无法注册时间触发的后台任务

Question

对于Windows 8应用程序,在C#/ Xaml中我尝试注册后台任务.这很难说,但我想我的后台任务已被注册,但当我在调试位置工具栏上点击后台任务的名称时,我的应用程序停止工作,没有任何消息.

我查看了事件查看器上的日志,我得到:"带有入口点MyApp.Pages.SampleBackgroundTask和名称示例每小时后台任务的后台任务无法激活,错误代码为0x80010008."

这是我的代码:

   private async void Button_Click_BackgroundTask(object sender, RoutedEventArgs e)
    {
        string entryPoint = "MyApp.Pages.SampleBackgroundTask";
        string taskName = "Example hourly background task";
        TimeTrigger hourlyTrigger = new TimeTrigger(60, false);

        BackgroundTaskRegistration myBackGroundTaskRegistration =   RegisterBackgroundTask(entryPoint, taskName, hourlyTrigger, null);
        if(myBackGroundTaskRegistration != null)
        AttachProgressAndCompletedHandlers(myBackGroundTaskRegistration);
    }


   public static BackgroundTaskRegistration RegisterBackgroundTask(String taskEntryPoint,
                                                                    String name,
                                                                    IBackgroundTrigger trigger,
                                                                    IBackgroundCondition condition)
    {

        var taskRegistered = false;
        var iter = Windows.ApplicationModel.Background.BackgroundTaskRegistration.AllTasks;

        foreach (var item in iter)
        {
            var task = item.Value;
            if (task.Name == name)
            {
                taskRegistered = true;
                return item.Value as BackgroundTaskRegistration;
            }
        }


        var builder = new BackgroundTaskBuilder();

        builder.Name = name;
        builder.TaskEntryPoint = taskEntryPoint;
        builder.SetTrigger(trigger);

        if (condition != null)
        {

            builder.AddCondition(condition);
        }

        BackgroundTaskRegistration taskBack = builder.Register();

        return taskBack;
    }


       private void AttachProgressAndCompletedHandlers(IBackgroundTaskRegistration task)
    {
        task.Progress += new BackgroundTaskProgressEventHandler(OnProgress);
        task.Completed += new BackgroundTaskCompletedEventHandler(OnCompleted);
    }


  private void OnProgress(IBackgroundTaskRegistration task, BackgroundTaskProgressEventArgs args)
    {
        var progress = "Progress: " + args.Progress + "%";

    }


    private void OnCompleted(IBackgroundTaskRegistration task, BackgroundTaskCompletedEventArgs args)
    {
        Debug.WriteLine("Hi");
    }

我在清单中添加了这个:

      <Extension Category="windows.backgroundTasks" EntryPoint="MyApp.Pages.SampleBackgroundTask">
      <BackgroundTasks>
        <Task Type="timer" />
      </BackgroundTasks>
    </Extension>

我忘记了什么吗？

谢谢您的帮助.

编辑:这是我的任务的代码,在我的项目页面之一:

      public sealed class SampleBackgroundTask : IBackgroundTask
{
    public void Run(IBackgroundTaskInstance taskInstance)
    {
        BackgroundTaskDeferral _deferral = taskInstance.GetDeferral();

        _deferral.Complete();
    }
}

Answer 1

我也有这个问题.我在同一个项目中也有我的.我终于通过将任务转移到一个单独的项目来实现它.我不得不将项目输出设置为Windows运行时组件(在属性应用程序选项卡下).另外不要忘记添加项目作为参考.