//主线程

 public delegate void UpdateMessage(string mes);

 public void UpdatePortMessage(string mes)

        {

            this.txtMessage.AppendText(string.Format("Connected {0}. succeed", mes) + "\r\n");

            this.txtClientIP.Text = mes;

        }

// 线程1

  UpdateMessage upPort = new UpdateMessage(UpdatePortMessage);

                        this.BeginInvoke(upPort, point);