C#使用Task来执行线程

对于多线程，我们经常使用的是Thread。在我们了解Task之前，如果我们要使用多核的功能可能就会自己来开线程，然而这种线程模型在.net 4.0之后被一种称为基于“任务的编程模型”所冲击，因为task会比thread具有更小的性能开销，不过大家肯定会有疑惑，任务和线程到底有什么区别呢？

Task和Thread的区别

• Task是架构在Thread之上的，也就是说任务最终还是要抛给线程去执行。
• Task跟Thread不是一对一的关系，比如开10个任务并不是说会开10个线程，这一点任务有点类似线程池，但是任务相比线程池有很小的开销和精确的控制。

Task控制台测试程序

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

namespace MyTask
{
    class Program
    {
        /// <summary>
        /// 启动方式
        /// </summary>
        public static void StartWay()
        {
            var task1 = new Task(() =>
            {
                Console.WriteLine("Hello,task");
            });
            task1.Start();

            var task2 = Task.Factory.StartNew(() =>
            {
                Console.WriteLine("Hello,task started by task factory");
            });
        }

        /// <summary>
        /// 生命周期测试
        /// </summary>
        public static void LifeCircle()
        {
            var task1 = new Task(() =>
            {
                Console.WriteLine("Begin");
                System.Threading.Thread.Sleep(2000);
                Console.WriteLine("Finish");
            });
            Console.WriteLine("Before start:" + task1.Status);
            task1.Start();
            Console.WriteLine("After start:" + task1.Status);
            task1.Wait();
            Console.WriteLine("After Finish:" + task1.Status);

        }

        /// <summary>
        /// 等待所有任务完成
        /// </summary>
        public static void WaitAll()
        {
            var task1 = new Task(() =>
            {
                Console.WriteLine("Task 1 Begin");
                System.Threading.Thread.Sleep(2000);
                Console.WriteLine("Task 1 Finish");
            });
            var task2 = new Task(() =>
            {
                Console.WriteLine("Task 2 Begin");
                System.Threading.Thread.Sleep(3000);
                Console.WriteLine("Task 2 Finish");
            });

            task1.Start();
            task2.Start();
            Task.WaitAll(task1, task2);
            Console.WriteLine("WaitAll task finished!");

        }

        /// <summary>
        /// 等待任意一个执行任务完成
        /// </summary>
        public static void WaitAny()
        {
            var task1 = new Task(() =>
            {
                Console.WriteLine("Task 1 Begin");
                System.Threading.Thread.Sleep(2000);
                Console.WriteLine("Task 1 Finish");
            });
            var task2 = new Task(() =>
            {
                Console.WriteLine("Task 2 Begin");
                System.Threading.Thread.Sleep(3000);
                Console.WriteLine("Task 2 Finish");
            });

            task1.Start();
            task2.Start();
            Task.WaitAny(task1, task2);
            Console.WriteLine("WaitAny task finished!");
        }

        /// <summary>
        /// 任务回调方法
        /// </summary>
        public static void ContinueWith()
        {
            var task1 = new Task(() =>
            {
                Console.WriteLine("Task 1 Begin");
                System.Threading.Thread.Sleep(2000);
                Console.WriteLine("Task 1 Finish");
            });
            var task2 = new Task(() =>
            {
                Console.WriteLine("Task 2 Begin");
                System.Threading.Thread.Sleep(3000);
                Console.WriteLine("Task 2 Finish");
            });


            task1.Start();
            task2.Start();
            var result = task1.ContinueWith<string>(task =>
            {
                Console.WriteLine("task1 finished!");
                return "This is task1 result!";
            });

            Console.WriteLine(result.Result.ToString());

            var result2 = task2.ContinueWith<string>(task =>
            {
                Console.WriteLine("task2 finished!");
                return "This is task2 result!";
            });

            Console.WriteLine(result2.Result.ToString());
        }

        /// <summary>
        /// 取消任务
        /// </summary>
        public static void Cancel()
        {
            var tokenSource = new CancellationTokenSource();
            var token = tokenSource.Token;
            var task = Task.Factory.StartNew(() =>
            {
                for (var i = 0; i < 1000; i++)
                {
                    System.Threading.Thread.Sleep(1000);
                    if (token.IsCancellationRequested)
                    {
                        Console.WriteLine("Abort mission success!");
                        return;
                    }
                }
            }, token);
            token.Register(() =>
            {
                Console.WriteLine("Canceled");
            });
            Console.WriteLine("Press enter to cancel task...");
            Console.ReadKey();
            tokenSource.Cancel();

            Console.ReadKey();//这句忘了加，程序退出了，看不到“Abort mission success!“这个提示
        }

        /// <summary>
        /// 函数入口
        /// </summary>
        /// <param name="args"></param>
        static void Main(string[] args)
        {
            Console.WriteLine("StartWay is runing");
            StartWay();
            Console.WriteLine("LifeCircle is runing");
            LifeCircle();
            Console.WriteLine("WaitAll is runing");
            WaitAll();
            Console.WriteLine("WaitAny is runing");
            WaitAny();
            Console.WriteLine("ContinueWith is runing");
            ContinueWith();
            Console.WriteLine("Cancel is runing");
            Cancel();

            Console.Read();
        }
    }
}

参考地址： http://www.cnblogs.com/yunfeifei/p/4106318.html