.NET并行计算和并发7-Task异步

使用任务并行库执行异步任务 下面的示例演示如何通过调用 TaskFactory.StartNew 方法来创建并使用 Task 对象。

 using System;
 using System.Threading;
 using System.Threading.Tasks;

 class Example
 {
     static void Main()
     {
         Action<object> action = (object obj) =>
         {
             Console.WriteLine("Task={0}, obj={1}, Thread={2}",
             Task.CurrentId, obj,
             Thread.CurrentThread.ManagedThreadId);
         };

         // Create a task but do not start it.
         Task t1 = new Task(action, "alpha");

         // Construct a started task
         Task t2 = Task.Factory.StartNew(action, "beta");
         // Block the main thread to demonstate that t2 is executing
         t2.Wait();

         // Launch t1
         t1.Start();
         Console.WriteLine("t1 has been launched. (Main Thread={0})",
                           Thread.CurrentThread.ManagedThreadId);
         // Wait for the task to finish.
         t1.Wait();

         // Construct a started task using Task.Run.
         String taskData = "delta";
         Task t3 = Task.Run(() =>
         {
             Console.WriteLine("Task={0}, obj={1}, Thread={2}",
                               Task.CurrentId, taskData,
                                Thread.CurrentThread.ManagedThreadId);
         });
         // Wait for the task to finish.
         t3.Wait();

         // Construct an unstarted task
         Task t4 = new Task(action, "gamma");
         // Run it synchronously
         t4.RunSynchronously();
         // Although the task was run synchronously, it is a good practice
         // to wait for it in the event exceptions were thrown by the task.
         t4.Wait();
     }
 }
 // The example displays output like the following:
 //       Task=1, obj=beta, Thread=3
 //       t1 has been launched. (Main Thread=1)
 //       Task=2, obj=alpha, Thread=4
 //       Task=3, obj=delta, Thread=3
 //       Task=4, obj=gamma, Thread=1