private void button1_Click(object sender, EventArgs e)
        {
            Thread thread = new Thread(new ThreadStart(ThreadTest));
            thread.Start();
        }

        private void ThreadTest()
        {
            UpdateTimeHandler ut = new UpdateTimeHandler(UpdateTime);
            this.Invoke(ut, DateTime.Now);
        }

        private void UpdateTime(DateTime dt)
        {
            this.label1.Text = dt.ToString();
        }

        private delegate void UpdateTimeHandler(DateTime dt);