C#-WinForm跨线程修改UI界面的示例

private delegate void SetLabelDelegate(string value);

    private delegate void SetLabelDelegate2(string value);

    private void SetText(string value)
    {
      if (this.InvokeRequired)
      {
        SetLabelDelegate d = new SetLabelDelegate(SetText);
        this.Invoke(d, new object[] { value });
      }
      else
      {
        txtbigcrmresult.Text = value.ToString() + txtbigcrmresult.Text;
      }
    }

private void button3_Click(object sender, EventArgs e)
    {
      ThreadPool.QueueUserWorkItem(new WaitCallback(dao), "test");
    }
 private void dao(object url)
    {
      IDbConnection conn = new SqlConnection(txtbigcrmui.Text);
      SetText("\r\n" + "start");
     .........................
      SetText("\r\n" + "end");
    }

 SetText("\r\n" + "start");