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Windows 8 Store Apps学习（45） 多线程之异步编程: IAsyncAction2013-12-10 cnblogs webabcd多线程之异步编程: IAsyncAction, IAsyncOperation

重新想象 Windows 8 Store Apps （45） - 多线程之异步编程: IAsyncAction, IAsyncOperation, IAsyncActionWithProgress, IAsyncOperationWithProgress

介绍

重新想象 Windows 8 Store Apps 之 异步编程

IAsyncAction - 无返回值，无进度值

IAsyncOperation - 有返回值，无进度值

IAsyncActionWithProgress - 无返回值，有进度值

IAsyncOperationWithProgress - 有返回 值，有进度值

示例

1、演示 IAsyncAction（无返回值，无进度值）的用法

Thread/Async/IAsyncActionDemo.xaml

<Pagex:Class="XamlDemo.Thread.Async.IAsyncActionDemo"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:local="using:XamlDemo.Thread.Async"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="btnCreateAsyncAction" Content="执行一个 IAsyncAction" Click="btnCreateAsyncAction_Click_1" Margin="0 10 0 0" /><Button Name="btnCancelAsyncAction" Content="取消" Click="btnCancelAsyncAction_Click_1" Margin="0 10 0 0" /></StackPanel></Grid></Page>

Thread/Async/IAsyncActionDemo.xaml.cs

/* * 演示 IAsyncAction（无返回值，无进度值）的用法 ** 注： * 1、WinRT 中的异步功能均源自 IAsyncInfo * 2、IAsyncAction, IAsyncOperation<TResult>, IAsyncActionWithProgress<TProgress>, IAsyncOperationWithProgress<TResult, TProgress> 均继承自 IAsyncInfo *** 另： * Windows.System.Threading.ThreadPool.RunAsync（） - 返回的就是 IAsyncAction */using System.Runtime.InteropServices.WindowsRuntime;using System.Threading.Tasks;using Windows.Foundation;using Windows.UI.Xaml;using Windows.UI.Xaml.Controls;namespace XamlDemo.Thread.Async{public sealed partial class IAsyncActionDemo : Page{private IAsyncAction _action;public IAsyncActionDemo（）{this.InitializeComponent（）;}private IAsyncAction GetAsyncAction（）{// 通过 System.Runtime.InteropServices.WindowsRuntime.AsyncInfo 创建 IAsyncActionreturn AsyncInfo.Run（（token） => // CancellationToken tokenTask.Run（（） =>{token.WaitHandle.WaitOne（3000）;token.ThrowIfCancellationRequested（）;},token））;}private void btnCreateAsyncAction_Click_1（object sender, RoutedEventArgs e）{_action = GetAsyncAction（）;// 可以 await _action // IAsyncAction 完成后_action.Completed =（asyncInfo, asyncStatus） => // IAsyncAction asyncInfo, AsyncStatus asyncStatus{// AsyncStatus 包括：Started, Completed, Canceled, ErrorlblMsg.Text = "完成了，AsyncStatus: " + asyncStatus.ToString（）;};lblMsg.Text = "开始执行，3 秒后完成";}// 取消 IAsyncActionprivate void btnCancelAsyncAction_Click_1（object sender, RoutedEventArgs e）{if （_action ！= null）_action.Cancel（）;}}}