任务

public sealed class BackgroundTask : IBackgroundTask {

    private BackgroundTaskDeferral _deferral;

    /// <summary>
    /// Registers the listener to check if the button is pressed
    /// </summary>
    /// <param name="taskInstance">An interface to an instance of the background task. The system creates this instance when the task has been triggered to run.</param>
    public async void Run(IBackgroundTaskInstance taskInstance) {
        _deferral = taskInstance.GetDeferral();

        //Do async operations here

        _deferral.Complete();
    }
}