Question

我可以使用iOS模拟器模拟后台获取。是否可以模拟到期，以便它可以调用过期处理程序？我试过用一个无限循环并在模拟器上作为背景提取运行但似乎没有触发它。

task = UIApplication.SharedApplication.BeginBackgroundTask("bgEntityDownload", () =>
            {
                AppLogger.Instance.AddLog(AppLogLevel.Information,
                                      nameof(BgProcess),
                                      nameof(DownloadEntityFromServer),
                                      "Background Fetch Expired", "");
                App.CurrentDataStatus.HasSync = new EntityQueueBLL().HasData(siteId);
                UIApplication.SharedApplication.EndBackgroundTask(task);
                task = UIApplication.BackgroundTaskInvalid;
                System.Diagnostics.Debug.WriteLine("Ending .....");
                completionHandler?.Invoke(UIBackgroundFetchResult.NewData);
            });

Answer 1

以下是我的某个应用中的示例：

public async override void PerformFetch(UIApplication application, Action<UIBackgroundFetchResult> completionHandler)
{
    var result = UIBackgroundFetchResult.NoData;
    try
    {
        await Task.Run(async () =>
        {
            var iOSTaskId = UIApplication.SharedApplication.BeginBackgroundTask("MyBackgroundTask", ExpirationHandler);
            //result = await BackgroundFetchBoxOfficeTicketResults();
            await Task.Delay(60 * 1000);
            result = UIBackgroundFetchResult.NewData;
            UIApplication.SharedApplication.EndBackgroundTask(iOSTaskId);
        });
    }
    catch // Fetch Errors are Reported via analytics system within BackgroundFetchBoxOfficeTicketResults
    {
        result = UIBackgroundFetchResult.Failed;
    }
    completionHandler(result);
}

void ExpirationHandler()
{
    //Report(ProgID, PerFormFetchFailedID, DeviceID, $"User:{UserID}, Network:{NetworkType}");
    Console.WriteLine("beginBackgroundTaskWithName:expirationHandler: called...");
}

开始调试您的应用
将其放入背景
- 通过Home按钮，在物理设备上或在Sim上的硬件/家庭
在IDE中通过Run / Simulate iOS Background Fetch调用后台提取。

应该在大约30秒后调用过期处理程序。您有几秒来处理任何清理/日志记录。

Xamarin表单：iOS如何模拟后台提取过期

1 个答案: