Task多线程

Task多线程

 1.首先是我们线程之间的启动。

 1.这样

    Task task = new Task(()=>
            {
                //
                System.Threading.Thread.Sleep(500);
                Console.WriteLine("do something....");
                //匿名函数，
                //还要其他的一些东邪；
            });
            task.Start();

2.或则这样

 Task t=Task.Run(()=> { Console.WriteLine("直接我就开始run了..."); });

3.再或则这样

  static void DoSomething()
        {
            System.Threading.Thread.Sleep(500);
            Console.WriteLine("do something..static");

        }
        static void Main(string[] args)
        {
            Task t1 = new Task(DoSomething);
            t1.Start(); //这样我们就启动的落地呀；

            
            Console.WriteLine("I am main thread line");
            Console.ReadLine();
        }

4.这样

  Task task = Task.Factory.StartNew(() => { Console.WriteLine("这样,直接使用的Task.Factory.StartNew"); });

  TaskFactory tf = new TaskFactory();
  Task t1 = tf.StartNew(() => { Console.WriteLine("再或则这样..."); });

总结：大概就是两种方式；构造函数和我们的factory；

1.等待任务的完成并获取返回值，这个就是我们简单的基本操作；

            Task<int> task = new Task<int>(() => {
                int sum = 0;
                Console.WriteLine("fucking life...");
                for (int i = 0; i < 100; i++)
                {
                    sum += i;
                }
                return sum;
            });
            task.Start();
            task.Wait();
            var result = task.Result.ToString();
            Console.WriteLine("result is "+task.Result.ToString());
            Console.WriteLine("I am main thread line");
            Console.ReadLine();

2.ContinueWith方法在任务完成时启动一个新任务

 Task<int> task = new Task<int>(() => {
                System.Threading.Thread.Sleep(600);
                int sum = 0;
                Console.WriteLine("fucking life...");
                for (int i = 0; i < 100; i++)
                {
                    sum += i;
                }
                return sum;
            });
            task.Start();
            Console.WriteLine("主线程，执行其他任务...");
            
            Task hoop=task.ContinueWith(t=>{
                Console.WriteLine("任务执行完之后的结果是：{0}",t.Result.ToString());
            });

            Console.WriteLine("I am main thread line");
            Console.ReadLine();

Task 的生命周期；

            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();  //用来主阻塞线程，
            Console.WriteLine("after finissh："+task1.Status);

从我们可以得出Task的简略生命周期：

Created：表示默认初始化任务，但是“工厂创建的”实例直接跳过。

WaitingToRun: 这种状态表示等待任务调度器分配线程给任务执行。

RanToCompletion：任务执行完毕。

Task 流程的控制

 var task1 = new Task(() =>
              {
                  Console.WriteLine("task 1 begin");
                  System.Threading.Thread.Sleep(2000);
                  Console.WriteLine("task 1 finished");
              });

            var task2 = new Task(() =>
            {
                Console.WriteLine("task 2 begin");
                System.Threading.Thread.Sleep(2000);
                Console.WriteLine("task 2 finished");
            });


            var task3 = new Task(() =>
            {
                Console.WriteLine("task 3 begin");
                System.Threading.Thread.Sleep(2000);
                Console.WriteLine("task 3 finished");
            });

            task1.Start();
            task2.Start();
            task3.Start();

            Task.WaitAll(task1, task2, task3);  //他它接受数组类型的task的使用地呀；
            Console.WriteLine("All task has finished");


            Console.ReadLine();

 Ps： Task.WaitAny

这个用发同Task.WaitAll，就是等待任何一个任务完成就继续向下执行，将上面的代码WaitAll替换为WaitAny，输出结果如下：

 ContinueWith的用法。

            var task1 = new Task(() =>
              {
                  Console.WriteLine("task 1 begin");
                  System.Threading.Thread.Sleep(500);
                  Console.WriteLine("task 1 finished");
              });


            task1.Start();
            var result = task1.ContinueWith<string>(t=> {

                Console.WriteLine("task1 finished ");
                return "continue task finish.....";
            });

//在每次调用ContinueWith方法时，每次会把上次Task的引用传入进来，以便检测上次Task的状态，
            var send = Task.Factory.StartNew(() => { Console.WriteLine("fuck life.."); })
                .ContinueWith<bool>(s => { if (1 == 1) return false; })
                .ContinueWith<string>(r =>
                {
                    if (r.Result)
                    {
                        return "Finished";  //可以获取上一个流程task 中的值
                    }
                    else
                    {
                        return "Error";
                    }

                });
            Console.WriteLine(send.Result);

            

Task的取消

    

var tokenSource = new CancellationTokenSource();
            var token = tokenSource.Token;
            Console.WriteLine(token.ToString());

            var task = Task.Factory.StartNew(() =>
              {
                  for (var i = 0; i < 1000; i++)
                  {
                      System.Threading.Thread.Sleep(1000);
                      Console.WriteLine("proceeed mission...");
                      if (token.IsCancellationRequested)
                      {
                          Console.WriteLine("Abort mssion sucess!");
                          //这里也采用轮循的方式....
                          return;
                      }
                  }

              },token);

            token.Register(() =>
            {
                Console.WriteLine("Cancle task....");
            });

            Console.WriteLine("press enter to cancle task...");
            Console.ReadKey();
            tokenSource.Cancel();

            Console.ReadLine();

 这里还有一篇较好的文章：http://www.cnblogs.com/jesse2013/p/async-and-await.html