组合任务

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

namespace Test
{
    class Program
    {

        /// <summary>
        /// 组合任务
        /// </summary>
        static void Main()
        {
            CurrentThreadInfo("主线程Main()的");

            Task<int> task1 = new Task<int>(() => TaskMethod("task11"));
            Task<int> task2 = new Task<int>(() => TaskMethod("task22"));

            //
            task1.ContinueWith(t1 => Console.WriteLine("任务task1执行成功返回值：{0} -线程Id:{1}  - {2}", t1.Result, t1.Id, DateTime.Now.ToString()), TaskContinuationOptions.OnlyOnRanToCompletion);

            task1.ContinueWith(t1 => Console.WriteLine("任务task1执行失败时返回的信息,线程Id:{0}", t1.Id), TaskContinuationOptions.OnlyOnFaulted);

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


            Console.WriteLine("休眠3秒");
            Thread.Sleep(TimeSpan.FromMilliseconds(3000));


            Task task2Continue = task2.ContinueWith(t2 => Console.WriteLine("任务task2执行成功返回值：{0} , 线程Id:{1} , {2}", t2.Result, t2.Id, DateTime.Now.ToString()), TaskContinuationOptions.NotOnRanToCompletion | TaskContinuationOptions.ExecuteSynchronously);
            //TaskContinuationOptions.ExecuteSynchronously选项,尝试同步执行该后续操作。 

            task2Continue.GetAwaiter().OnCompleted(() => Console.WriteLine("线程Id:{0},是否后台线程:{1}", Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsBackground));


            Console.WriteLine("再休眠3秒");
            Thread.Sleep(TimeSpan.FromMilliseconds(3000));


            Task taskFinally = new Task<int>(() =>
            {
                //创建一个新任务,当运行该任务时,通过TaskCreationOptions.AttachedToParent选项来运行一个子任务。
                //子任务必须在父任务运行时创建,并正确的附加给父任务。
                var innerTask = Task.Factory.StartNew(() => TaskMethod("innerTask"), TaskCreationOptions.AttachedToParent);

                innerTask.ContinueWith(t => TaskMethod("innerTaskContinue"), TaskContinuationOptions.AttachedToParent);
                //只有所有子任务结束工作,父任务才会完成。
                //通过提供一个TaskContinuationOptions.AttachedToParent选项也可以在子任务上运行后续操作。
                //该后续操作也会影响父任务,并且直到最后一个子任务结束,它才会运行完成。

                return TaskMethod("taskFinally返回值");
            });

            taskFinally.Start();

            while (taskFinally.IsCompleted == false)
            {
                Console.WriteLine("taskFinally的线程状态：{0}", taskFinally.Status.ToString());
                Thread.Sleep(500);
            }


            Console.WriteLine("\n执行完成");
            Console.ReadLine();
        }

        private static int TaskMethod(string name)
        {
            Console.WriteLine("任务名称：{0} , {1}", name, DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"));
            CurrentThreadInfo(name);

            Thread.Sleep(TimeSpan.FromMilliseconds(2000));
            return Thread.CurrentThread.ManagedThreadId;
        }


        /// <summary>
        /// 当前线程信息
        /// </summary>
        private static void CurrentThreadInfo(string name)
        {
            StringBuilder builder = new StringBuilder();
            builder.AppendLine("");
            builder.AppendLine(String.Format("{0}线程Id:\t\t{1}", name, Thread.CurrentThread.ManagedThreadId));
            builder.AppendLine(String.Format("{0}是否使用线程池:\t{1}", name, Thread.CurrentThread.IsThreadPoolThread));
            builder.AppendLine(String.Format("{0}是否后台线程:\t{1}", name, Thread.CurrentThread.IsBackground));
            builder.AppendLine(String.Format("{0}线程状态:\t\t{1}", name, Thread.CurrentThread.ThreadState.ToString()));
            builder.AppendLine(String.Format("{0}当前时间:\t\t{1}", name, DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")));
            builder.AppendLine("");

            Console.WriteLine(builder.ToString());
        }
    }
}

 

打印运行结果：

/*

主线程Main()的线程Id:           8
主线程Main()的是否使用线程池:    False
主线程Main()的是否后台线程:      False
主线程Main()的线程状态:         Running
主线程Main()的当前时间:         2016-08-28 19:19:50


休眠3秒
任务名称：task11 , 2016-08-28 19:19:50
任务名称：task22 , 2016-08-28 19:19:50

task22线程Id:           10
task22是否使用线程池:    True
task22是否后台线程:      True
task22线程状态:         Background
task22当前时间:         2016-08-28 19:19:50


task11线程Id:           9
task11是否使用线程池:    True
task11是否后台线程:      True
task11线程状态:         Background
task11当前时间:         2016-08-28 19:19:50


任务task1执行成功返回值：9 -线程Id:2  - 2016/8/28 19:19:52
再休眠3秒
线程Id:12,是否后台线程:True
taskFinally的线程状态：WaitingToRun
任务名称：innerTask , 2016-08-28 19:19:56

innerTask线程Id:                11
innerTask是否使用线程池:         True
innerTask是否后台线程:           True
innerTask线程状态:              Background
innerTask当前时间:              2016-08-28 19:19:56


任务名称：taskFinally返回值 , 2016-08-28 19:19:56

taskFinally返回值线程Id:                12
taskFinally返回值是否使用线程池:         True
taskFinally返回值是否后台线程:           True
taskFinally返回值线程状态:              Background
taskFinally返回值当前时间:              2016-08-28 19:19:56


taskFinally的线程状态：Running
taskFinally的线程状态：Running
taskFinally的线程状态：Running
任务名称：innerTaskContinue , 2016-08-28 19:19:58

innerTaskContinue线程Id:                9
innerTaskContinue是否使用线程池:         True
innerTaskContinue是否后台线程:           True
innerTaskContinue线程状态:              Background
innerTaskContinue当前时间:              2016-08-28 19:19:58


taskFinally的线程状态：WaitingForChildrenToComplete
taskFinally的线程状态：WaitingForChildrenToComplete
taskFinally的线程状态：WaitingForChildrenToComplete
taskFinally的线程状态：WaitingForChildrenToComplete

执行完成
 
*/