Thread.Join

Thread.Join

MSDN解释为：使用此方法确保线程已终止。如果线程不终止，则调用方将无限期阻塞。如果调用 Join 时该线程已终止，此方法将立即返回。

如下边这个例子，

  static void Main()
        {            
            // Create the worker thread object. This does not start the thread.            
            Thread workerThread = new Thread(workMethod);
            
            // Start the worker thread.
            workerThread.Start();                 
            workerThread.Join();
            Console.WriteLine("Main thread: worker thread has terminated.");
            Console.Read();
        }
        static void workMethod()
        {
            Console.WriteLine("Work thread:start sleep");
            Thread.Sleep(1000);
            Console.WriteLine("Work thread:finished sleep 1000");
        }

输出结果为：

如果去掉第8行，workerThread.Join(); 则输出结果为：

因为主线程中在workthread启动后的代码会直接执行完，而如果有workerThread.Join();则会将主线程中的剩余代码阻断，直到workerThread执行完后再继续执行