C#等待所有子线程执行完毕方法

当我们在使用线程中，你会发现主线结束后子线程的结果才显示出来。现在我要等待所以子线程结束，然后在显示结果，怎么做呢？

方法如下：

1、使用 ManualResetEvent，代码如下： 

using System.Threading;

namespace ThreadStudy

{

    /// <summary>

    /// 等待所有子线程结束

    /// </summary>
    class StopAllWaitBySubThread

    {

        List<ManualResetEvent> manualEvents = new List<ManualResetEvent>();
        public void Main()

        {

            for (int i = 0; i < 5; i++)

            {

                ManualResetEvent mre = new ManualResetEvent(false);

                manualEvents.Add(mre);
                ThreadPool.QueueUserWorkItem(ThreadMethod, mre);

            }

            WaitHandle.WaitAll(manualEvents.ToArray());
            Console.WriteLine("Thread Finished!");

        }


        private void ThreadMethod(object obj)

        {

            //等待2秒，用于模拟系统在处理事情
            Thread.Sleep(2000);


            ManualResetEvent mre = (ManualResetEvent)obj;

            mre.Set();

            Console.WriteLine("Thread execute");

        }

    }
}

 此种方法线程中只传递了信号，那要传递参数怎么办？可以采用类，将信号放在类中来解决，代码如下。

 

using System.Threading;

namespace ThreadStudy

{

    /// <summary>

    /// 等待所有子线程结束

    /// </summary>
    class StopAllWaitBySubThread

    {

        List<ManualResetEvent> manualEvents = new List<ManualResetEvent>();
        public void Main()

        {

            for (int i = 0; i < 5; i++)

            {

                ManualResetEvent mre = new ManualResetEvent(false);

                manualEvents.Add(mre);

                Param pra = new Param();

                pra.mrEvent = mre;

                pra.praData = i;
                ThreadPool.QueueUserWorkItem(ThreadMethod, pra);

            }

            WaitHandle.WaitAll(manualEvents.ToArray());
            Console.WriteLine("Thread Finished!");

        }


        private void ThreadMethod(object obj)

        {

            Thread.Sleep(2000);

            Param pra = (Param)obj;

            pra.mrEvent.Set();

            Console.WriteLine("Thread execute at {0}", pra.praData);

        }

    }


    public class Param

    {

        public ManualResetEvent mrEvent;

        public int praData;

    }

}

 

2、判断线程数

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.Threading;

namespace ThreadStudy

{

    /// <summary>

    /// 判断当所有子线程执行完毕

    /// </summary>
    class ThreadPoolStop

    {

        public void Main()

        {

            for (int i = 0; i < 5; i++)

            {

                ThreadPool.QueueUserWorkItem(new WaitCallback(ThreadMethod), i);

            }

            int maxWorkerThreads, workerThreads;

            int portThreads;

            while (true)

            {

                /*

                 GetAvailableThreads()：检索由 GetMaxThreads 返回的线程池线程的最大数目和当前活动数目之间的差值。

                 而GetMaxThreads 检索可以同时处于活动状态的线程池请求的数目。

                 通过最大数目减可用数目就可以得到当前活动线程的数目，如果为零，那就说明没有活动线程，说明所有线程运行完毕。

                 */

                ThreadPool.GetMaxThreads(out maxWorkerThreads, out portThreads);

                ThreadPool.GetAvailableThreads(out workerThreads, out portThreads);

                if (maxWorkerThreads - workerThreads == 0)

                {

                    Console.WriteLine("Thread Finished!");

                    break;

                }

            }

        }


        private void ThreadMethod(object i)

        {
            //模拟程序运行
            Thread.Sleep((new Random().Next(1, 4)) * 1000);

            Console.WriteLine("Thread execute at {0}", i.ToString());

        }

    }

}

 

 3、使用Monitor 

using System.Threading;

namespace ThreadStudy

{

    class StopAllSubThread

    {

        int _ThreadCount = 5;

        int finishcount = 0;

        object locker = new object();

        public void Main()

        {

            for (int i = 0; i < _ThreadCount; i++)

            {

                Thread trd = new Thread(new ParameterizedThreadStart(ThreadMethod));

                trd.Start(i);

            }

            lock (locker)

            {

                while (finishcount != _ThreadCount)

                {

                    Monitor.Wait(locker);//等待
                }

            }

            Console.WriteLine("Thread Finished!");

        }


        private void ThreadMethod(object obj)

        {

            //模拟执行程序
            Thread.Sleep(3000);

            Console.WriteLine("Thread execute at {0}", obj.ToString());

            lock (locker)

            {

                finishcount++;

                Monitor.Pulse(locker); //完成，通知等待队列,告知已完，执行下一个。
            }

        }

    }

}

转载地址：http://www.cnblogs.com/scottckt/archive/2012/01/10/2317779.html