多线程系列 线程池ThreadPool

　上一篇文章我们总结了多线程最基础的知识点Thread，我们知道了如何开启一个新的异步线程去做一些事情。可是当我们要开启很多线程的时候，如果仍然使用Thread我们需要去管理每一个线程的启动，挂起和终止，显然是很麻烦的一件事情。还好.net framework为我们提供了线程池ThreadPool来帮助我们来管理这些线程，这样我们就不再需要手动地去终止这些线程。这一篇文章就让我们来学习一下线程池ThreadPool吧。关于它我想从以下几个方面进行总结。

1. 认识线程池ThreadPool
2. ThreadPool的用法

认识线程池ThreadPool

ThreadPool类是一个静态类，你不能也不必要生成它的对象。而且一旦使用该方法在线程池中添加了一个项目，那么该项目是无法取消的。这里你无需自己建立线程，我们只需要把要做的工作写成函数，然后作为参数传递给ThreadPool.QueueUserWorkItem()方法就行了，传递的方法是依靠WaitCallBack代理对象，而线程的建立，管理和运行等工作都是由系统自动完成的，你无须考虑那些复杂的细节问题了。

ThreadPool的用法

我现在在之前的例子的基础上，使用线程池ThreadPool来实现。代码如下。

namespace ThreadDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            // 使用ThreadPool实现
            Fish fish1 = new Fish { Name = "小黄鱼" };
            Fish fish2 = new Fish { Name = "大鲨鱼" };
            Fish fish3 = new Fish { Name = "灯笼鱼" };
            Fish fish4 = new Fish { Name = "红鲤鱼" };
            Fish fish5 = new Fish { Name = "灯笼鱼" };
            ThreadPool.QueueUserWorkItem(f => { fish1.Move(); }); //lambda表达式
            ThreadPool.QueueUserWorkItem(f => { fish2.Move(); });
            ThreadPool.QueueUserWorkItem(f => { fish3.Move(); });
            ThreadPool.QueueUserWorkItem(f => { fish4.Move(); });
            ThreadPool.QueueUserWorkItem(f => { fish5.Move(); });

            Console.ReadKey();
        }
    }

    /// <summary>
    /// 鱼
    /// </summary>
    public class Fish
    {
        public string Name { get; set; }

        public int Score { get; set; }

        public Fish()
        {
        }

        public void Move()
        {
            Console.WriteLine(string.Format("{0}在游来游去...", Name));
        }
    }
}

程序运行结果如下。

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" alt="" />

eg2:

说明：将方法排入队列以便执行，WaitCallback，表示要执行的方法。如果将方法成功排入队列，则为 true；否则为 false。

示例：addtest方法需要比较长的时间来响应，因此在button1_Click被点击以后，程序会失去响应，使用ThreadPool.QueueUserWorkItem 后，页面会继续响应其他时间，等addtest执行结束后，响应结果。

<Window x:Class="WpfAppThread.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window1" Height="300" Width="300">
    <Grid>
        <Button Height="23" HorizontalAlignment="Left" Margin="9,23,0,0" Name="button1" VerticalAlignment="Top" Width="75" Click="button1_Click">ButtonOne</Button>
        <Button Height="23" Margin="102,23,101,0" Name="button2" VerticalAlignment="Top" Click="button2_Click">ButtonTwo</Button>
    </Grid>
</Window>

        private void button1_Click(object sender, RoutedEventArgs e)
        {
            ThreadPool.QueueUserWorkItem(new WaitCallback(addtest),"Testaa"); 
            //addtest();
        }

private void addtest(object aa)
        {
            long result=0;
            for (int i = 0; i < 1000000000; i++)
            {
                result += i;
            }
            MessageBox.Show(result.ToString()+aa.ToString());
            
        }

private void button2_Click(object sender, RoutedEventArgs e)
        {
            MessageBox.Show("two");
        }