private void button1_Click(object sender, EventArgs e)

        {

            Action<string> action = new Action<string>((s) => {

                System.Threading.Thread.Sleep();

                MessageBox.Show("sleep 5000 ms" + " IsThreadPoolThread:" + System.Threading.Thread.CurrentThread.IsThreadPoolThread + " ID:" + System.Threading.Thread.CurrentThread.ManagedThreadId);

            });

            //委托的同步异步调用

            //BeginInvoke 使用线程池执行委托

           // IAsyncResult result = action.BeginInvoke(null, new AsyncCallback((s) => { MessageBox.Show("执行完毕!" + s.AsyncState + " IsThreadPoolThread:" + System.Threading.Thread.CurrentThread.IsThreadPoolThread); }), "执行完成，回调传入参数!");

           ////result.AsyncWaitHandle.WaitOne();

           // action.EndInvoke(result);

           // result.AsyncWaitHandle.Close();

            ////Invoke 同步调用 ， 默认使用当前线程

            action.Invoke("传入参数!");

            System.Threading.Thread.Sleep();

            MessageBox.Show("sleep 1000 ms  ID:" + System.Threading.Thread.CurrentThread.ManagedThreadId);

            //UI 控件 Invoke 特点

            //this.InvokeRequired  判断当前线程是否是UI线程

            //this.Invoke(...)  同步在UI线程调用指定方法

            //this.BeginInvoke(...)  异步在UI 线程调用指定方法

     }