iOS后台进程

Question

当我的应用程序正在运行时，我需要与服务器进行同步。 有时这种同步可能需要几分钟的时间。 在iPhone上，如果用户按主页按钮或设备自动锁定，则此任务会中断。

我想是这样的：

backgroundTaskID = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{ 
      [[UIApplication sharedApplication] endBackgroundTask:backgroundTaskID]; 
      backgroundTaskID = UIBackgroundTaskInvalid; 
    }]; 
[self Synchronization]; 

funcaosincronização：

-(void)Synchronization{ 

    object=nil; 

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ 
     [TheAppDelegate setSync:YES]; 

     send = NO; 
     responseObj = [[ConteinerInicial alloc] init]; 
     object = [self fillObjectContainer:1]; 

     error = NO; 

     [[objectManager HTTPClient] setDefaultHeader:@"Token" value:TheAppDelegate.token.token]; 
     [[objectManager HTTPClient] setDefaultHeader:@"Username" value:TheAppDelegate.token.userName]; 
     [[objectManager HTTPClient] setDefaultHeader:@"IDDevice" value:TheAppDelegate.token.IDDevice]; 

     [objectManager postObject:object path:@"" parameters:nil success:^(RKObjectRequestOperation *operation, RKMappingResult *result){ 
      NSArray *response = [result array]; 
      NSLog(@"Loading mapping result: %@", result); 

      NSDictionary *headerDictionary = [operation.HTTPRequestOperation.response allHeaderFields]; 
      NSString *authenticationStatus = [headerDictionary objectForKey:@"AuthenticationStatus"]; 

      // if server returns "NotAuthorized", user must login again 
      if ([authenticationStatus isEqualToString:@"NotAuthorized"]) { 
       [AppDelegate showErrorAlert:@"Login expired!"]; 
       [TheAppDelegate clearLoginToken]; 
       error = YES; 
       return; 
      } 

      responseObj = [response objectAtIndex:0]; 

      if(responseObj.Package.count>0) 
      { 
       [self savePackage:responseObj tipo:1]; 
       [self Synchronization]; 
      }else 
      { 
       [[UIApplication sharedApplication] endBackgroundTask:backgroundTaskID]; 
       backgroundTaskID = UIBackgroundTaskInvalid; 
      } 

     } failure: ^(RKObjectRequestOperation *operation, NSError *reportError){ 
      RKLogError(@"Operation failed with error: %@", reportError); 
      [AppDelegate showErrorAlert:@"There is some problem with the connection or the server! Please, check your connection or the address of the server and try again."]; 
      send = YES; 
      [TheAppDelegate setSync:NO]; 
      error = YES; 
     }]; 

    }); 
} 

而在同步结束准备：

[[UIApplication sharedApplication] endBackgroundTask:backgroundTaskID]; 
       backgroundTaskID = UIBackgroundTaskInvalid; 

但是这个代码不工作，任何人有一个想法我怎么能克服这个挑战？

同步的方式是询问数据直到不再存在。但是使用此代码，它只会在进入后台时收到的背景对象中结束

Answer 1

您的代码在过期处理程序中调用[self synchronization];。该块仅在您的应用程序用完后台运行时才被调用。所以你只有在没有时间去做的时候才会开始同步。

拨打电话[self synchronization];以外的区块。该块应包含清理/暂停代码，并结束后台任务...

另外，看看使用NSURLSession为好的iOS 7兼容性。