多线程，异步委托，同步委托几种方式的区别

Code
        public delegate void DoThingsDelegate();
        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            //通过子线程调用方法  按钮事件可以执行
            Thread a = new Thread(new ThreadStart(DoSomeThing));
            a.IsBackground = true;
            a.Start();

            //虽然是异步委托  但是按钮根本就显示不出来
            DoThingsDelegate dothingsEvent = new DoThingsDelegate(DoSomeThing);
            IAsyncResult result = dothingsEvent.BeginInvoke(null, null);
            dothingsEvent.EndInvoke(result);

            //同步委托就更不行了
            dothingsEvent.Invoke();

            //真正的异步委托  异步调用方法，与多线程相似
            IAsyncResult result = dothingsEvent.BeginInvoke(new AsyncCallback(DoThingEnd), null);

        }
        public static void DoSomeThing()
        {
            Console.WriteLine("begin");
            Thread.Sleep(6000);
            Console.WriteLine("end");
        }
        public static void DoThingEnd(IAsyncResult result)
        {
            Console.WriteLine("end it");
        }
        private void button1_Click(object sender, RoutedEventArgs e)
        {
            MessageBox.Show("11111");
        }