WPF 附加属性的用法 (一)

 

public class MDCTest
    {
        public static DependencyProperty MouseDoubleClickCommandProperty = DependencyProperty.RegisterAttached(
            "MouseDoubleClick",
            typeof(ICommand),
            typeof(MDCTest),
            new FrameworkPropertyMetadata(null, new PropertyChangedCallback(MouseDoubleClickChanged))
            );
        public static void SetMouseDoubleClick(DependencyObject target, ICommand value)
        {
            target.SetValue(MDCTest.MouseDoubleClickCommandProperty, value);
        }
        public static ICommand GetMouseDoubleClick(DependencyObject target)
        {
            return (ICommand)target.GetValue(MDCTest.MouseDoubleClickCommandProperty);
        }
        private static void MouseDoubleClickChanged(DependencyObject target, DependencyPropertyChangedEventArgs e)
        {
            Control control = target as Control;
            if (control != null)
            {
                if (e.NewValue != null && e.OldValue == null)
                {
                    control.MouseDoubleClick += new MouseButtonEventHandler(control_MouseDoubleClick);
                }
                else if (e.NewValue == null && e.OldValue != null)
                {
                    control.MouseDoubleClick -= new MouseButtonEventHandler(control_MouseDoubleClick);
                }
            }
        }
        public static void control_MouseDoubleClick(object sender, MouseButtonEventArgs e)
        {
            Control control = sender as Control;
            ICommand command = (ICommand)control.GetValue(MDCTest.MouseDoubleClickCommandProperty);
            command.Execute(control);
        }
    }

public class RelayCommand : ICommand
    {
        private Action