程序Ⅰ：通过Task类创建新线程
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using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading;using System.Threading.Tasks;namespace Test000{ class Program { /// <summary> /// Task类封装 /// </summary> class MyTask { /// <summary> /// 第一个Task类，每秒计数，计数5次 /// </summary> public static void T1() { Console.WriteLine("Task #{0}: Begin!", Task.CurrentId); for (int i = 0; i < 5; i++) { Thread.Sleep(1000); Console.WriteLine("Task #{0}: {1}", Task.CurrentId, i); } Console.WriteLine("Task #{0}: Terminated!", Task.CurrentId); } /// <summary> /// 第二个Task类，每秒计数，计数5次 /// </summary> public static void T2() { Console.WriteLine("Task #{0}: Begin!", Task.CurrentId); Thread.Sleep(500); for (int i = 0; i < 5; i++) { Thread.Sleep(1000); Console.WriteLine("Task #{0}: {1}", Task.CurrentId, i); } Console.WriteLine("Task #{0}: Terminated!", Task.CurrentId); } } static void Main(string[] args) { //建立两个Task Task tsk1 = new Task(MyTask.T1); Console.WriteLine("Task #{0}: Constructed!", tsk1.Id); Task tsk2 = new Task(MyTask.T2); Console.WriteLine("Task #{0}: Constructed!", tsk1.Id); //运行Task tsk1.Start(); tsk2.Start(); //等待Task运行结束 WaitAll(tsk1, tsk2); Console.ReadLine(); } /// <summary> /// 等待所有的Task运行结束 /// </summary> /// <param name="tsks">等待的Task类</param> public static void WaitAll(params Task[] tsks) { foreach (var t in tsks) { t.Wait(); } } }} |
运行结果
程序Ⅱ：通过TaskFactory启动任务并接收任务的返回值
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using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace Test001{ class Program { /// <summary> /// Task类封装 /// </summary> class MyTask { /// <summary> /// 求1+2+...+n的和 /// </summary> /// <param name="n">数n</param> /// <returns></returns> public static int Sum(object n) { int x = (int)n; int sum = 0; for (int i = 1; i <= x; i++) { sum += i; } return sum; } } static void Main(string[] args) { Task<int> tsk = Task<int>.Factory.StartNew(MyTask.Sum, 100); Console.WriteLine("Result is: " + tsk.Result); Console.ReadLine(); } }} |
运行结果
程序Ⅲ：通过Parallel类的Invoke函数，并行调用多个Task
本程序中通过Lambda表达式来建立新的Task
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using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading;using System.Threading.Tasks;namespace Test002{ class Program { static void Main(string[] args) { Parallel.Invoke ( () => { Console.WriteLine("Task #{0}: Begin!", Task.CurrentId); for (int i = 0; i < 5; i++) { Thread.Sleep(1000); Console.WriteLine("Task #{0}: {1}", Task.CurrentId, i); } Console.WriteLine("Task #{0}: Terminated!", Task.CurrentId); }, () => { Console.WriteLine("Task #{0}: Begin!", Task.CurrentId); Thread.Sleep(500); for (int i = 0; i < 5; i++) { Thread.Sleep(1000); Console.WriteLine("Task #{0}: {1}", Task.CurrentId, i); } Console.WriteLine("Task #{0}: Terminated!", Task.CurrentId); } ); Console.ReadLine(); } }} |
运行结果
程序Ⅳ：通过Parallel类的For和FoeEach函数，并行调用多个Task
本程序中，通过Stopwatch类统计程序段的运行时间
从例中可以看出：不是所有的循环在并行化时都是有效的。通常，对于小型循环或执行非常简单的操作的循环来说，使用顺序循环比并行循环更加快速
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using System;using System.Collections.Generic;using System.Diagnostics;using System.Linq;using System.Text;using System.Threading.Tasks;namespace Test003{ class Program { /// <summary> /// 示例函数 /// </summary> /// <param name="n">参数</param> public static void DoSomeThing(int n) { int sum = 0; for (int i = 0; i < n * 100; i++) { sum += i; } } static void Main(string[] args) { //计时工具，需要System.Diagnostics Stopwatch sw = new Stopwatch(); //统计依次顺序调用函数的时间 sw.Start(); for (int i = 100; i < 105; i++) { DoSomeThing(100); } sw.Stop(); Console.WriteLine("TotalTime: {0}", sw.Elapsed.TotalMilliseconds); sw.Reset(); Console.WriteLine("==========="); //统计并行调用函数的时间 sw.Start(); Parallel.For(100, 105, DoSomeThing); sw.Stop(); Console.WriteLine("TotalTime: {0}", sw.Elapsed.TotalMilliseconds); sw.Reset(); Console.WriteLine("==========="); //统计并行调用函数的时间 sw.Start(); Parallel.ForEach(new int[5] { 100, 101, 102, 103, 104 }, DoSomeThing); sw.Stop(); Console.WriteLine("TotalTime: {0}", sw.Elapsed.TotalMilliseconds); sw.Reset(); Console.ReadLine(); } }} |
运行结果
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