NSOperation和NSOperationQueue的后台任务iOS

Question

我想上传一些应该继续下去的文件，即使应用程序进入后台。

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

即使应用程序转到后台或前台，也应该上传所有文件。 下面是单个任务的代码，任何人都可以给我一个提示，我们如何使它可以上传许多文件。

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？ ..我还没有尝试过了，我会尝试此

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; 
}]; 

后发布的更新也保证你有办法取消在后台所有这些长期运行

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

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