C# Task的用法详解 z

1、Task的优势
　　ThreadPool相比Thread来说具备了很多优势，但是ThreadPool却又存在一些使用上的不方便。比如：
　　◆ ThreadPool不支持线程的取消、完成、失败通知等交互性操作；
　　◆ ThreadPool不支持线程执行的先后次序；
　　以往，如果开发者要实现上述功能，需要完成很多额外的工作，现在，FCL中提供了一个功能更强大的概念：Task。Task在线程池的基础上进行了优化，并提供了更多的API。在FCL4.0中，如果我们要编写多线程程序，Task显然已经优于传统的方式。

2、Task的用法
　　2.1、创建任务
　　无返回值的方式
　　方式1:
　　var t1 = new Task(() => TaskMethod("Task 1"));
　　t1.Start();
　　Task.WaitAll(t1);//等待所有任务结束
　　注:
　　任务的状态:
　　Start之前为:Created
　　Start之后为:WaitingToRun

　　方式2:
　　Task.Run(() => TaskMethod("Task 2"));

　　方式3:
　　Task.Factory.StartNew(() => TaskMethod("Task 3")); 直接异步的方法
　　或者
　　var t3=Task.Factory.StartNew(() => TaskMethod("Task 3"));
　　Task.WaitAll(t3);//等待所有任务结束
　　注:
　　任务的状态:
　　Start之前为:Running
　　Start之后为:Running

using System;
using System.Threading;
using System.Threading.Tasks;
 
namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            var t1 = new Task(() => TaskMethod("Task 1"));
            var t2 = new Task(() => TaskMethod("Task 2"));
            t2.Start();
            t1.Start();
            Task.WaitAll(t1, t2);
            Task.Run(() => TaskMethod("Task 3"));
            Task.Factory.StartNew(() => TaskMethod("Task 4"));
            //标记为长时间运行任务,则任务不会使用线程池,而在单独的线程中运行。
            Task.Factory.StartNew(() => TaskMethod("Task 5"), TaskCreationOptions.LongRunning);
 
            #region 常规的使用方式
            Console.WriteLine("主线程执行业务处理.");
            //创建任务
            Task task = new Task(() =>
            {
                Console.WriteLine("使用System.Threading.Tasks.Task执行异步操作.");
                for (int i = 0; i < 10; i++)
                {
                    Console.WriteLine(i);
                }
            });
            //启动任务,并安排到当前任务队列线程中执行任务(System.Threading.Tasks.TaskScheduler)
            task.Start();
            Console.WriteLine("主线程执行其他处理");
            task.Wait();
            #endregion
 
            Thread.Sleep(TimeSpan.FromSeconds(1));
            Console.ReadLine();
        }
 
        static void TaskMethod(string name)
        {
            Console.WriteLine("Task {0} is running on a thread id {1}. Is thread pool thread: {2}",
                name, Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread);
        }
    }
}

async/await的实现方式:

using System;
using System.Threading;
using System.Threading.Tasks;
 
namespace ConsoleApp1
{
    class Program
    {
        async static void AsyncFunction()
        {
            await Task.Delay(1);
            Console.WriteLine("使用System.Threading.Tasks.Task执行异步操作.");
            for (int i = 0; i < 10; i++)
            {
                Console.WriteLine(string.Format("AsyncFunction:i={0}", i));
            }
        }
 
        public static void Main()
        {
            Console.WriteLine("主线程执行业务处理.");
            AsyncFunction();
            Console.WriteLine("主线程执行其他处理");
            for (int i = 0; i < 10; i++)
            {
                Console.WriteLine(string.Format("Main:i={0}", i));
            }
            Console.ReadLine();
        }
    }
}

带返回值的方式
　　方式4:
　　Task task = CreateTask("Task 1");
　　task.Start();
　　int result = task.Result;

using System;
using System.Threading;
using System.Threading.Tasks;
 
namespace ConsoleApp1
{
    class Program
    {
        static Task<int> CreateTask(string name)
        {
            return new Task<int>(() => TaskMethod(name));
        }
 
        static void Main(string[] args)
        {
            TaskMethod("Main Thread Task");
            Task<int> task = CreateTask("Task 1");
            task.Start();
            int result = task.Result;
            Console.WriteLine("Task 1 Result is: {0}", result);
 
            task = CreateTask("Task 2");
            //该任务会运行在主线程中
            task.RunSynchronously();
            result = task.Result;
            Console.WriteLine("Task 2 Result is: {0}", result);
 
            task = CreateTask("Task 3");
            Console.WriteLine(task.Status);
            task.Start();
 
            while (!task.IsCompleted)
            {
                Console.WriteLine(task.Status);
                Thread.Sleep(TimeSpan.FromSeconds(0.5));
            }
 
            Console.WriteLine(task.Status);
            result = task.Result;
            Console.WriteLine("Task 3 Result is: {0}", result);
 
            #region 常规使用方式
            //创建任务
            Task<int> getsumtask = new Task<int>(() => Getsum());
            //启动任务,并安排到当前任务队列线程中执行任务(System.Threading.Tasks.TaskScheduler)
            getsumtask.Start();
            Console.WriteLine("主线程执行其他处理");
            //等待任务的完成执行过程。
            getsumtask.Wait();
            //获得任务的执行结果
            Console.WriteLine("任务执行结果：{0}", getsumtask.Result.ToString());
            #endregion
        }
 
        static int TaskMethod(string name)
        {
            Console.WriteLine("Task {0} is running on a thread id {1}. Is thread pool thread: {2}",
                name, Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread);
            Thread.Sleep(TimeSpan.FromSeconds(2));
            return 42;
        }
 
        static int Getsum()
        {
            int sum = 0;
            Console.WriteLine("使用Task执行异步操作.");
            for (int i = 0; i < 100; i++)
            {
                sum += i;
            }
            return sum;
        }
    }
}

async/await的实现:

using System;
using System.Threading.Tasks;
 
namespace ConsoleApp1
{
    class Program
    {
        public static void Main()
        {
            var ret1 = AsyncGetsum();
            Console.WriteLine("主线程执行其他处理");
            for (int i = 1; i <= 3; i++)
                Console.WriteLine("Call Main()");
            int result = ret1.Result;                  //阻塞主线程
            Console.WriteLine("任务执行结果：{0}", result);
        }
 
        async static Task<int> AsyncGetsum()
        {
            await Task.Delay(1);
            int sum = 0;
            Console.WriteLine("使用Task执行异步操作.");
            for (int i = 0; i < 100; i++)
            {
                sum += i;
            }
            return sum;
        }
    }
}

2.2、组合任务.ContinueWith
　　 简单Demo:

using System;
using System.Threading.Tasks;
 
namespace ConsoleApp1
{
    class Program
    {
        public static void Main()
        {
            //创建一个任务
            Task<int> task = new Task<int>(() =>
            {
                int sum = 0;
                Console.WriteLine("使用Task执行异步操作.");
                for (int i = 0; i < 100; i++)
                {
                    sum += i;
                }
                return sum;
            });
            //启动任务,并安排到当前任务队列线程中执行任务(System.Threading.Tasks.TaskScheduler)
            task.Start();
            Console.WriteLine("主线程执行其他处理");
            //任务完成时执行处理。
            Task cwt = task.ContinueWith(t =>
            {
                Console.WriteLine("任务完成后的执行结果：{0}", t.Result.ToString());
            });
            task.Wait();
            cwt.Wait();
        }
    }
}

任务的串行:

using System;
using System.Collections.Concurrent;
using System.Threading;
using System.Threading.Tasks;
 
namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            ConcurrentStack<int> stack = new ConcurrentStack<int>();
 
            //t1先串行
            var t1 = Task.Factory.StartNew(() =>
            {
                stack.Push(1);
                stack.Push(2);
            });
 
            //t2,t3并行执行
            var t2 = t1.ContinueWith(t =>
            {
                int result;
                stack.TryPop(out result);
                Console.WriteLine("Task t2 result={0},Thread id {1}", result, Thread.CurrentThread.ManagedThreadId);
            });
 
            //t2,t3并行执行
            var t3 = t1.ContinueWith(t =>
            {
                int result;
                stack.TryPop(out result);
                Console.WriteLine("Task t3 result={0},Thread id {1}", result, Thread.CurrentThread.ManagedThreadId);
            });
 
            //等待t2和t3执行完
            Task.WaitAll(t2, t3);
 
            //t7串行执行
            var t4 = Task.Factory.StartNew(() =>
            {
                Console.WriteLine("当前集合元素个数：{0},Thread id {1}", stack.Count, Thread.CurrentThread.ManagedThreadId);
            });
            t4.Wait();
        }
    }
}

子任务:

using System;
using System.Threading.Tasks;
 
namespace ConsoleApp1
{
    class Program
    {
        public static void Main()
        {
            Task<string[]> parent = new Task<string[]>(state =>
            {
                Console.WriteLine(state);
                string[] result = new string[2];
                //创建并启动子任务
                new Task(() => { result[0] = "我是子任务1。"; }, TaskCreationOptions.AttachedToParent).Start();
                new Task(() => { result[1] = "我是子任务2。"; }, TaskCreationOptions.AttachedToParent).Start();
                return result;
            }, "我是父任务，并在我的处理过程中创建多个子任务，所有子任务完成以后我才会结束执行。");
            //任务处理完成后执行的操作
            parent.ContinueWith(t =>
            {
                Array.ForEach(t.Result, r => Console.WriteLine(r));
            });
            //启动父任务
            parent.Start();
            //等待任务结束 Wait只能等待父线程结束,没办法等到父线程的ContinueWith结束
            //parent.Wait();
            Console.ReadLine();
 
        }
    }
}

动态并行(TaskCreationOptions.AttachedToParent) 父任务等待所有子任务完成后 整个任务才算完成

using System;
using System.Threading;
using System.Threading.Tasks;
 
namespace ConsoleApp1
{
    class Node
    {
        public Node Left { get; set; }
        public Node Right { get; set; }
        public string Text { get; set; }
    }
 
 
    class Program
    {
        static Node GetNode()
        {
            Node root = new Node
            {
                Left = new Node
                {
                    Left = new Node
                    {
                        Text = "L-L"
                    },
                    Right = new Node
                    {
                        Text = "L-R"
                    },
                    Text = "L"
                },
                Right = new Node
                {
                    Left = new Node
                    {
                        Text = "R-L"
                    },
                    Right = new Node
                    {
                        Text = "R-R"
                    },
                    Text = "R"
                },
                Text = "Root"
            };
            return root;
        }
 
        static void Main(string[] args)
        {
            Node root = GetNode();
            DisplayTree(root);
        }
 
        static void DisplayTree(Node root)
        {
            var task = Task.Factory.StartNew(() => DisplayNode(root),
                                            CancellationToken.None,
                                            TaskCreationOptions.None,
                                            TaskScheduler.Default);
            task.Wait();
        }
 
        static void DisplayNode(Node current)
        {
 
            if (current.Left != null)
                Task.Factory.StartNew(() => DisplayNode(current.Left),
                                            CancellationToken.None,
                                            TaskCreationOptions.AttachedToParent,
                                            TaskScheduler.Default);
            if (current.Right != null)
                Task.Factory.StartNew(() => DisplayNode(current.Right),
                                            CancellationToken.None,
                                            TaskCreationOptions.AttachedToParent,
                                            TaskScheduler.Default);
            Console.WriteLine("当前节点的值为{0};处理的ThreadId={1}", current.Text, Thread.CurrentThread.ManagedThreadId);
        }
    }
}

2.3、取消任务 CancellationTokenSource

using System;
using System.Threading;
using System.Threading.Tasks;
 
namespace ConsoleApp1
{
    class Program
    {
        private static int TaskMethod(string name, int seconds, CancellationToken token)
        {
            Console.WriteLine("Task {0} is running on a thread id {1}. Is thread pool thread: {2}",
                name, Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread);
            for (int i = 0; i < seconds; i++)
            {
                Thread.Sleep(TimeSpan.FromSeconds(1));
                if (token.IsCancellationRequested) return -1;
            }
            return 42 * seconds;
        }
 
        private static void Main(string[] args)
        {
            var cts = new CancellationTokenSource();
            var longTask = new Task<int>(() => TaskMethod("Task 1", 10, cts.Token), cts.Token);
            Console.WriteLine(longTask.Status);
            cts.Cancel();
            Console.WriteLine(longTask.Status);
            Console.WriteLine("First task has been cancelled before execution");
            cts = new CancellationTokenSource();
            longTask = new Task<int>(() => TaskMethod("Task 2", 10, cts.Token), cts.Token);
            longTask.Start();
            for (int i = 0; i < 5; i++)
            {
                Thread.Sleep(TimeSpan.FromSeconds(0.5));
                Console.WriteLine(longTask.Status);
            }
            cts.Cancel();
            for (int i = 0; i < 5; i++)
            {
                Thread.Sleep(TimeSpan.FromSeconds(0.5));
                Console.WriteLine(longTask.Status);
            }
 
            Console.WriteLine("A task has been completed with result {0}.", longTask.Result);
        }
    }
}

2.4、处理任务中的异常
　　单个任务:

using System;
using System.Threading;
using System.Threading.Tasks;
 
namespace ConsoleApp1
{
    class Program
    {
        static int TaskMethod(string name, int seconds)
        {
            Console.WriteLine("Task {0} is running on a thread id {1}. Is thread pool thread: {2}",
                name, Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread);
            Thread.Sleep(TimeSpan.FromSeconds(seconds));
            throw new Exception("Boom!");
            return 42 * seconds;
        }
 
        static void Main(string[] args)
        {
            try
            {
                Task<int> task = Task.Run(() => TaskMethod("Task 2", 2));
                int result = task.GetAwaiter().GetResult();
                Console.WriteLine("Result: {0}", result);
            }
            catch (Exception ex)
            {
                Console.WriteLine("Task 2 Exception caught: {0}", ex.Message);
            }
            Console.WriteLine("----------------------------------------------");
            Console.WriteLine();
        }
    }
}

多个任务:

using System;
using System.Threading;
using System.Threading.Tasks;
 
namespace ConsoleApp1
{
    class Program
    {
        static int TaskMethod(string name, int seconds)
        {
            Console.WriteLine("Task {0} is running on a thread id {1}. Is thread pool thread: {2}",
                name, Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread);
            Thread.Sleep(TimeSpan.FromSeconds(seconds));
            throw new Exception(string.Format("Task {0} Boom!", name));
            return 42 * seconds;
        }
 
 
        public static void Main(string[] args)
        {
            try
            {
                var t1 = new Task<int>(() => TaskMethod("Task 3", 3));
                var t2 = new Task<int>(() => TaskMethod("Task 4", 2));
                var complexTask = Task.WhenAll(t1, t2);
                var exceptionHandler = complexTask.ContinueWith(t =>
                        Console.WriteLine("Result: {0}", t.Result),
                        TaskContinuationOptions.OnlyOnFaulted
                    );
                t1.Start();
                t2.Start();
                Task.WaitAll(t1, t2);
            }
            catch (AggregateException ex)
            {
                ex.Handle(exception =>
                {
                    Console.WriteLine(exception.Message);
                    return true;
                });
            }
        }
    }
}

async/await的方式:

using System;
using System.Threading;
using System.Threading.Tasks;
 
namespace ConsoleApp1
{
    class Program
    {
        static async Task ThrowNotImplementedExceptionAsync()
        {
            throw new NotImplementedException();
        }
 
        static async Task ThrowInvalidOperationExceptionAsync()
        {
            throw new InvalidOperationException();
        }
 
        static async Task Normal()
        {
            await Fun();
        }
 
        static Task Fun()
        {
            return Task.Run(() =>
            {
                for (int i = 1; i <= 10; i++)
                {
                    Console.WriteLine("i={0}", i);
                    Thread.Sleep(200);
                }
            });
        }
 
        static async Task ObserveOneExceptionAsync()
        {
            var task1 = ThrowNotImplementedExceptionAsync();
            var task2 = ThrowInvalidOperationExceptionAsync();
            var task3 = Normal();
 
 
            try
            {
                //异步的方式
                Task allTasks = Task.WhenAll(task1, task2, task3);
                await allTasks;
                //同步的方式
                //Task.WaitAll(task1, task2, task3);
            }
            catch (NotImplementedException ex)
            {
                Console.WriteLine("task1 任务报错!");
            }
            catch (InvalidOperationException ex)
            {
                Console.WriteLine("task2 任务报错!");
            }
            catch (Exception ex)
            {
                Console.WriteLine("任务报错!");
            }
 
        }
 
        public static void Main()
        {
            Task task = ObserveOneExceptionAsync();
            Console.WriteLine("主线程继续运行........");
            task.Wait();
        }
    }
}

2.5、Task.FromResult的应用

using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
 
namespace ConsoleApp1
{
    class Program
    {
        static IDictionary<string, string> cache = new Dictionary<string, string>()
        {
            {"0001","A"},
            {"0002","B"},
            {"0003","C"},
            {"0004","D"},
            {"0005","E"},
            {"0006","F"},
        };
 
        public static void Main()
        {
            Task<string> task = GetValueFromCache("0006");
            Console.WriteLine("主程序继续执行。。。。");
            string result = task.Result;
            Console.WriteLine("result={0}", result);
 
        }
 
        private static Task<string> GetValueFromCache(string key)
        {
            Console.WriteLine("GetValueFromCache开始执行。。。。");
            string result = string.Empty;
            //Task.Delay(5000);
            Thread.Sleep(5000);
            Console.WriteLine("GetValueFromCache继续执行。。。。");
            if (cache.TryGetValue(key, out result))
            {
                return Task.FromResult(result);
            }
            return Task.FromResult("");
        }
 
    }
}

2.6、使用IProgress实现异步编程的进程通知
　　IProgress只提供了一个方法void Report(T value)，通过Report方法把一个T类型的值报告给IProgress,然后IProgress的实现类Progress的构造函数接收类型为Action的形参，通过这个委托让进度显示在UI界面中。

using System;
using System.Threading;
using System.Threading.Tasks;
 
namespace ConsoleApp1
{
    class Program
    {
        static void DoProcessing(IProgress<int> progress)
        {
            for (int i = 0; i <= 100; ++i)
            {
                Thread.Sleep(100);
                if (progress != null)
                {
                    progress.Report(i);
                }
            }
        }
 
        static async Task Display()
        {
            //当前线程
            var progress = new Progress<int>(percent =>
            {
                Console.Clear();
                Console.Write("{0}%", percent);
            });
            //线程池线程
            await Task.Run(() => DoProcessing(progress));
            Console.WriteLine("");
            Console.WriteLine("结束");
        }
 
        public static void Main()
        {
            Task task = Display();
            task.Wait();
        }
    }
}

2.7、Factory.FromAsync的应用 (简APM模式(委托)转换为任务)(BeginXXX和EndXXX)
　　带回调方式的

using System;
using System.Threading;
using System.Threading.Tasks;
 
namespace ConsoleApp1
{
    class Program
    {
        private delegate string AsynchronousTask(string threadName);
 
        private static string Test(string threadName)
        {
            Console.WriteLine("Starting...");
            Console.WriteLine("Is thread pool thread: {0}", Thread.CurrentThread.IsThreadPoolThread);
            Thread.Sleep(TimeSpan.FromSeconds(2));
            Thread.CurrentThread.Name = threadName;
            return string.Format("Thread name: {0}", Thread.CurrentThread.Name);
        }
 
        private static void Callback(IAsyncResult ar)
        {
            Console.WriteLine("Starting a callback...");
            Console.WriteLine("State passed to a callbak: {0}", ar.AsyncState);
            Console.WriteLine("Is thread pool thread: {0}", Thread.CurrentThread.IsThreadPoolThread);
            Console.WriteLine("Thread pool worker thread id: {0}", Thread.CurrentThread.ManagedThreadId);
        }
 
        //执行的流程是 先执行Test--->Callback--->task.ContinueWith
        static void Main(string[] args)
        {
            AsynchronousTask d = Test;
            Console.WriteLine("Option 1");
            Task<string> task = Task<string>.Factory.FromAsync(
                d.BeginInvoke("AsyncTaskThread", Callback, "a delegate asynchronous call"), d.EndInvoke);
 
            task.ContinueWith(t => Console.WriteLine("Callback is finished, now running a continuation! Result: {0}",
                t.Result));
 
            while (!task.IsCompleted)
            {
                Console.WriteLine(task.Status);
                Thread.Sleep(TimeSpan.FromSeconds(0.5));
            }
            Console.WriteLine(task.Status);
 
        }
    }
}

不带回调方式的:

using System;
using System.Threading;
using System.Threading.Tasks;
 
namespace ConsoleApp1
{
    class Program
    {
        private delegate string AsynchronousTask(string threadName);
 
        private static string Test(string threadName)
        {
            Console.WriteLine("Starting...");
            Console.WriteLine("Is thread pool thread: {0}", Thread.CurrentThread.IsThreadPoolThread);
            Thread.Sleep(TimeSpan.FromSeconds(2));
            Thread.CurrentThread.Name = threadName;
            return string.Format("Thread name: {0}", Thread.CurrentThread.Name);
        }
 
        //执行的流程是 先执行Test--->task.ContinueWith
        static void Main(string[] args)
        {
            AsynchronousTask d = Test;
            Task<string> task = Task<string>.Factory.FromAsync(
                d.BeginInvoke, d.EndInvoke, "AsyncTaskThread", "a delegate asynchronous call");
            task.ContinueWith(t => Console.WriteLine("Task is completed, now running a continuation! Result: {0}",
                t.Result));
            while (!task.IsCompleted)
            {
                Console.WriteLine(task.Status);
                Thread.Sleep(TimeSpan.FromSeconds(0.5));
            }
            Console.WriteLine(task.Status);
 
        }
    }
}

1、Task的优势
　　ThreadPool相比Thread来说具备了很多优势，但是ThreadPool却又存在一些使用上的不方便。比如：
　　◆ ThreadPool不支持线程的取消、完成、失败通知等交互性操作；
　　◆ ThreadPool不支持线程执行的先后次序；
　　以往，如果开发者要实现上述功能，需要完成很多额外的工作，现在，FCL中提供了一个功能更强大的概念：Task。Task在线程池的基础上进行了优化，并提供了更多的API。在FCL4.0中，如果我们要编写多线程程序，Task显然已经优于传统的方式。
　　以下是一个简单的任务示例：

  1. using System;
  2. using System.Threading;
  3. using System.Threading.Tasks;
  4.  
  5. namespace ConsoleApp1
  6. {
  7. class Program
  8. {
  9. static void Main(string[] args)
  10. {
  11. Task t = new Task(() =>
  12. {
  13. Console.WriteLine("任务开始工作……");
  14. //模拟工作过程
  15. Thread.Sleep(5000);
  16. });
  17. t.Start();
  18. t.ContinueWith((task) =>
  19. {
  20. Console.WriteLine("任务完成，完成时候的状态为：");
  21. Console.WriteLine("IsCanceled={0}\tIsCompleted={1}\tIsFaulted={2}", task.IsCanceled, task.IsCompleted, task.IsFaulted);
  22. });
  23. Console.ReadKey();
  24. }
  25. }
  26. }

2、Task的用法
　　2.1、创建任务
　　无返回值的方式
　　方式1:
　　var t1 = new Task(() => TaskMethod("Task 1"));
　　t1.Start();
　　Task.WaitAll(t1);//等待所有任务结束
　　注:
　　任务的状态:
　　Start之前为:Created
　　Start之后为:WaitingToRun

　　方式2:
　　Task.Run(() => TaskMethod("Task 2"));

　　方式3:
　　Task.Factory.StartNew(() => TaskMethod("Task 3")); 直接异步的方法
　　或者
　　var t3=Task.Factory.StartNew(() => TaskMethod("Task 3"));
　　Task.WaitAll(t3);//等待所有任务结束
　　注:
　　任务的状态:
　　Start之前为:Running
　　Start之后为:Running

  1. using System;
  2. using System.Threading;
  3. using System.Threading.Tasks;
  4.  
  5. namespace ConsoleApp1
  6. {
  7. class Program
  8. {
  9. static void Main(string[] args)
  10. {
  11. var t1 = new Task(() => TaskMethod("Task 1"));
  12. var t2 = new Task(() => TaskMethod("Task 2"));
  13. t2.Start();
  14. t1.Start();
  15. Task.WaitAll(t1, t2);
  16. Task.Run(() => TaskMethod("Task 3"));
  17. Task.Factory.StartNew(() => TaskMethod("Task 4"));
  18. //标记为长时间运行任务,则任务不会使用线程池,而在单独的线程中运行。
  19. Task.Factory.StartNew(() => TaskMethod("Task 5"), TaskCreationOptions.LongRunning);
  20.  
  21. #region 常规的使用方式
  22. Console.WriteLine("主线程执行业务处理.");
  23. //创建任务
  24. Task task = new Task(() =>
  25. {
  26. Console.WriteLine("使用System.Threading.Tasks.Task执行异步操作.");
  27. for (int i = 0; i < 10; i++)
  28. {
  29. Console.WriteLine(i);
  30. }
  31. });
  32. //启动任务,并安排到当前任务队列线程中执行任务(System.Threading.Tasks.TaskScheduler)
  33. task.Start();
  34. Console.WriteLine("主线程执行其他处理");
  35. task.Wait();
  36. #endregion
  37.  
  38. Thread.Sleep(TimeSpan.FromSeconds(1));
  39. Console.ReadLine();
  40. }
  41.  
  42. static void TaskMethod(string name)
  43. {
  44. Console.WriteLine("Task {0} is running on a thread id {1}. Is thread pool thread: {2}",
  45. name, Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread);
  46. }
  47. }
  48. }

async/await的实现方式:

  1. using System;
  2. using System.Threading;
  3. using System.Threading.Tasks;
  4.  
  5. namespace ConsoleApp1
  6. {
  7. class Program
  8. {
  9. async static void AsyncFunction()
  10. {
  11. await Task.Delay(1);
  12. Console.WriteLine("使用System.Threading.Tasks.Task执行异步操作.");
  13. for (int i = 0; i < 10; i++)
  14. {
  15. Console.WriteLine(string.Format("AsyncFunction:i={0}", i));
  16. }
  17. }
  18.  
  19. public static void Main()
  20. {
  21. Console.WriteLine("主线程执行业务处理.");
  22. AsyncFunction();
  23. Console.WriteLine("主线程执行其他处理");
  24. for (int i = 0; i < 10; i++)
  25. {
  26. Console.WriteLine(string.Format("Main:i={0}", i));
  27. }
  28. Console.ReadLine();
  29. }
  30. }
  31. }

带返回值的方式
　　方式4:
　　Task task = CreateTask("Task 1");
　　task.Start();
　　int result = task.Result;

  1. using System;
  2. using System.Threading;
  3. using System.Threading.Tasks;
  4.  
  5. namespace ConsoleApp1
  6. {
  7. class Program
  8. {
  9. static Task<int> CreateTask(string name)
  10. {
  11. return new Task<int>(() => TaskMethod(name));
  12. }
  13.  
  14. static void Main(string[] args)
  15. {
  16. TaskMethod("Main Thread Task");
  17. Task<int> task = CreateTask("Task 1");
  18. task.Start();
  19. int result = task.Result;
  20. Console.WriteLine("Task 1 Result is: {0}", result);
  21.  
  22. task = CreateTask("Task 2");
  23. //该任务会运行在主线程中
  24. task.RunSynchronously();
  25. result = task.Result;
  26. Console.WriteLine("Task 2 Result is: {0}", result);
  27.  
  28. task = CreateTask("Task 3");
  29. Console.WriteLine(task.Status);
  30. task.Start();
  31.  
  32. while (!task.IsCompleted)
  33. {
  34. Console.WriteLine(task.Status);
  35. Thread.Sleep(TimeSpan.FromSeconds(0.5));
  36. }
  37.  
  38. Console.WriteLine(task.Status);
  39. result = task.Result;
  40. Console.WriteLine("Task 3 Result is: {0}", result);
  41.  
  42. #region 常规使用方式
  43. //创建任务
  44. Task<int> getsumtask = new Task<int>(() => Getsum());
  45. //启动任务,并安排到当前任务队列线程中执行任务(System.Threading.Tasks.TaskScheduler)
  46. getsumtask.Start();
  47. Console.WriteLine("主线程执行其他处理");
  48. //等待任务的完成执行过程。
  49. getsumtask.Wait();
  50. //获得任务的执行结果
  51. Console.WriteLine("任务执行结果：{0}", getsumtask.Result.ToString());
  52. #endregion
  53. }
  54.  
  55. static int TaskMethod(string name)
  56. {
  57. Console.WriteLine("Task {0} is running on a thread id {1}. Is thread pool thread: {2}",
  58. name, Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread);
  59. Thread.Sleep(TimeSpan.FromSeconds(2));
  60. return 42;
  61. }
  62.  
  63. static int Getsum()
  64. {
  65. int sum = 0;
  66. Console.WriteLine("使用Task执行异步操作.");
  67. for (int i = 0; i < 100; i++)
  68. {
  69. sum += i;
  70. }
  71. return sum;
  72. }
  73. }
  74. }

async/await的实现:

  1. using System;
  2. using System.Threading.Tasks;
  3.  
  4. namespace ConsoleApp1
  5. {
  6. class Program
  7. {
  8. public static void Main()
  9. {
  10. var ret1 = AsyncGetsum();
  11. Console.WriteLine("主线程执行其他处理");
  12. for (int i = 1; i <= 3; i++)
  13. Console.WriteLine("Call Main()");
  14. int result = ret1.Result; //阻塞主线程
  15. Console.WriteLine("任务执行结果：{0}", result);
  16. }
  17.  
  18. async static Task<int> AsyncGetsum()
  19. {
  20. await Task.Delay(1);
  21. int sum = 0;
  22. Console.WriteLine("使用Task执行异步操作.");
  23. for (int i = 0; i < 100; i++)
  24. {
  25. sum += i;
  26. }
  27. return sum;
  28. }
  29. }
  30. }

2.2、组合任务.ContinueWith
　　 简单Demo:

  1. using System;
  2. using System.Threading.Tasks;
  3.  
  4. namespace ConsoleApp1
  5. {
  6. class Program
  7. {
  8. public static void Main()
  9. {
  10. //创建一个任务
  11. Task<int> task = new Task<int>(() =>
  12. {
  13. int sum = 0;
  14. Console.WriteLine("使用Task执行异步操作.");
  15. for (int i = 0; i < 100; i++)
  16. {
  17. sum += i;
  18. }
  19. return sum;
  20. });
  21. //启动任务,并安排到当前任务队列线程中执行任务(System.Threading.Tasks.TaskScheduler)
  22. task.Start();
  23. Console.WriteLine("主线程执行其他处理");
  24. //任务完成时执行处理。
  25. Task cwt = task.ContinueWith(t =>
  26. {
  27. Console.WriteLine("任务完成后的执行结果：{0}", t.Result.ToString());
  28. });
  29. task.Wait();
  30. cwt.Wait();
  31. }
  32. }
  33. }

任务的串行:

  1. using System;
  2. using System.Collections.Concurrent;
  3. using System.Threading;
  4. using System.Threading.Tasks;
  5.  
  6. namespace ConsoleApp1
  7. {
  8. class Program
  9. {
  10. static void Main(string[] args)
  11. {
  12. ConcurrentStack<int> stack = new ConcurrentStack<int>();
  13.  
  14. //t1先串行
  15. var t1 = Task.Factory.StartNew(() =>
  16. {
  17. stack.Push(1);
  18. stack.Push(2);
  19. });
  20.  
  21. //t2,t3并行执行
  22. var t2 = t1.ContinueWith(t =>
  23. {
  24. int result;
  25. stack.TryPop(out result);
  26. Console.WriteLine("Task t2 result={0},Thread id {1}", result, Thread.CurrentThread.ManagedThreadId);
  27. });
  28.  
  29. //t2,t3并行执行
  30. var t3 = t1.ContinueWith(t =>
  31. {
  32. int result;
  33. stack.TryPop(out result);
  34. Console.WriteLine("Task t3 result={0},Thread id {1}", result, Thread.CurrentThread.ManagedThreadId);
  35. });
  36.  
  37. //等待t2和t3执行完
  38. Task.WaitAll(t2, t3);
  39.  
  40. //t7串行执行
  41. var t4 = Task.Factory.StartNew(() =>
  42. {
  43. Console.WriteLine("当前集合元素个数：{0},Thread id {1}", stack.Count, Thread.CurrentThread.ManagedThreadId);
  44. });
  45. t4.Wait();
  46. }
  47. }
  48. }

子任务:

  1. using System;
  2. using System.Threading.Tasks;
  3.  
  4. namespace ConsoleApp1
  5. {
  6. class Program
  7. {
  8. public static void Main()
  9. {
  10. Task<string[]> parent = new Task<string[]>(state =>
  11. {
  12. Console.WriteLine(state);
  13. string[] result = new string[2];
  14. //创建并启动子任务
  15. new Task(() => { result[0] = "我是子任务1。"; }, TaskCreationOptions.AttachedToParent).Start();
  16. new Task(() => { result[1] = "我是子任务2。"; }, TaskCreationOptions.AttachedToParent).Start();
  17. return result;
  18. }, "我是父任务，并在我的处理过程中创建多个子任务，所有子任务完成以后我才会结束执行。");
  19. //任务处理完成后执行的操作
  20. parent.ContinueWith(t =>
  21. {
  22. Array.ForEach(t.Result, r => Console.WriteLine(r));
  23. });
  24. //启动父任务
  25. parent.Start();
  26. //等待任务结束 Wait只能等待父线程结束,没办法等到父线程的ContinueWith结束
  27. //parent.Wait();
  28. Console.ReadLine();
  29.  
  30. }
  31. }
  32. }

动态并行(TaskCreationOptions.AttachedToParent) 父任务等待所有子任务完成后 整个任务才算完成

  1. using System;
  2. using System.Threading;
  3. using System.Threading.Tasks;
  4.  
  5. namespace ConsoleApp1
  6. {
  7. class Node
  8. {
  9. public Node Left { get; set; }
  10. public Node Right { get; set; }
  11. public string Text { get; set; }
  12. }
  13.  
  14.  
  15. class Program
  16. {
  17. static Node GetNode()
  18. {
  19. Node root = new Node
  20. {
  21. Left = new Node
  22. {
  23. Left = new Node
  24. {
  25. Text = "L-L"
  26. },
  27. Right = new Node
  28. {
  29. Text = "L-R"
  30. },
  31. Text = "L"
  32. },
  33. Right = new Node
  34. {
  35. Left = new Node
  36. {
  37. Text = "R-L"
  38. },
  39. Right = new Node
  40. {
  41. Text = "R-R"
  42. },
  43. Text = "R"
  44. },
  45. Text = "Root"
  46. };
  47. return root;
  48. }
  49.  
  50. static void Main(string[] args)
  51. {
  52. Node root = GetNode();
  53. DisplayTree(root);
  54. }
  55.  
  56. static void DisplayTree(Node root)
  57. {
  58. var task = Task.Factory.StartNew(() => DisplayNode(root),
  59. CancellationToken.None,
  60. TaskCreationOptions.None,
  61. TaskScheduler.Default);
  62. task.Wait();
  63. }
  64.  
  65. static void DisplayNode(Node current)
  66. {
  67.  
  68. if (current.Left != null)
  69. Task.Factory.StartNew(() => DisplayNode(current.Left),
  70. CancellationToken.None,
  71. TaskCreationOptions.AttachedToParent,
  72. TaskScheduler.Default);
  73. if (current.Right != null)
  74. Task.Factory.StartNew(() => DisplayNode(current.Right),
  75. CancellationToken.None,
  76. TaskCreationOptions.AttachedToParent,
  77. TaskScheduler.Default);
  78. Console.WriteLine("当前节点的值为{0};处理的ThreadId={1}", current.Text, Thread.CurrentThread.ManagedThreadId);
  79. }
  80. }
  81. }

2.3、取消任务 CancellationTokenSource

  1. using System;
  2. using System.Threading;
  3. using System.Threading.Tasks;
  4.  
  5. namespace ConsoleApp1
  6. {
  7. class Program
  8. {
  9. private static int TaskMethod(string name, int seconds, CancellationToken token)
  10. {
  11. Console.WriteLine("Task {0} is running on a thread id {1}. Is thread pool thread: {2}",
  12. name, Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread);
  13. for (int i = 0; i < seconds; i++)
  14. {
  15. Thread.Sleep(TimeSpan.FromSeconds(1));
  16. if (token.IsCancellationRequested) return -1;
  17. }
  18. return 42 * seconds;
  19. }
  20.  
  21. private static void Main(string[] args)
  22. {
  23. var cts = new CancellationTokenSource();
  24. var longTask = new Task<int>(() => TaskMethod("Task 1", 10, cts.Token), cts.Token);
  25. Console.WriteLine(longTask.Status);
  26. cts.Cancel();
  27. Console.WriteLine(longTask.Status);
  28. Console.WriteLine("First task has been cancelled before execution");
  29. cts = new CancellationTokenSource();
  30. longTask = new Task<int>(() => TaskMethod("Task 2", 10, cts.Token), cts.Token);
  31. longTask.Start();
  32. for (int i = 0; i < 5; i++)
  33. {
  34. Thread.Sleep(TimeSpan.FromSeconds(0.5));
  35. Console.WriteLine(longTask.Status);
  36. }
  37. cts.Cancel();
  38. for (int i = 0; i < 5; i++)
  39. {
  40. Thread.Sleep(TimeSpan.FromSeconds(0.5));
  41. Console.WriteLine(longTask.Status);
  42. }
  43.  
  44. Console.WriteLine("A task has been completed with result {0}.", longTask.Result);
  45. }
  46. }
  47. }

2.4、处理任务中的异常
　　单个任务:

  1. using System;
  2. using System.Threading;
  3. using System.Threading.Tasks;
  4.  
  5. namespace ConsoleApp1
  6. {
  7. class Program
  8. {
  9. static int TaskMethod(string name, int seconds)
  10. {
  11. Console.WriteLine("Task {0} is running on a thread id {1}. Is thread pool thread: {2}",
  12. name, Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread);
  13. Thread.Sleep(TimeSpan.FromSeconds(seconds));
  14. throw new Exception("Boom!");
  15. return 42 * seconds;
  16. }
  17.  
  18. static void Main(string[] args)
  19. {
  20. try
  21. {
  22. Task<int> task = Task.Run(() => TaskMethod("Task 2", 2));
  23. int result = task.GetAwaiter().GetResult();
  24. Console.WriteLine("Result: {0}", result);
  25. }
  26. catch (Exception ex)
  27. {
  28. Console.WriteLine("Task 2 Exception caught: {0}", ex.Message);
  29. }
  30. Console.WriteLine("----------------------------------------------");
  31. Console.WriteLine();
  32. }
  33. }
  34. }

多个任务:

  1. using System;
  2. using System.Threading;
  3. using System.Threading.Tasks;
  4.  
  5. namespace ConsoleApp1
  6. {
  7. class Program
  8. {
  9. static int TaskMethod(string name, int seconds)
  10. {
  11. Console.WriteLine("Task {0} is running on a thread id {1}. Is thread pool thread: {2}",
  12. name, Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread);
  13. Thread.Sleep(TimeSpan.FromSeconds(seconds));
  14. throw new Exception(string.Format("Task {0} Boom!", name));
  15. return 42 * seconds;
  16. }
  17.  
  18.  
  19. public static void Main(string[] args)
  20. {
  21. try
  22. {
  23. var t1 = new Task<int>(() => TaskMethod("Task 3", 3));
  24. var t2 = new Task<int>(() => TaskMethod("Task 4", 2));
  25. var complexTask = Task.WhenAll(t1, t2);
  26. var exceptionHandler = complexTask.ContinueWith(t =>
  27. Console.WriteLine("Result: {0}", t.Result),
  28. TaskContinuationOptions.OnlyOnFaulted
  29. );
  30. t1.Start();
  31. t2.Start();
  32. Task.WaitAll(t1, t2);
  33. }
  34. catch (AggregateException ex)
  35. {
  36. ex.Handle(exception =>
  37. {
  38. Console.WriteLine(exception.Message);
  39. return true;
  40. });
  41. }
  42. }
  43. }
  44. }

async/await的方式:

  1. using System;
  2. using System.Threading;
  3. using System.Threading.Tasks;
  4.  
  5. namespace ConsoleApp1
  6. {
  7. class Program
  8. {
  9. static async Task ThrowNotImplementedExceptionAsync()
  10. {
  11. throw new NotImplementedException();
  12. }
  13.  
  14. static async Task ThrowInvalidOperationExceptionAsync()
  15. {
  16. throw new InvalidOperationException();
  17. }
  18.  
  19. static async Task Normal()
  20. {
  21. await Fun();
  22. }
  23.  
  24. static Task Fun()
  25. {
  26. return Task.Run(() =>
  27. {
  28. for (int i = 1; i <= 10; i++)
  29. {
  30. Console.WriteLine("i={0}", i);
  31. Thread.Sleep(200);
  32. }
  33. });
  34. }
  35.  
  36. static async Task ObserveOneExceptionAsync()
  37. {
  38. var task1 = ThrowNotImplementedExceptionAsync();
  39. var task2 = ThrowInvalidOperationExceptionAsync();
  40. var task3 = Normal();
  41.  
  42.  
  43. try
  44. {
  45. //异步的方式
  46. Task allTasks = Task.WhenAll(task1, task2, task3);
  47. await allTasks;
  48. //同步的方式
  49. //Task.WaitAll(task1, task2, task3);
  50. }
  51. catch (NotImplementedException ex)
  52. {
  53. Console.WriteLine("task1 任务报错!");
  54. }
  55. catch (InvalidOperationException ex)
  56. {
  57. Console.WriteLine("task2 任务报错!");
  58. }
  59. catch (Exception ex)
  60. {
  61. Console.WriteLine("任务报错!");
  62. }
  63.  
  64. }
  65.  
  66. public static void Main()
  67. {
  68. Task task = ObserveOneExceptionAsync();
  69. Console.WriteLine("主线程继续运行........");
  70. task.Wait();
  71. }
  72. }
  73. }

2.5、Task.FromResult的应用

  1. using System;
  2. using System.Collections.Generic;
  3. using System.Threading;
  4. using System.Threading.Tasks;
  5.  
  6. namespace ConsoleApp1
  7. {
  8. class Program
  9. {
  10. static IDictionary<string, string> cache = new Dictionary<string, string>()
  11. {
  12. {"0001","A"},
  13. {"0002","B"},
  14. {"0003","C"},
  15. {"0004","D"},
  16. {"0005","E"},
  17. {"0006","F"},
  18. };
  19.  
  20. public static void Main()
  21. {
  22. Task<string> task = GetValueFromCache("0006");
  23. Console.WriteLine("主程序继续执行。。。。");
  24. string result = task.Result;
  25. Console.WriteLine("result={0}", result);
  26.  
  27. }
  28.  
  29. private static Task<string> GetValueFromCache(string key)
  30. {
  31. Console.WriteLine("GetValueFromCache开始执行。。。。");
  32. string result = string.Empty;
  33. //Task.Delay(5000);
  34. Thread.Sleep(5000);
  35. Console.WriteLine("GetValueFromCache继续执行。。。。");
  36. if (cache.TryGetValue(key, out result))
  37. {
  38. return Task.FromResult(result);
  39. }
  40. return Task.FromResult("");
  41. }
  42.  
  43. }
  44. }

2.6、使用IProgress实现异步编程的进程通知
　　IProgress只提供了一个方法void Report(T value)，通过Report方法把一个T类型的值报告给IProgress,然后IProgress的实现类Progress的构造函数接收类型为Action的形参，通过这个委托让进度显示在UI界面中。

  1. using System;
  2. using System.Threading;
  3. using System.Threading.Tasks;
  4.  
  5. namespace ConsoleApp1
  6. {
  7. class Program
  8. {
  9. static void DoProcessing(IProgress<int> progress)
  10. {
  11. for (int i = 0; i <= 100; ++i)
  12. {
  13. Thread.Sleep(100);
  14. if (progress != null)
  15. {
  16. progress.Report(i);
  17. }
  18. }
  19. }
  20.  
  21. static async Task Display()
  22. {
  23. //当前线程
  24. var progress = new Progress<int>(percent =>
  25. {
  26. Console.Clear();
  27. Console.Write("{0}%", percent);
  28. });
  29. //线程池线程
  30. await Task.Run(() => DoProcessing(progress));
  31. Console.WriteLine("");
  32. Console.WriteLine("结束");
  33. }
  34.  
  35. public static void Main()
  36. {
  37. Task task = Display();
  38. task.Wait();
  39. }
  40. }
  41. }

2.7、Factory.FromAsync的应用 (简APM模式(委托)转换为任务)(BeginXXX和EndXXX)
　　带回调方式的

  1. using System;
  2. using System.Threading;
  3. using System.Threading.Tasks;
  4.  
  5. namespace ConsoleApp1
  6. {
  7. class Program
  8. {
  9. private delegate string AsynchronousTask(string threadName);
  10.  
  11. private static string Test(string threadName)
  12. {
  13. Console.WriteLine("Starting...");
  14. Console.WriteLine("Is thread pool thread: {0}", Thread.CurrentThread.IsThreadPoolThread);
  15. Thread.Sleep(TimeSpan.FromSeconds(2));
  16. Thread.CurrentThread.Name = threadName;
  17. return string.Format("Thread name: {0}", Thread.CurrentThread.Name);
  18. }
  19.  
  20. private static void Callback(IAsyncResult ar)
  21. {
  22. Console.WriteLine("Starting a callback...");
  23. Console.WriteLine("State passed to a callbak: {0}", ar.AsyncState);
  24. Console.WriteLine("Is thread pool thread: {0}", Thread.CurrentThread.IsThreadPoolThread);
  25. Console.WriteLine("Thread pool worker thread id: {0}", Thread.CurrentThread.ManagedThreadId);
  26. }
  27.  
  28. //执行的流程是 先执行Test--->Callback--->task.ContinueWith
  29. static void Main(string[] args)
  30. {
  31. AsynchronousTask d = Test;
  32. Console.WriteLine("Option 1");
  33. Task<string> task = Task<string>.Factory.FromAsync(
  34. d.BeginInvoke("AsyncTaskThread", Callback, "a delegate asynchronous call"), d.EndInvoke);
  35.  
  36. task.ContinueWith(t => Console.WriteLine("Callback is finished, now running a continuation! Result: {0}",
  37. t.Result));
  38.  
  39. while (!task.IsCompleted)
  40. {
  41. Console.WriteLine(task.Status);
  42. Thread.Sleep(TimeSpan.FromSeconds(0.5));
  43. }
  44. Console.WriteLine(task.Status);
  45.  
  46. }
  47. }
  48. }

不带回调方式的

  1. using System;
  2. using System.Threading;
  3. using System.Threading.Tasks;
  4.  
  5. namespace ConsoleApp1
  6. {
  7. class Program
  8. {
  9. private delegate string AsynchronousTask(string threadName);
  10.  
  11. private static string Test(string threadName)
  12. {
  13. Console.WriteLine("Starting...");
  14. Console.WriteLine("Is thread pool thread: {0}", Thread.CurrentThread.IsThreadPoolThread);
  15. Thread.Sleep(TimeSpan.FromSeconds(2));
  16. Thread.CurrentThread.Name = threadName;
  17. return string.Format("Thread name: {0}", Thread.CurrentThread.Name);
  18. }
  19.  
  20. //执行的流程是 先执行Test--->task.ContinueWith
  21. static void Main(string[] args)
  22. {
  23. AsynchronousTask d = Test;
  24. Task<string> task = Task<string>.Factory.FromAsync(
  25. d.BeginInvoke, d.EndInvoke, "AsyncTaskThread", "a delegate asynchronous call");
  26. task.ContinueWith(t => Console.WriteLine("Task is completed, now running a continuation! Result: {0}",
  27. t.Result));
  28. while (!task.IsCompleted)
  29. {
  30. Console.WriteLine(task.Status);
  31. Thread.Sleep(TimeSpan.FromSeconds(0.5));
  32. }
  33. Console.WriteLine(task.Status);
  34.  
  35. }
  36. }
  37. }
异步TaskC

相关

C# 十六进制八进制前缀或后缀

C#中的Attribute（特性）的使用

scala future 动态并行异步 ;promise jobs join item scala dynamic

c#小灶——9.算术运算符

c#小灶——4.注释和代码规范

c#小灶——3.输出语句

【Luogu3414】SAC#1 - 组合数

[C#] 使用递归将多条路径生成树

C#封装定时执行任务类

【C#进阶系列】30 学习总结

【C#进阶系列】10 属性

【C#进阶系列】18 特性Attribute

标签