Question

我正试图在电话离开或进入地理围栏位置（在其他地方设置并传入）时显示Tooast。问题是，当应用程序在后台时，触发器不会发生，我也看不到showToast消息。我正在使用PC上的模拟器手动更改位置。

后台任务＆gt;位置设置在应用清单下。

这是我用来构建Geofence和backgroundtask的代码

//Creates Geofence and names it "PetsnikkerVacationFence"
public static async Task SetupGeofence(double lat, double lon)
    {
        await RegisterBackgroundTasks();

        if (IsTaskRegistered())
        {

            BasicGeoposition position = new BasicGeoposition();
            position.Latitude = lat;
            position.Longitude = lon;

            double radius = 8046.72; //5 miles in meters
            Geocircle geocircle = new Geocircle(position, radius);
            MonitoredGeofenceStates monitoredStates = MonitoredGeofenceStates.Entered | MonitoredGeofenceStates.Exited;

            Geofence geofence = new Geofence("PetsnikkerVacationFence", geocircle, monitoredStates, false);

            GeofenceMonitor monitor = GeofenceMonitor.Current;

            var existingFence = monitor.Geofences.SingleOrDefault(f => f.Id == "PetsnikkerVacationFence");

            if (existingFence != null)
                monitor.Geofences.Remove(existingFence);

            monitor.Geofences.Add(geofence);

        }




    }

    //Registers the background task with a LocationTrigger
    static async Task RegisterBackgroundTasks()
    {
        var access = await BackgroundExecutionManager.RequestAccessAsync();


        if (access == BackgroundAccessStatus.Denied)
        {

        }
        else
        {
            var taskBuilder = new BackgroundTaskBuilder();
            taskBuilder.Name = "PetsnikkerVacationFence";

            taskBuilder.AddCondition(new SystemCondition(SystemConditionType.InternetAvailable));
            taskBuilder.SetTrigger(new LocationTrigger(LocationTriggerType.Geofence));

            taskBuilder.TaskEntryPoint = typeof(Petsnikker.Windows.Background.GeofenceTask).FullName;

            var registration = taskBuilder.Register();

            registration.Completed += (sender, e) =>
            {
                try
                {
                    e.CheckResult();
                }
                catch (Exception error)
                {
                    Debug.WriteLine(error);
                }
            };



        }

    }

    static bool IsTaskRegistered()
    {
        var Registered = false;
        var entry = BackgroundTaskRegistration.AllTasks.FirstOrDefault(keyval => keyval.Value.Name == "PetsnikkerVacationFence");
        if (entry.Value != null)
            Registered = true;
        return Registered;
    }
}
}

此代码是我监控地理围栏状态的地方。这是appxmanifest中的Entry点指向的地方

public sealed class GeofenceTask : IBackgroundTask
{
    public void Run(IBackgroundTaskInstance taskInstance)
    {

        var monitor = GeofenceMonitor.Current;
        if (monitor.Geofences.Any())
        {
            var reports = monitor.ReadReports();
            foreach (var report in reports)
            {


                switch (report.NewState)
                {
                    case GeofenceState.Entered:
                    {

                            ShowToast("Approaching Home",":-)");
                            break;
                    }
                    case GeofenceState.Exited:
                    {
                            ShowToast("Leaving Home", ":-)");
                            break;


                    }


                }
            }
        }


        //deferral.Complete();
    }

    private static void ShowToast(string firstLine, string secondLine)
    {
        var toastXmlContent =
          ToastNotificationManager.GetTemplateContent(ToastTemplateType.ToastText02);

        var txtNodes = toastXmlContent.GetElementsByTagName("text");
        txtNodes[0].AppendChild(toastXmlContent.CreateTextNode(firstLine));
        txtNodes[1].AppendChild(toastXmlContent.CreateTextNode(secondLine));

        var toast = new ToastNotification(toastXmlContent);
        var toastNotifier = ToastNotificationManager.CreateToastNotifier();
        toastNotifier.Show(toast);

        Debug.WriteLine("Toast: {0} {1}", firstLine, secondLine);
    }

}

Answer 1

查看代码后，您的代码似乎是正确的。

为了发射Geofence Backgroundtask以显示吐司信息，请确保以下事项：

1）请确保您已在Package.appxmanifest中完成所有必要的配置以注册BackgroundTask，例如您已设置正确的EntryPoint并添加了“Location”功能即可。

有关详细信息，您可以尝试将 Package.appxmanifest 与官方示例Geolocation的Package.appxmanifest进行比较。另请检查：Create and register a background task和Declare background tasks in the application manifest。

2）请确保您知道如何手动设置模拟器中的位置以模拟电话休假或输入地理围栏位置。有关如何在模拟器中设置位置的更多信息，请查看以下文章： https://msdn.microsoft.com/library/windows/apps/dn629629.aspx#location_and_driving。

3）请确保您在模拟器中的第二个位置与第一次定义的地理位置相距甚远，因为模拟器的行为类似于真实设备，并且设备不希望突然从纽约搬到西雅图。或者BackgroundTask不会立即触发。

4）地理围栏的后台任务无法比每2分钟更频繁地启动。如果在后台测试地理围栏，则模拟器能够自动启动后台任务。但是对于下一个后续后台任务，您需要等待超过2分钟。

此外，我建议您参考以下文章，了解如何使用Windows Phone模拟器测试具有地理围栏的应用程序： https://blogs.windows.com/buildingapps/2014/05/28/using-the-windows-phone-emulator-for-testing-apps-with-geofencing/。

感谢。

BackgroundTask地理围栏触发

1 个答案: