NSOperation和NSOperationQueue的後臺任務iOS

Question

我想上傳一些應該繼續下去的文件，即使應用程序進入後臺。

目前我正在從數據庫中檢索文件，並通過NSOperation將其添加到隊列中，然後啓動上載過程。

即使應用程序轉到後臺或前臺，也應該上傳所有文件。 下面是單個任務的代碼，任何人都可以給我一個提示，我們如何使它可以上傳許多文件。

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

爲什麼不嘗試這樣做呢？ ..我還沒有嘗試過了，我會嘗試此

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; 
}]; 

後發佈的更新也保證你有辦法取消在後臺所有這些長期運行

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

如果您的應用遵從並滿足必要條件，Apple允許後臺執行。 plese refer here