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背水一战 Windows 10 (115) - 后台任务: 通过 toast 激活后台任务, 定时激活后台任务

Posted on 2018-06-22 08:29 webabcd 阅读(...) 评论(...) 编辑 收藏

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背水一战 Windows 10 (115) - 后台任务: 通过 toast 激活后台任务, 定时激活后台任务



作者:webabcd


介绍
背水一战 Windows 10 之 后台任务

  • 通过 toast 激活后台任务
  • 定时激活后台任务



示例
1、演示如何通过 toast 激活后台任务
/BackgroundTaskLib/BackgroundTaskToast.cs

/*
 * 后台任务,用于演示如何通过 toast 激活后台任务 
 * 
 * ToastNotificationActionTriggerDetail - toast 触发器信息
 *     Argument - 由 toast 传递过来的参数
 *     UserInput - 由 toast 传递过来的输入框数据
 */

using System;
using Windows.ApplicationModel.Background;
using Windows.Storage;
using Windows.UI.Notifications;

namespace BackgroundTaskLib
{
    public sealed class BackgroundTaskToast : IBackgroundTask
    {
        public async void Run(IBackgroundTaskInstance taskInstance)
        {
            BackgroundTaskDeferral deferral = taskInstance.GetDeferral();

            try
            {
                // 获取 ToastNotificationActionTriggerDetail 对象
                ToastNotificationActionTriggerDetail toastDetail = taskInstance.TriggerDetails as ToastNotificationActionTriggerDetail;
                if (toastDetail != null)
                {
                    string result = "";

                    result = "argument: " + toastDetail.Argument;
                    result += Environment.NewLine;

                    foreach (string key in toastDetail.UserInput.Keys)
                    {
                        result += $"key:{key}, value:{toastDetail.UserInput[key]}";
                        result += Environment.NewLine;
                    }

                    // 将获取到的 toast 信息保存为文件
                    StorageFile file = await ApplicationData.Current.LocalFolder.CreateFileAsync(@"webabcdBackgroundTask\toast.txt", CreationCollisionOption.ReplaceExisting);
                    await FileIO.WriteTextAsync(file, result);
                }
            }
            finally
            {
                deferral.Complete();
            }
        }
    }
}

BackgroundTask/Toast.xaml

<Page
    x:Class="Windows10.BackgroundTask.Toast"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:Windows10.BackgroundTask"
    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="10 0 10 10">

            <Button Name="buttonShowToast" Content="显示 toast(点击 toast 框或点击 toast 中的按钮则可激活后台任务)" Click="buttonShowToast_Click" Margin="5" />

        </StackPanel>
    </Grid>
</Page>

BackgroundTask/Toast.xaml.cs

/*
 * 演示如何通过 toast 激活后台任务
 * 
 * 注:
 * 1、需要引用后台任务项目,相关代码参见 BackgroundTaskLib/BackgroundTaskToast.cs
 * 2、需要在 Package.appxmanifest 添加“后台任务”声明,支持的任务类型选择“常规”,并指定 EntryPoint(后台任务的类全名),类似如下:
 * <Extension Category="windows.backgroundTasks" EntryPoint="BackgroundTaskLib.BackgroundTaskToast">
 *   <BackgroundTasks>
 *     <Task Type="general" />
 *   </BackgroundTasks>
 * </Extension>
 * 
 * 
 * 本例的 toast 的 xml 说明:
 * activationType - 通过点击 toast 激活 app 时的激活方式,background 代表后台方式激活
 * 其他 toast 的相关知识点请参见:/Notification/Toast/
 */

using System;
using System.Collections.Generic;
using Windows.ApplicationModel;
using Windows.ApplicationModel.Background;
using Windows.Data.Xml.Dom;
using Windows.Storage;
using Windows.UI.Notifications;
using Windows.UI.Popups;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;

namespace Windows10.BackgroundTask
{
    public sealed partial class Toast : Page
    {
        private string _taskName = "Toast";
        private string _taskEntryPoint = "BackgroundTaskLib.BackgroundTaskToast";

        public Toast()
        {
            this.InitializeComponent();
        }

        protected async override void OnNavigatedTo(NavigationEventArgs e)
        {
            base.OnNavigatedTo(e);


            // 在注册后台任务之前,需要调用 BackgroundExecutionManager.RequestAccessAsync(),如果是更新过的 app 则在之前还需要调用 BackgroundExecutionManager.RemoveAccess()
            string appVersion = $"{Package.Current.Id.Version.Major}.{Package.Current.Id.Version.Minor}.{Package.Current.Id.Version.Build}.{Package.Current.Id.Version.Revision}";
            if ((string)ApplicationData.Current.LocalSettings.Values["AppVersion"] != appVersion)
            {
                // 对于更新的 app 来说先要调用这个方法
                BackgroundExecutionManager.RemoveAccess();
                // 注册后台任务之前先要调用这个方法,并获取 BackgroundAccessStatus 状态
                BackgroundAccessStatus status = await BackgroundExecutionManager.RequestAccessAsync();
                if (status == BackgroundAccessStatus.Unspecified || status == BackgroundAccessStatus.DeniedBySystemPolicy || status == BackgroundAccessStatus.DeniedByUser)
                {
                    // 无权限注册后台任务

                    await new MessageDialog("没有权限注册后台任务").ShowAsync();
                }
                else
                {
                    // 有权限注册后台任务

                    ApplicationData.Current.LocalSettings.Values["AppVersion"] = appVersion;
                }
            }


            // 如果任务已注册,则注销
            foreach (KeyValuePair<Guid, IBackgroundTaskRegistration> t in BackgroundTaskRegistration.AllTasks)
            {
                if (t.Value.Name == _taskName)
                {
                    t.Value.Unregister(true);
                }
            }

            BackgroundTaskBuilder builder = new BackgroundTaskBuilder
            {
                Name = _taskName,
                TaskEntryPoint = _taskEntryPoint
            };
            // 指定后台任务的触发器类型为 ToastNotificationActionTrigger(即通过 toast 激活)
            builder.SetTrigger(new ToastNotificationActionTrigger());
            // 注册后台任务
            BackgroundTaskRegistration task = builder.Register();
        }

        // 弹出 toast 通知(点击 toast 框或点击 toast 中的按钮则可激活后台任务)
        private void buttonShowToast_Click(object sender, RoutedEventArgs e)
        {
            string toastXml = @"
                <toast activationType='background' launch='launch arguments'>
                    <visual>
                        <binding template='ToastGeneric'>
                            <text>toast - title</text>
                            <text>toast - content</text>
                        </binding>
                    </visual>
                    <actions>
                        <input type='text' id='message1' title='title1' />
                        <action content='确认' activationType='background' arguments='action arguments'/>
                    </actions>
                </toast>";

            XmlDocument toastDoc = new XmlDocument();
            toastDoc.LoadXml(toastXml);

            ToastNotification toast = new ToastNotification(toastDoc);
            ToastNotificationManager.CreateToastNotifier().Show(toast);
        }
    }
}


2、演示后台任务的应用(定时激活后台任务)
/BackgroundTaskLib/BackgroundTaskTime.cs

/*
 * 后台任务,用于演示如何定时激活后台任务
 */

using System;
using Windows.ApplicationModel.Background;
using Windows.Storage;

namespace BackgroundTaskLib
{
    // 实现 IBackgroundTask 接口,其只有一个方法,即 Run()
    public sealed class BackgroundTaskTime : IBackgroundTask
    {
        public async void Run(IBackgroundTaskInstance taskInstance)
        {
            // 异步操作
            BackgroundTaskDeferral deferral = taskInstance.GetDeferral();

            try
            {
                // 写入相关数据到文件
                StorageFile file = await ApplicationData.Current.LocalFolder.CreateFileAsync(@"webabcdBackgroundTask\time.txt", CreationCollisionOption.ReplaceExisting);
                await FileIO.AppendTextAsync(file, "background task timeTrigger or maintenanceTrigger: " + DateTime.Now.ToString() + Environment.NewLine);

            }
            finally
            {
                // 完成异步操作
                deferral.Complete();
            }
        }
    }
}

BackgroundTask/Time.xaml

<Page
    x:Class="Windows10.BackgroundTask.Time"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:Windows10.BackgroundTask"
    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="10 0 10 10">

            <Button Name="btnRegister" Content="注册一个后台任务" Margin="5" Click="btnRegister_Click" />
            <Button Name="btnUnregister" Content="注销指定的后台任务" Margin="5" Click="btnUnregister_Click" />

        </StackPanel>
    </Grid>
</Page>

BackgroundTask/Time.xaml.cs

/*
 * 演示后台任务的应用(定时激活后台任务)
 * 
 * 注:
 * 1、需要引用后台任务项目,相关代码参见 BackgroundTaskLib/BackgroundTaskTime.cs
 * 2、需要在 Package.appxmanifest 添加“后台任务”声明,支持的任务类型选择“计时器”,并指定 EntryPoint(后台任务的类全名),类似如下:
 * <Extension Category="windows.backgroundTasks" EntryPoint="BackgroundTaskLib.BackgroundTaskTime">
 *   <BackgroundTasks>
 *     <Task Type="timer" />
 *   </BackgroundTasks>
 * </Extension>
 */

using System;
using System.Collections.Generic;
using Windows.ApplicationModel;
using Windows.ApplicationModel.Background;
using Windows.Storage;
using Windows.UI.Core;
using Windows.UI.Popups;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;

namespace Windows10.BackgroundTask
{
    public sealed partial class Time : Page
    {
        // 所注册的后台任务的名称
        private string _taskName = "Time";

        // 所注册的后台任务的 EntryPoint,即后台任务的类全名
        private string _taskEntryPoint = "BackgroundTaskLib.BackgroundTaskTime";

        // 后台任务是否已在系统中注册
        private bool _taskRegistered = false;

        public Time()
        {
            this.InitializeComponent();
        }

        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
            // 遍历所有已注册的后台任务
            foreach (KeyValuePair<Guid, IBackgroundTaskRegistration> task in BackgroundTaskRegistration.AllTasks)
            {
                if (task.Value.Name == _taskName)
                {
                    _taskRegistered = true;
                    break;
                }
            }

            UpdateUI();
        }

        private async void btnRegister_Click(object sender, RoutedEventArgs e)
        {
            // 在注册后台任务之前,需要调用 BackgroundExecutionManager.RequestAccessAsync(),如果是更新过的 app 则在之前还需要调用 BackgroundExecutionManager.RemoveAccess()
            string appVersion = $"{Package.Current.Id.Version.Major}.{Package.Current.Id.Version.Minor}.{Package.Current.Id.Version.Build}.{Package.Current.Id.Version.Revision}";
            if ((string)ApplicationData.Current.LocalSettings.Values["AppVersion"] != appVersion)
            {
                // 对于更新的 app 来说先要调用这个方法
                BackgroundExecutionManager.RemoveAccess();
                // 注册后台任务之前先要调用这个方法,并获取 BackgroundAccessStatus 状态
                BackgroundAccessStatus status = await BackgroundExecutionManager.RequestAccessAsync();
                if (status == BackgroundAccessStatus.Unspecified || status == BackgroundAccessStatus.DeniedBySystemPolicy || status == BackgroundAccessStatus.DeniedByUser)
                {
                    // 无权限注册后台任务

                    await new MessageDialog("没有权限注册后台任务").ShowAsync();
                }
                else
                {
                    // 有权限注册后台任务

                    ApplicationData.Current.LocalSettings.Values["AppVersion"] = appVersion;
                }
            }


            // 用于构造一个后台任务
            BackgroundTaskBuilder builder = new BackgroundTaskBuilder()
            {
                Name = _taskName,
                TaskEntryPoint = _taskEntryPoint

            };
            // 指定后台任务的触发器类型为 MaintenanceTrigger(定时激活,最小周期 15 分钟)
            builder.SetTrigger(new MaintenanceTrigger(15, false));
            // 注册后台任务
            BackgroundTaskRegistration task = builder.Register();
            
            _taskRegistered = true;

            UpdateUI();
        }

        private void btnUnregister_Click(object sender, RoutedEventArgs e)
        {
            // 遍历所有已注册的后台任务
            foreach (KeyValuePair<Guid, IBackgroundTaskRegistration> task in BackgroundTaskRegistration.AllTasks)
            {
                if (task.Value.Name == _taskName)
                {
                    // 从系统中注销指定的后台任务。唯一一个参数代表如果当前后台任务正在运行中,是否需要将其取消
                    task.Value.Unregister(true);
                    break;
                }
            }

            _taskRegistered = false;

            UpdateUI();
        }


        private async void UpdateUI()
        {
            await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
            {
                btnRegister.IsEnabled = !_taskRegistered;
                btnUnregister.IsEnabled = _taskRegistered;
            });
        }
    }
}



OK
[源码下载]