C# Task类 笔记

运行

namespace Example{    class MyApplication    {        public static void Main()        {            Task t = Task.Run(() =>              {                  for (int i = 0; i < 100; i++)                      Console.WriteLine(i);              });            t.Wait();        }    }}

返回一个值

namespace Example{    class MyApplication    {        public static void Main()        {            Task<int> t = Task.Run(() =>              {                  return 40;              });            Console.WriteLine(t.Result);   //输出40        }    }}

ContinueWith

namespace Example{    class MyApplication    {        public static void Main()        {            Task<int> t = Task.Run(() =>              {                  return 40;              });            t.ContinueWith((i) =>            {                Console.WriteLine("Canceled");            }, TaskContinuationOptions.OnlyOnCanceled);            t.ContinueWith((i) =>            {                Console.WriteLine("Faulted");            }, TaskContinuationOptions.OnlyOnFaulted);            var completedtask=t.ContinueWith((i) =>            {                Console.WriteLine("Completed");            }, TaskContinuationOptions.OnlyOnRanToCompletion);            completedtask.Wait();            Console.WriteLine(t.Result);         }    }}

父线程将会在子线程结束后结束

namespace Example{    class MyApplication    {        public static void Main()        {            Task<Int32[]> parent = Task.Run(() =>               {                   var result = new Int32[3];                   new Task(() => result[0] = 0, TaskCreationOptions.AttachedToParent).Start();                   new Task(() => result[1] = 1, TaskCreationOptions.AttachedToParent).Start();                   new Task(() => result[2] = 2, TaskCreationOptions.AttachedToParent).Start();                   return result;               });            var finalTask = parent.ContinueWith(parentTask =>            {                foreach (int i in parentTask.Result)                {                    Console.WriteLine(i);                }            });            finalTask.Wait();        }    }}

使用TaskFactory

namespace Example{    class MyApplication    {        public static void Main()        {            Task<Int32[]> parent = Task.Run(() =>               {                   var result = new Int32[3];                   TaskFactory tf = new TaskFactory(TaskCreationOptions.AttachedToParent, TaskContinuationOptions.ExecuteSynchronously);                   tf.StartNew(() => result[0] = 0);                   tf.StartNew(() => result[1] = 1);                   tf.StartNew(() => result[2] = 2);                   return result;               });            var finalTask = parent.ContinueWith(parentTask =>            {                foreach (int i in parentTask.Result)                {                    Console.WriteLine(i);                }            });            finalTask.Wait();        }    }}

Task.WaitAlL 等待提供的所有 Task 对象完成执行过程。

Task.WaitAny 等待提供的任何 Task 对象完成执行过程。