string key = gesture.Key.ToString();
            string modifierAlt = (ModifierKeys.Alt & gesture.Modifiers).ToString();
            string modifierControl = (ModifierKeys.Control & gesture.Modifiers).ToString();
            string modifierShift = (ModifierKeys.Shift & gesture.Modifiers).ToString();
            string modifierWindows = (ModifierKeys.Windows & gesture.Modifiers).ToString();

            return string.Format(
                "{0}{1}{2}{3}{4}",
                0 == String.CompareOrdinal(modifierControl, defaultModifier) ? String.Empty : "Ctrl+",
                0 == String.CompareOrdinal(modifierAlt, defaultModifier) ? String.Empty : "Alt+",
                0 == String.CompareOrdinal(modifierShift, defaultModifier) ? String.Empty : "Shift+",
                0 == String.CompareOrdinal(modifierWindows, defaultModifier) ? String.Empty : "Win+",
                key);
        }
    }

    public class ExitUICommand : CustomUICommandBase
    {
        private static readonly Action<object> _action = o =>
            {
                if (MessageBoxResult.Yes == MessageBox.Show("Вы уверены, что хотите завершить приложение?", "Подтверждение выхода", MessageBoxButton.YesNo, MessageBoxImage.Question))
                    Application.Current.Shutdown();
            };

        public ExitUICommand(Action<object> action, Func<object, bool> condition = null, Type type = null) 
            : base(action, condition, type) { }

        public ExitUICommand(Func<object, bool> condition = null, Type type = null)
            : base(_action, condition, type) { }
    }

    public class RoutedCommands
    {
        public static ICommand QuitCommand = new ExitUICommand() {Gesture = new KeyGesture(Key.Q, ModifierKeys.Control), Text = "Quit", Icon = new BitmapImage(new Uri("/Market;component/Images/delete.png", UriKind.Relative))};
    }

<Window
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
        xmlns:uiCommands="clr-namespace:Market.UICommands"
        x:Class="Market.MainWindow"
        Title="MainWindow" Height="466" Width="974" Loaded="Window_Loaded">

    <Window.InputBindings>
        <KeyBinding Key="Q" Modifiers="Control" Command="{x:Static uiCommands:RoutedCommands.QuitCommand}"></KeyBinding>
    </Window.InputBindings>
    
    <DockPanel LastChildFill="True">
        <Menu x:Name="MainMenu" DockPanel.Dock="Top">
            <MenuItem Header="_Файл">
                <Separator/>
                <MenuItem 
                    InputGestureText="{Binding Command.InputGestureText, RelativeSource={RelativeSource Self}}" 
                    Header="{Binding Command.Text, RelativeSource={RelativeSource Self}}" 
                    Command="{x:Static uiCommands:RoutedCommands.QuitCommand}"/>
            </MenuItem>
        </Menu>

        <DockPanel DockPanel.Dock="Top">
            <ToolBar DockPanel.Dock="Left">
                <Button Command="{x:Static uiCommands:RoutedCommands.QuitCommand}">
                    <Image Source="{Binding Command.Icon, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Button}}}" Width="16" Height="16"/>
                </Button>
            </ToolBar>
        </DockPanel>

        <TabControl DockPanel.Dock="Bottom">
            <TabItem Header="TabItem">
                <Grid Background="#FFE5E5E5">
                    <Button Command="{x:Static uiCommands:RoutedCommands.QuitCommand}">
                        <TextBlock Text="{Binding Command.Text, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Button}}}"></TextBlock>
                    </Button>
                </Grid>
            </TabItem>
            <TabItem Header="TabItem">
                <Grid Background="#FFE5E5E5"/>
            </TabItem>
        </TabControl>
    </DockPanel>
</Window>