backgroundworker问题

[faoyy]

我想实现在界面上实时更新一个label的值，用for循环100000此，用的backgroundworker方法和线程+委托的两种方法：

//BackgroundWorker
        DateTime now;
        TimeSpan ts;
        private void button3_Click(object sender, EventArgs e)
        {
            if (backgroundWorker1.IsBusy)
                return;
            now = DateTime.Now;
            backgroundWorker1.RunWorkerAsync();
        }

        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            BackgroundWorker bw = sender as BackgroundWorker;
            for (int i = 0; i < 100000; i++)
            {
                bw.ReportProgress(i,100000);
                Thread.Sleep(1);            }
        }

        private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            label3.Text = e.ProgressPercentage.ToString();
            progressBar3.Value = e.ProgressPercentage / 1000;
        }

        private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            progressBar3.Value = 100;
            ts = DateTime.Now - now;
            MessageBox.Show("BackgroundWorker："+ts.TotalMilliseconds);
        }
 //線程+委託
        private void button2_Click(object sender, EventArgs e)
        {
            Thread th = new Thread(new ThreadStart(ShowNum));
            th.Start();
        }
        public delegate void  UpdateText(int i);

        public void UpdateTextLabel(int i)
        {
            if (label2.InvokeRequired)
            {
                UpdateText ut = new UpdateText(UpdateTextLabel);
                label2.Invoke(ut, i);
            }
            else
            {
                label2.Text = i.ToString();
                progressBar2.Value = i / 1000;
            }
        }

        public void ShowNum()
        {
            DateTime now = DateTime.Now;
            for(int i =0;i< 100000;i++)
            {
                UpdateTextLabel(i);
            }
            DateTime now1 = DateTime.Now;
            TimeSpan ts = now1 - now;
            MessageBox.Show("線程+委託：" + ts.TotalMilliseconds);
        }

我想问得时为什么在backgroundworker中用加入sleep，最初我没加，结果label没有实时更新，加了以后达到效果，但是速度变慢了，而线程+委托方法，速度快，但是cpu占用率却很高，谁能帮我解答一下这些问题

[faoyy]

来人帮帮忙呀

[卧_槽]

建议直接用timer

[faoyy]

我就是想弄个小程序然后搞懂多线程，并不是只要结果，但还是谢谢你回答