c# - 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 1 完成时，它会通知线程 2 启动，而当线程 2 完成时，它会通知线程 3 启动。

我怎样才能做到这一点，我知道在 C# 中有等待句柄可以做到这一点，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

您需要将事件传递到线程函数中，以指示在每个函数完成时发出什么信号以及在它们运行之前要等待什么。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();
        }
    }