Task/Parallel实现异步多线程，等待所有线程结束，Task.WaitAny/Task.WaitAll/Parallel.Invoke阻塞主线程，taskFactory.ContinueWhenAll/taskFactory.ContinueWhenAny非阻塞主线程

代码：cancellationTokenSource.Token.ThrowIfCancellationRequested();

#region Task 异步多线程，Task是基于ThreadPool实现的
            {
                //TestClass testClass = new TestClass();
                //Action<object> action = new Action<object>(t => testClass.TestThread(t.ToString()));

                //TaskFactory taskFactory = new TaskFactory();
                //List<Task> taskList = new List<Task>();
                //for (int i = 0; i < 5; i++)
                //{
                //    Task task = taskFactory.StartNew(action, "task" + i);
                //    taskList.Add(task);
                //}

                //同步等待
                ////1.1所在线程等待，目前在主线程，等待某一个Task执行完毕，只要有一个完成，就继续往下执行。会卡住主线程。
                //Task.WaitAny(taskList.ToArray());
                //Console.WriteLine("某一个Task执行完毕");

                ////1.2所在线程等待，目前在主线程，直到所有Task执行完毕；会卡住主线程。
                //Task.WaitAll(taskList.ToArray());
                //Console.WriteLine("所有Task执行完毕");

                ////2.1回调等待
                ////不卡主线程，所有Task完成，才执行下面的操作
                //taskFactory.ContinueWhenAll(taskList.ToArray(), taskArray =>
                //{
                //    Console.WriteLine("taskFactory.ContinueWhenAll {0}", Thread.CurrentThread.ManagedThreadId);
                //    foreach (var item in taskArray)
                //    {
                //        Console.WriteLine(item.AsyncState);
                //        Console.WriteLine(item.IsCompleted);
                //    }
                //});

                ////2.2回调等待
                ////不卡主线程，有一个Task完成，就执行下面的操作
                //taskFactory.ContinueWhenAny(taskList.ToArray(), taskAction =>
                //{
                //    Console.WriteLine("taskFactory.ContinueWhenAny {0}", Thread.CurrentThread.ManagedThreadId);
                //    Console.WriteLine(taskAction.AsyncState);
                //    Console.WriteLine(taskAction.IsCompleted);
                //});
            }
            #endregion

            #region Parallel 基于Task实现，多个任务并行计算，主线程也会计算，其实就是Task+WaitAll，一定会卡住主线程
            {
                //Console.WriteLine("主线程的ID：{0}", Thread.CurrentThread.ManagedThreadId);
                //Parallel.Invoke(() => { Console.WriteLine("当前线程的ID：{0}", Thread.CurrentThread.ManagedThreadId); },
                //    () => { Console.WriteLine("当前线程的ID：{0}", Thread.CurrentThread.ManagedThreadId); },
                //    () => { Console.WriteLine("当前线程的ID：{0}", Thread.CurrentThread.ManagedThreadId); },
                //    () => { Console.WriteLine("当前线程的ID：{0}", Thread.CurrentThread.ManagedThreadId); },
                //    () => { Console.WriteLine("当前线程的ID：{0}", Thread.CurrentThread.ManagedThreadId); });
                ////全部完成后，进入下一步，看上去就像同步编程

                //Parallel.ForEach<int>(new int[] { 1, 2, 3, 4, 5 }, t =>
                //{
                //    Console.WriteLine("当前线程ID：{0}，结果：{1}", Thread.CurrentThread.ManagedThreadId, t * t);
                //    Thread.Sleep(100);
                //});

                //
                ParallelOptions options = new ParallelOptions()
                {
                    MaxDegreeOfParallelism = 5
                };
                Parallel.For(0, 1000, options, t => { Console.WriteLine("结果：" + t.ToString()); });
                Parallel.For(0, 1000, options, (t, state) => {
                    Console.WriteLine("结果：" + t.ToString());
                    //state.Break();//
                    //state.Stop();//
                    //return;
                });
            }
            #endregion

Foreach

ParallelOptions options = new ParallelOptions()
{
  MaxDegreeOfParallelism = 5
};

var source2 = Enumerable.Range(1, 100);
Parallel.ForEach<int>(source2, options, t =>
{
Thread.Sleep(1000);
Console.WriteLine("ThreadId:" + Thread.CurrentThread.ManagedThreadId + ",结果：" + t.ToString());
});

线程取消

// 定义CancellationTokenSource 控制取消
            CancellationTokenSource _cts = new CancellationTokenSource();
            ParallelOptions parallelOptions = new ParallelOptions()
            {
                MaxDegreeOfParallelism = 5, // 最大并行数
                CancellationToken = _cts.Token//是否取消线程的标记
            };
            // 有重载，parallelOptions 可不传，不传默认是跑满CPU线程：核心数 乘以 2
            // 全部完成后，进入下一步，看上去就像同步编程。
            Parallel.Invoke(
                parallelOptions,
                () =>
                {
                    Thread.Sleep(5000);
                    if (_cts.IsCancellationRequested)
                    {
                        Console.WriteLine("5000已经被取消。");
                        return;
                    }
                    Console.WriteLine("5000当前线程的ID：{0}", Thread.CurrentThread.ManagedThreadId);
                },
                () =>
                {
                    Thread.Sleep(500);
                    if (_cts.IsCancellationRequested)
                    {
                        Console.WriteLine("500已经被取消。");
                        return;
                    }
                    Console.WriteLine("500当前线程的ID：{0}", Thread.CurrentThread.ManagedThreadId);
                },
                () =>
                {
                    Console.WriteLine("进入取消任务，线程ID ： {0}", Thread.CurrentThread.ManagedThreadId);
                    Thread.Sleep(2000);
                    _cts.Cancel();
                    Console.WriteLine("发起取消请求...........");
                }
                );