我正在按照https://learn.microsoft.com/zh-cn/windows/uwp/launch-resume/create-and-register-a-background-task文档创建一个后台任务,该任务将每15分钟运行一次并ping一个服务。
Created a Windows Runtime Component project with a public sealed class implementing IBackgroundTask
namespace PeriodicBackgroundTask { public sealed class FifteenMinutePeriodicTimer : IBackgroundTask { private static readonly FileLogWriter mWriteLogToFile = new FileLogWriter(); public FifteenMinutePeriodicTimer() { } public void Run(IBackgroundTaskInstance taskInstance) { try { taskInstance.Canceled += new BackgroundTaskCanceledEventHandler(OnCanceled); mDeferral = taskInstance.GetDeferral(); mWriteLogToFile.log("Starting periodic timer at " + DateTime.Now.ToString()); // Calling method to do a Post call to a service. mWriteLogToFile.log("Finishing periodic timer at " + DateTime.Now.ToString()); } catch (Exception ex) { mWriteLogToFile.log("Fifteen Minute periodic timer failed.", ex); } finally { // Adding some buffer for async processes to finish. Task.Delay(TimeSpan.FromSeconds(15)).Wait(); mDeferral.Complete(); } } private void OnCanceled(IBackgroundTaskInstance sender, BackgroundTaskCancellationReason reason) { mWriteLogToFile.log("Fifteen minute periodic timer is canceled. {0}", reason.ToString()); } } }
Entry in UWP application's Package.appmanifest file
<Extension Category="windows.backgroundTasks" EntryPoint="PeriodicBackgroundTask.FifteenMinutePeriodicTimer"> <BackgroundTasks> <Task Type="systemEvent" /> <Task Type="timer" /> </BackgroundTasks> </Extension>
Registering Timer at the beginning of OnLaunched Method in App.xaml.cs
public async static Task RegisterBackgroundTask() { foreach (var task in BackgroundTaskRegistration.AllTasks) { if (String.Equals(task.Value.Name, TASK_NAME)) { mWriteLogToFile.log("Old version of fifteen minute periodic timer found. Unregistering it."); BackgroundExecutionManager.RemoveAccess(); // Unregistering so that any update in Background task can be applied. task.Value.Unregister(true); break; } } BackgroundAccessStatus backgroundAccessStatus = await BackgroundExecutionManager.RequestAccessAsync(); if (backgroundAccessStatus == BackgroundAccessStatus.DeniedByUser || backgroundAccessStatus == BackgroundAccessStatus.DeniedBySystemPolicy) { mWriteLogToFile.log("Fifteen minute periodic timer registration failed, due to Request access status."); return; } BackgroundTaskBuilder builder = new BackgroundTaskBuilder(); builder.Name = TASK_NAME; builder.TaskEntryPoint = "PeriodicBackgroundTask.FifteenMinutePeriodicTimer"; builder.SetTrigger(new TimeTrigger(15, false)); builder.CancelOnConditionLoss = false; var backgroundTask = builder.Register(); if (backgroundTask != null) { mWriteLogToFile.log("Fifteen minute periodic timer registration SUCCESSFUL."); } else { mWriteLogToFile.log("Fifteen minute periodic timer registration FAILED."); } }
更多信息:
Windows版本:1607 Microsoft.NETCore.UniversalWindowsPlatform版本:5.1.0