线程的优先级

//线程是靠CPU时间片来运行的，哪个线程抢的时间片多，他就执行的快。线程的优先级表示线程抢CPU时间片的能力大小。

 以下例子，简单描述了优先级的作用，但效果不是十分明显，偶尔还会效果相反。

 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Threading;

namespace WindowsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private void button1_Click(object sender, EventArgs e)
        {
            PriortyTest work = new PriortyTest(this);

            //创建线程并设置线程执行方法
            Thread threadOne = new Thread(new ThreadStart(work.ThreadMethod));
            threadOne.Name = "线程1";
            Thread threadTwo = new Thread(new ThreadStart(work.ThreadMethod));
            threadTwo.Name = "线程2";

            //设置优先级 这个例子最关健的代码。
            threadOne.Priority = ThreadPriority.Highest; //抢CPU时间的能力强，数的数就多一些
            threadTwo.Priority = ThreadPriority.BelowNormal;

            threadOne.Start();
            threadTwo.Start();

            //让两个线程都计算1秒钟
            Thread.Sleep(1000);

            //停止计算
            work.LoopSwitch = false;
        }
    }


    /// <summary>
    /// 优先级测试类
    /// </summary>
    public class PriortyTest
    {
        //用来控制while循环，为false就退出while循环
        bool loopSwithch;

        Form1 main = null;
        //构造方法
        public PriortyTest(Form1 _main)
        {
            main = _main;
            loopSwithch = true;
        }

        /// <summary>
        /// 设置循环开关属性
        /// </summary>
        public bool LoopSwitch
        {
            set { loopSwithch = value; }
        }

        /// <summary>
        /// 数数方法，并显示出来
        /// </summary>
        public void ThreadMethod()
        {
            long threadCount = 0;

            //进行累加操作
            while (loopSwithch) { threadCount++; }

            //结束记数后，显示数到多少了。
            show(threadCount.ToString(), Thread.CurrentThread.Name);
        }

        /// <summary>
        ///  向主界面richTextBox1显示信息,
        /// </summary>
        /// <param name="message">要显示的信息</param>
        /// <param name="threadname">当前线程的名字</param>

        private void show(string message, string threadname)
        {
            //richTextBox1控件的Modifiers属性要设为Public，这样才可以调用的到
            main.richTextBox1.Invoke(new EventHandler(delegate
            {
                if (main.richTextBox1.Text.Length > 5069) main.richTextBox1.Clear();
                main.richTextBox1.Text += threadname + ":" + message + Environment.NewLine;
                main.richTextBox1.Select(main.richTextBox1.Text.Length, 0);
                main.richTextBox1.ScrollToCaret();
            }));
        }
    }
}