锁屏图像在测试版应用程序中不会更改

我在Windows Phone 8中创建了一个应用程序，该应用程序可以从后台任务更改锁屏图像。当运行代码时，该应用程序在模拟器和设备中运行良好。它包含launchforTest（），它使锁屏每30秒更改一次。

我收到一些评论，告诉 launchforTest（） 在应用程序通过商店上传时不起作用。 它基本上是为了测试目的。

所以我的问题是，当我从我进行beta测试的商店安装我的应用程序时，后台任务不起作用，即锁屏图像不会改变

我在代码中缺少什么，使其无法正常工作，请帮助。

这是我的代码

私有资源密集型任务资源

密集型任务; 私有字符串资源密集任务名称 = "智能锁屏计划任务代理"; 私有字符串资源密集任务说明 ="显示最新交易。

private StartTask()
{
    LockScreenChange("ms-appdata:///Local/Image0.jpg", true);
}
private async void LockScreenChange(string filePathOfTheImage, bool isAppResource)
{
    if (!LockScreenManager.IsProvidedByCurrentApplication)
    {
        // If you're not the provider, this call will prompt the user for permission.
        // Calling RequestAccessAsync from a background agent is not allowed.
        await LockScreenManager.RequestAccessAsync();
    }
    // Only do further work if the access is granted.
    if (LockScreenManager.IsProvidedByCurrentApplication)
    {
        // At this stage, the app is the active lock screen background provider.
        // The following code example shows the new URI schema.
        // ms-appdata points to the root of the local app data folder.
        // ms-appx points to the Local app install folder, to reference resources bundled in the XAP package
        // var schema = isAppResource ? "ms-appx:///" : "ms-appdata:///Local/";
        var uri = new Uri(filePathOfTheImage, UriKind.Absolute);
        // Set the lock screen background image.
        LockScreen.SetImageUri(uri);
        // Get the URI of the lock screen background image.
        var currentImage = LockScreen.GetImageUri();
        System.Diagnostics.Debug.WriteLine("The new lock screen background image is set to {0}", currentImage.ToString());
        UpdatePrimaryTile();
        StartResourceIntensiveAgent();// StartPeriodicAgent();//
        // MessageBox.Show("Lock screen changed. Click F12 or go to lock screen.");
    }
    else
    {
        MessageBox.Show("Background can't be updated as you clicked no!!");
    }
}
public void RemoveResourceIntensiveAgent()
{
    try
    {
        if (resourceIntensiveTask != null)
        {
            ScheduledActionService.Remove(resourceIntensiveTaskName);
        }
    }
    catch (Exception)
    {
    }
}
/// <summary>
/// Code to start the resource intensive task
/// </summary>
private void StartResourceIntensiveAgent()
{
    // Variable for tracking enabled status of background agents for this app.
    agentsAreEnabled = true;
    resourceIntensiveTask = ScheduledActionService.Find(resourceIntensiveTaskName) as ResourceIntensiveTask;
    // If the task already exists and background agents are enabled for the
    // application, you must remove the task and then add it again to update 
    // the schedule.
    if (resourceIntensiveTask != null)
    {
        ScheduledActionService.Remove(resourceIntensiveTaskName);
    }
    resourceIntensiveTask = new ResourceIntensiveTask(resourceIntensiveTaskName);
    // The description is required for periodic agents. This is the string that the user
    // will see in the background services Settings page on the device.
    resourceIntensiveTask.Description = (resourceIntensiveTaskDescription);
    // Place the call to Add in a try block in case the user has disabled agents.
    try
    {
        ScheduledActionService.Add(resourceIntensiveTask);
        //ResourceIntensiveStackPanel.DataContext = resourceIntensiveTask;
        resourceIntensiveTask.ExpirationTime = DateTime.Now.AddDays(14);
        // If debugging is enabled, use LaunchForTest to launch the agent in one minute.
        ScheduledActionService.LaunchForTest(resourceIntensiveTaskName, TimeSpan.FromSeconds(30));
    }
    catch (InvalidOperationException exception)
    {
        if (exception.Message.Contains("BNS Error: The action is disabled"))
        {
            MessageBox.Show("Background agents for this application have been disabled by the user.");
            agentsAreEnabled = false;
        }
    }
    catch (SchedulerServiceException)
    {
        // No user action required.
    }
}