C#延时

using (var bg = new BackgroundWorker())
{
 bg.DoWork += delegate { System.Threading.Thread.Sleep(5000); }; // 启用一个线程等待 5 秒
 bg.RunWorkerCompleted += delegate { MessageBox.Show("Hello!"); }; // 线程执行完成后会执行 RunWorkerCompleted 事伯的代码块
 bg.RunWorkerAsync();
}