带有 NSOperation 和 NSOperationQueue iOS 的后台任务

Question

我想上传一些即使应用程序进入后台也应该继续的文件。

目前我正在从数据库中检索文件，然后通过 NSOperation 将其添加到队列中，然后启动上传过程。

即使应用程序进入后台或前台，也应上传所有文件。 下面是单个任务的代码，任何人都可以给我一个提示，我们如何使它能够上传许多文件。

UIApplication* application = [UIApplication sharedApplication];
bgTask = [application beginBackgroundTaskWithExpirationHandler:^{
  // Clean up any unfinished task business by marking where you
  // stopped or ending the task outright.

  [application endBackgroundTask: bgTask];
  bgTask = UIBackgroundTaskInvalid;
}];

Answer 1

为什么不尝试这样做呢？ ..我还没有尝试过，我会在尝试后发布更新

UIApplication* application = [UIApplication sharedApplication];
bgTask = [application beginBackgroundTaskWithExpirationHandler:^{
  // Clean up any unfinished task business by marking where you
  // stopped or ending the task outright.

  // Bring up your NSOperation queue instance here and block this thread until it is complete
  [queue waitUntilAllOperationsAreFinished];

  [application endBackgroundTask: bgTask];
  bgTask = UIBackgroundTaskInvalid;
}]; 

还要确保您有办法在后台取消所有这些长期存在的操作

 bgTask = [application beginBackgroundTaskWithExpirationHandler:^{
        // Clean up any unfinished task business by marking where you.
        // stopped or ending the task outright.
        [queue cancelAllOperations];

        [application endBackgroundTask:endSessionTask];
        bgTask = UIBackgroundTaskInvalid;
    }];

Answer 2

如果您的应用遵循并满足必要条件，Apple 允许后台执行。 plese refer here