注册任务

/// <summary>
/// Registers a background task in the system waiting to trigger
/// </summary>
/// <param name="taskName">Name of the task. Has to be unique</param>
/// <param name="taskEntryPoint">Entry point (Namespace) of the class (has to implement IBackgroundTask and has to be in a Windows Runtime Component) to start</param>
/// <param name="trigger">What has to be triggered to start the task</param>
/// <param name="condition">Optional condition. Can be null</param>
/// <param name="recreateIfExists">Should the Task be recreated if it already exists?</param>
/// <returns></returns>
public BackgroundTaskRegistration RegisterTask(string taskName, string taskEntryPoint, IBackgroundTrigger trigger, IBackgroundCondition condition = null) {
    Debug.WriteLine("Try registering task: " + taskName);

    var builder = new BackgroundTaskBuilder {
        Name = taskName,
        TaskEntryPoint = taskEntryPoint
    };

    builder.SetTrigger(trigger);

    if (condition != null) {
        builder.AddCondition(condition);
    }

    try {
        var task = builder.Register();
        Debug.WriteLine("Task successfully registered");
        return task;
    } catch (Exception exception) {
        Debug.WriteLine("Error creating Task: " + exception);
        return null;
    }
}