异步就是开启一个新的工作线程吗

  MessageBox.Show("当前线程唯一标示："+Thread.CurrentThread.ManagedThreadId.ToString());

            var request = HttpWebRequest.Create("http://www.baidu.com");

            request.BeginGetResponse((IAsyncResult ar) =>

            {

                MessageBox.Show("当前线程唯一标示：" + Thread.CurrentThread.ManagedThreadId.ToString());

                WebRequest req = ar.AsyncState as WebRequest;

                var response = request.EndGetResponse(ar);

                var stream = response.GetResponseStream(); 

                using (StreamReader reader = new StreamReader(stream))

                {

                    var content = reader.ReadLine(); 

                    //this.invoke是在拥有label1的窗口的线程上执行一个委托 否则在新线程里操作label1会跨线程 报错

                    this.Invoke(new MethodInvoker(() => {

                        label1.Text = content;

                    })); 

                }



            }, request);