如何在C#线程中使用等待句柄？

Question

我的程序中有三个线程,我希望当线程一完成时它会向线程2发出信号以启动,当线程2完成时它应该通知线程3开始.

我怎么能实现这一点,我知道在C#中有等待句柄,但我不知道如何使用它们？

以下是我的程序代码:

class Program
    {
        static void Main(string[] args)
        {
            Thread t1 = new Thread(Task1);
            Thread t2 = new Thread(Task2);
            Thread t3 = new Thread(Task3);

            t1.Start();
            t2.Start();
            t3.Start();

            Console.Read();
        }

        public static void Task1()
        {
            Console.WriteLine("I am assigned task 1:");
            for (int i = 0; i < 50; i++)
            {
                Console.WriteLine("Task1" );
            }
        }
        public static void Task2()
        {
            Console.WriteLine("I am assigned task 2:");
            for (int i = 0; i < 50; i++)
            {
                Console.WriteLine("Task2");
            }
        }
        public static void Task3()
        {
            Console.WriteLine("I am assigned task 3:");
            for (int i = 0; i < 50; i++)
            {
                Console.WriteLine("Task3");
            }
        }
    }

Answer 1

您需要将事件传递给线程函数,这些函数指示每个事件完成时要发出什么信号以及在运行之前要等待的内容.看看下面的(未经测试的)代码,看看我的意思:

class Program
    {
        static void Main(string[] args)
        {
            Thread t1 = new Thread(Task1);
            ManualResetEvent e1=new ManualResetEvent(false);

            Thread t2 = new Thread(Task2);
            ManualResetEvent e2=new ManualResetEvent(false);

            Thread t3 = new Thread(Task3);
            ManualResetEvent e3=new ManualResetEvent(false);

            t1.Start(()=>Task1(e1));
            t2.Start(()=>Task2(e1,e2));
            t3.Start(()=>Task3(e2,e3);

            Console.Read();

            t1.Join();
            t2.Join();
            t3.Join();
        }

        public static void Task1(EventWaitHandle handle)
        {
            Console.WriteLine("I am assigned task 1:");
            for (int i = 0; i < 50; i++)
            {
                Console.WriteLine("Task1" );
            }
            handle.Set();

        }
        public static void Task2(EventWaitHandle waitFor, EventWaitHandle handle)
        {
            waitFor.WaitOne();

            Console.WriteLine("I am assigned task 2:");
            for (int i = 0; i < 50; i++)
            {
                Console.WriteLine("Task2");
            }

            handle.Set();
        }
        public static void Task3(EventWaitHandle waitFor, EventWaitHandle handle)
        {
            waitFor.WaitOne();

            Console.WriteLine("I am assigned task 3:");
            for (int i = 0; i < 50; i++)
            {
                Console.WriteLine("Task3");
            }

            handle.Set();
        }
    }