c# 线程和Invoke互操作万用代码

            thAssist = new Thread(() =>
            {
                Invoke((ThreadStart)delegate()
                {
                    ctlProgressBar1.Visible = true;
                    ctlProgressBar1.Start();
                });

                try
                {
                    requestPage = WebRequest.Create(uri) as HttpWebRequest;
                    response = requestPage.GetResponse() as HttpWebResponse;
                }
                catch (WebException ex)
                {

                }
                finally
                {
                    StreamReader sr = new StreamReader(response.GetResponseStream(), Encoding.UTF8);
                    Invoke((ThreadStart)delegate()
                    {
                        textBox1.Text = sr.ReadToEnd();
                        //ctlProgressBar1.Stop();
                        //ctlProgressBar1.Visible = false;
                    });
                }
            });
            thAssist.Start();