UWP-动态磁贴

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Windows.ApplicationModel.Background;
using Windows.Data.Xml.Dom;
using Windows.UI.Notifications;
using Windows.Web.Syndication;

namespace BackgroundTasks
{
    public sealed class BlogFeedBackgroundTask  : IBackgroundTask
    {
//首先，我们处理一下获取IT追梦园的RSS订阅，返回XML文档的方法。前两个是设置一下网络请求头的信息。（可以忽略）
         static string customHeaderName = "User-Agent"; 
         static string customHeaderValue = "Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; 
         WOW64; Trident/6.0)"; 
//这里是IT追梦园的RSS地址：
         static string feedUrl = @"http://www.zmy123.cn/?feed=rss2";
//这里获取它节点为text的值
         static string textElementName = "text";
      

//注意：这里是后台任务的开始，等我们写完代码，在这里打断点调试，看后台任务是否可以进行到这里！
        public async void Run( IBackgroundTaskInstance taskInstance )
        {
          
            BackgroundTaskDeferral deferral = taskInstance.GetDeferral();

            var feed = await GetBlogFeed();

            UpdateTile( feed );

            deferral.Complete();
        }

        private static async Task<SyndicationFeed> GetBlogFeed()
        {
            SyndicationFeed feed = null;

            try
            {
//这里都是请求最线XML地址的方法，并获取到XML文档。
                SyndicationClient client = new SyndicationClient();
                client.BypassCacheOnRetrieve = true;
                client.SetRequestHeader( customHeaderName, customHeaderValue );
//这里我们获取到了XML文档 feed
                feed = await client.RetrieveFeedAsync( new Uri( feedUrl ) );
            }
            catch( Exception ex )
            {
                Debug.WriteLine( ex.ToString() );
            }

            return feed;
        }

//更新磁贴的方法
        private static void UpdateTile( SyndicationFeed feed )
        {
//通过这个方法，我们就可以为动态磁贴的添加做基础。
            var updater = TileUpdateManager.CreateTileUpdaterForApplication();

//这里设置的是所以磁贴都可以为动态
            updater.EnableNotificationQueue( true );
            updater.Clear();
            int itemCount = 0;

//然后这里是重点：记得分3步走：
            foreach( var item in feed.Items )
            {
//1：创建xml对象，这里看你想显示几种动态磁贴，如果想显示正方形和长方形的，那就分别设置一个动态磁贴类型即可。
//下面这两个分别是矩形的动态磁贴，和方形的动态磁贴，具体样式，自己可以去微软官网查一查。我这里用到的是换行的文字形式。
                XmlDocument tileXml = TileUpdateManager.GetTemplateContent( TileTemplateType.TileWideText03 );
                XmlDocument tilexml2 = TileUpdateManager.GetTemplateContent(TileTemplateType.TileSquareText04);
                var title = item.Title;
                string titleText = title.Text == null ? String.Empty : title.Text;
//2.接着给这个xml对象赋值
                tileXml.GetElementsByTagName( textElementName )[0].InnerText = titleText;

//3.然后用Update方法来更新这个磁贴
                updater.Update( new TileNotification( tileXml ) );

//4.最后这里需要注意的是微软规定动态磁贴的队列数目小于5个，所以这里做出判断。
                if( itemCount++ > 5 ) break;
            }
        }
      
    }
}

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Windows.ApplicationModel.Background;
using Windows.Data.Xml.Dom;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;
using Windows.Web.Syndication;

// The Blank Page item template is documented at http://go.microsoft.com/fwlink/p/?LinkID=234238

namespace ContosoApp
{
    /// <summary>
    /// An empty page that can be used on its own or navigated to within a Frame.
    /// </summary>
    public sealed partial class MainPage : Page
    {
        public MainPage()
        {
            this.InitializeComponent();
        }

        protected override void OnNavigatedTo( NavigationEventArgs e )
        {
//在这里注册我们那个运行时组件里的后台任务。
            this.RegisterBackgroundTask();
        }


        private async void RegisterBackgroundTask()
        {
//这里就是磁贴更新周期的一些逻辑处理
            var backgroundAccessStatus = await BackgroundExecutionManager.RequestAccessAsync();
            if( backgroundAccessStatus == BackgroundAccessStatus.AllowedMayUseActiveRealTimeConnectivity ||
                backgroundAccessStatus == BackgroundAccessStatus.AllowedWithAlwaysOnRealTimeConnectivity )
            {
                foreach( var task in BackgroundTaskRegistration.AllTasks )
                {
                    if( task.Value.Name == taskName )
                    {
                        task.Value.Unregister( true );
                    }
                }

                BackgroundTaskBuilder taskBuilder = new BackgroundTaskBuilder();
                taskBuilder.Name = taskName;
                taskBuilder.TaskEntryPoint = taskEntryPoint;
                taskBuilder.SetTrigger( new TimeTrigger( 15, false ) );
                var registration = taskBuilder.Register();
            }
        }

        private const string taskName = "BlogFeedBackgroundTask";
        private const string taskEntryPoint = "BackgroundTasks.BlogFeedBackgroundTask";
    }
}