private void button1_Click(object sender, EventArgs e)
        {
            Thread th = new Thread(new ThreadStart(Test));
            th.Start();
         }
       
        public void Test()
        {
            for (int i = 0; i <= 20; i++)
            {
                for (int j = 0; j < 100; j++)
                {
                    ViewLable(i.ToString()+"-"+j.ToString());
                }
            }
        }
        public delegate void ViewLableDelegate(string str);//定义一个委托
        public void ViewLable(string str)
        {
            if (label1.InvokeRequired)
            {
                ViewLableDelegate wmd = new ViewLableDelegate(ViewLable);//应该是这样，楼上是我代码复制过来的，不好意思
                label1.Invoke(wmd, new string[] { str });
            }
            else
            {
                label1.Text = str;
            }
         }