List arr = new List();for (int i =0; i <90; i=i+5) //循环创建线程{Thread myThread =new Thread(delegate() {catchdate(i,key);});myThread.Start();arr.Add(myThread);}foreach(Thread t in arr){while(t.IsAlive){Thread.Sleep(10);}}// 走到这里,所有线程都结束了,哈哈