class MyButton : Button
    {
        public Type UserWindowType { get; set; }
        protected override void OnClick()
        {
            base.OnClick();
            Window win = Activator.CreateInstance(this.UserWindowType) as Window;
            if (win != null)
            {
                win.ShowDialog();
            }
        }

这段话是什么意思啊，哪位高人仔细讲讲啊！！！！！！！！！！