<Pagex:Class="XamlDemo.Thread.Tasks.TaskDemo"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:local="using:XamlDemo.Thread.Tasks"xmlns:d="http://schemas.microsoft.com/expression/blend/2008"xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"mc:Ignorable="d"><Grid Background="Transparent"><StackPanel Margin="120 0 0 0"><TextBlock Name="lblMsg" FontSize="14.667" /><Button Name="btnCreateTask" Content="执行一个没有返回值的任务" Click="btnCreateTask_Click_1" Margin="0 10 0 0" /><Button Name="btnCancelTask" Content="取消“执行一个没有返回值的任务”" Click="btnCancelTask_Click_1" Margin="0 10 0 0" /><Button Name="btnCreateTaskWithReturn" Content="执行一个带返回值的任务" Click="btnCreateTaskWithReturn_Click_1" Margin="0 30 0 0" /><Button Name="btnCancelTaskWithReturn" Content="取消“执行一个带返回值的任务”" Click="btnCancelTaskWithReturn_Click_1" Margin="0 10 0 0" /></StackPanel></Grid>
</Page>

/** Task - 基于线程池的任务（在 System.Threading.Tasks 命名空间下）*/using System;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using System.Threading.Tasks;
using System.Threading;
using Windows.UI.Core;namespace XamlDemo.Thread.Tasks
{public sealed partial class TaskDemo : Page{/** CancellationTokenSource - 用于取消 CancellationToken *     Token - 一个 CancellationToken 类型的对象，用于关联 Task*     IsCancellationRequested - 是否收到了取消操作的请求*     Cancel() - 发出取消操作的请求*     * CancellationToken - 用于关联 Task，以便取消 Task*     IsCancellationRequested - 是否收到了取消操作的请求*     WaitHandle - 信号，可以通过 WaitHandle.WaitOne() 在当前线程等待*     ThrowIfCancellationRequested() - 如果收到了取消操作的请求，则抛出一个 OperationCanceledException 异常*/private CancellationTokenSource _cts;public TaskDemo(){this.InitializeComponent();}private void btnCreateTask_Click_1(object sender, RoutedEventArgs e){_cts = new CancellationTokenSource();// 实例化一个 Task，可随时通过 task.Status 获取任务状态Task task = new Task((ctx) => // 任务所调用的方法，没有返回值{// 在当前线程上阻塞 3000 毫秒（当收到取消请求时会发出信号，停止阻塞）_cts.Token.WaitHandle.WaitOne(3000);// 收到取消操作的请求后抛出一个 OperationCanceledException 异常，其会导致 task.IsCanceled 的值变为 true// 此处的代码等同于 _cts.Token.ThrowIfCancellationRequested();if (_cts.IsCancellationRequested)throw new OperationCanceledException(_cts.Token);},null, // 上下文对象，task.AsyncState 可获取到此对象，上面的 ctx 也可获取到此对象_cts.Token // 关联的 CancellationToken 对象，用于取消操作);// 开始执行任务task.Start();// task.Wait(); 在当前线程上等待任务执行完lblMsg.Text = "执行了一个没有返回值的任务，3 秒后执行完毕";// 任务执行完毕后的处理（注：ContinueWith 方法支持任意次回调，即可以写多个 task.ContinueWith() 都会被回调）task.ContinueWith((ctx) => // 任务执行完毕后所调用的方法{if (ctx.IsCanceled) // 任务被取消{var ignored = Dispatcher.RunAsync(CoreDispatcherPriority.High,() =>{lblMsg.Text += Environment.NewLine;lblMsg.Text += "取消了“执行一个没有返回值的任务”";});}if (ctx.IsFaulted) // 任务发生了一个未处理异常{var ignored = Dispatcher.RunAsync(CoreDispatcherPriority.High,() =>{lblMsg.Text += Environment.NewLine;lblMsg.Text += "“执行一个没有返回值的任务”发生了一个未处理异常";});}if (ctx.IsCompleted) // 任务已完成（任务成功地执行完毕或被取消或发生了未处理异常都会 ctx.IsCompleted == true）{var ignored = Dispatcher.RunAsync(CoreDispatcherPriority.High,() =>{lblMsg.Text += Environment.NewLine;lblMsg.Text += "“执行一个没有返回值的任务”执行完成，taskId: " + ctx.Id.ToString();});}});}private void btnCancelTask_Click_1(object sender, RoutedEventArgs e){// 发出取消操作的请求_cts.Cancel();// _cts.CancelAfter(1000); // 1000 毫秒后发出取消操作的请求}private void btnCreateTaskWithReturn_Click_1(object sender, RoutedEventArgs e){_cts = new CancellationTokenSource();Func<object, string> handler = delegate(object state) // state 是传递过来的上下文对象{// 在当前线程上阻塞 3000 毫秒（当收到取消请求时会发出信号，停止阻塞）_cts.Token.WaitHandle.WaitOne(3000);// 收到取消操作的请求后抛出一个 OperationCanceledException 异常，其会导致 task.IsCanceled 的值变为 true// 此处的代码等同于 _cts.Token.ThrowIfCancellationRequested();if (_cts.IsCancellationRequested)throw new OperationCanceledException(_cts.Token);return "我是“执行一个带返回值的任务”的返回值";};// Task.Factory.StartNew() - 创建任务并马上执行，可随时通过 task.Status 获取任务状态// Task.Run() 同样是创建任务并马上执行Task<string> task = Task.Factory.StartNew<string>(handler, // 任务所调用的方法，带返回值null, // 上下文对象，task.AsyncState 可获取到此对象_cts.Token // 关联的 CancellationToken 对象，用于取消操作);lblMsg.Text = "执行了一个带返回值的任务，3 秒后执行完毕";// 任务执行完毕后的处理（注：ContinueWith 方法支持任意次回调，即可以写多个 task.ContinueWith() 都会被回调）task.ContinueWith((ctx) =>{if (ctx.IsCanceled) // 任务被取消{var ignored = Dispatcher.RunAsync(CoreDispatcherPriority.High,() =>{lblMsg.Text += Environment.NewLine;lblMsg.Text += "取消了“执行一个带返回值的任务”";});}if (ctx.IsFaulted) // 任务发生了一个未处理异常{var ignored = Dispatcher.RunAsync(CoreDispatcherPriority.High,() =>{lblMsg.Text += Environment.NewLine;lblMsg.Text += "“执行一个带返回值的任务”发生了一个未处理异常";});}if (ctx.IsCompleted) // 任务已完成（任务成功地执行完毕或被取消或发生了未处理异常都会 ctx.IsCompleted == true）{var ignored = Dispatcher.RunAsync(CoreDispatcherPriority.High,() =>{lblMsg.Text += Environment.NewLine;lblMsg.Text += "“执行一个带返回值的任务”执行完成，taskId: " + ctx.Id.ToString();});// 当任务成功地执行完毕时，输出任务的返回值if (!ctx.IsCanceled && !ctx.IsFaulted){ignored = Dispatcher.RunAsync(CoreDispatcherPriority.High,() =>{lblMsg.Text += Environment.NewLine;// 任务的返回值lblMsg.Text += ctx.Result;});}}});}private void btnCancelTaskWithReturn_Click_1(object sender, RoutedEventArgs e){// 发出取消操作的请求_cts.Cancel();// _cts.CancelAfter(1000); // 1000 毫秒后发出取消操作的请求}}
}

<Pagex:Class="XamlDemo.Thread.Tasks.MultiTask"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:local="using:XamlDemo.Thread.Tasks"xmlns:d="http://schemas.microsoft.com/expression/blend/2008"xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"mc:Ignorable="d"><Grid Background="Transparent"><StackPanel Margin="120 0 0 0"><TextBlock Name="lblMsg" FontSize="14.667" /><Button Name="btnCreateMultiTask" Content="任务并行执行" Click="btnCreateMultiTask_Click_1" Margin="0 10 0 0" /></StackPanel></Grid>
</Page>

/** 演示多 Task 的并行执行* * 注：* 本例中同时创建了三个任务 task1, task2, task3，但是由于 Task 是基于线程池的，所以三个任务的启动时间是不一样的，启动顺序是不一定的* 启动顺序可能是 task1->task2->task3，也可能是 task3->task2->task1，也可能是 task2->task3->task1，等等等等都有可能，是不一定的*/using System;
using System.Threading.Tasks;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;namespace XamlDemo.Thread.Tasks
{public sealed partial class MultiTask : Page{private static int _count = 0;public MultiTask(){this.InitializeComponent();}private void btnCreateMultiTask_Click_1(object sender, RoutedEventArgs e){// 创建并执行任务1Task task1 = Task.Run(() =>{new System.Threading.ManualResetEvent(false).WaitOne(3000);System.Threading.Interlocked.Increment(ref _count);});// 创建并执行任务2Task task2 = Task.Run(() =>{new System.Threading.ManualResetEvent(false).WaitOne(3000);System.Threading.Interlocked.Increment(ref _count);});// 创建并执行任务3Task task3 = Task.Run(() =>{new System.Threading.ManualResetEvent(false).WaitOne(3000);System.Threading.Interlocked.Increment(ref _count);});// 将所有任务合成一个 Task 对象，不会阻塞 UI 线程，通过 task.ContinueWith() 获取结果Task task = Task.WhenAll(task1, task2, task3);// Task.WaitAll(task1, task2, task3); 等待所有任务完成，会阻塞 UI 线程DateTime dt = DateTime.Now;// task 执行完毕后的处理，即所有任务执行完毕后的处理task.ContinueWith((ctx) =>{var ignored = Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.High,() =>{lblMsg.Text = "count: " + _count.ToString() + ", 执行时间: " + (DateTime.Now - dt).TotalSeconds.ToString() + "秒";});});}}
}

<Pagex:Class="XamlDemo.Thread.Tasks.ParallelDemo"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:local="using:XamlDemo.Thread.Tasks"xmlns:d="http://schemas.microsoft.com/expression/blend/2008"xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"mc:Ignorable="d"><Grid Background="Transparent"><StackPanel Margin="120 0 0 0"><TextBlock Name="lblMsg1" FontSize="14.667" /><TextBlock Name="lblMsg2" FontSize="14.667" /><Button Name="btnCreateParallel" Content="执行一个并行运算（Parallel）" Click="btnCreateParallel_Click_1" Margin="0 10 0 0" /><Button Name="btnCancelParallel" Content="取消" Click="btnCancelParallel_Click_1" Margin="0 10 0 0" /></StackPanel></Grid>
</Page>

/** Parallel - 并行计算（在 System.Threading.Tasks 命名空间下）* * Parallel.For() - for 循环的并行运算 * Parallel.ForEach() - foreach 循环的并行运算 * Parallel.Invoke() - 并行调用多个 Action* PLINQ - LINQ to Object 的并行运算* * * 本例通过 Parallel.Invoke() 来演示并行运算* 其它并行运算的说明参见：http://www.cnblogs.com/webabcd/archive/2010/06/03/1750449.html*/using System.Threading;
using System.Threading.Tasks;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;namespace XamlDemo.Thread.Tasks
{public sealed partial class ParallelDemo : Page{private CancellationTokenSource _cts;public ParallelDemo(){this.InitializeComponent();}private void btnCreateParallel_Click_1(object sender, RoutedEventArgs e){if (_cts != null)_cts.Cancel();_cts = new CancellationTokenSource();// Parallel 的相关配置ParallelOptions parallelOptions = new ParallelOptions() {CancellationToken = _cts.Token, // Parallel 关联的 CancellationToken 对象，用于取消操作MaxDegreeOfParallelism = 10 // Parallel 的最大并行数};// 并行执行多个 Action（不支持 Func）Parallel.Invoke(parallelOptions,() =>Task1(parallelOptions.CancellationToken),() =>Task2(parallelOptions.CancellationToken));}// Action 1private void Task1(CancellationToken token){Task task = Task.Factory.StartNew(() =>{int count = 0;// 未被取消则一直运行while (!token.IsCancellationRequested){count++;var ignored = Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.High,() =>{lblMsg1.Text = "count1: " + count.ToString();});token.WaitHandle.WaitOne(100);}},token);}// Action 2private void Task2(CancellationToken token){Task task = Task.Factory.StartNew(() =>{int count = 0;// 未被取消则一直运行while (!token.IsCancellationRequested){count++;var ignored = Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.High,() =>{lblMsg2.Text = "count2: " + count.ToString();});token.WaitHandle.WaitOne(100);}},token);}// 取消并行运算private void btnCancelParallel_Click_1(object sender, RoutedEventArgs e){if (_cts != null)_cts.Cancel();}}
}