private void button1_Click(object sender, EventArgs e) { int num = 1; while (true) { this.textBox1.Text = num.ToString(); //刷新界面 this.textBox1.Update(); //暂停线程一定时间让眼睛看清楚 System.Threading.Thread.Sleep(200); num++; if (num > 5) { break; } } }