Question

我想在应用处于后台时执行图形API调用。

我有一个方法可以执行以下操作（我将仅包含相关部分）：

- (void) facebookFetch
{
    NSString* query = @"<my_query">;
    NSDictionary *queryParam = @{ @"q": query };
    [FBSettings setLoggingBehavior:[NSSet setWithObjects:
                              FBLoggingBehaviorFBRequests,
                              nil]];
    // Make the API request that uses FQL
    [FBRequestConnection startWithGraphPath:@"/fql"
                           parameters:queryParam
                           HTTPMethod:@"GET"
                    completionHandler:^(FBRequestConnection *connection,
                                        id result,
                                        NSError *error) {
                      if (error) {
                        NSLog(@"Error: %@", [error localizedDescription]);
                      } else {
                        NSLog(@"Result: %@", result);
                      }
                    }];

}

我在这里的是，如果我在应用程序处于前台时调用此函数，我会收到回复。

现在问题是我需要在后台调用此函数，所以我已经实现了以下功能：

/** Background task **/
-(void)application:(UIApplication *)application performFetchWithCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler
{
    NSLog(@"####### background task!");

    if (![FBSession activeSession].isOpen) {
      NSLog(@"fbsession is NOT open!");
    } else {
      NSLog(@"fbsession is open!");
      [self facebookFetch];
    }

    completionHandler(UIBackgroundFetchResultNewData);

}

我得到了＃34; fbsession是开放的！＆＃34;消息，所以我正确输入相关代码，但后来我没有收到任何回复。

正如您所看到的，我记录了请求，以及我在中的：

URL: https://graph.facebook.com//fql?sdk=ios&access_token=ACCESS_TOKEN_REMOVED&q=<my_query>&migration_bundle=fbsdk%3A20131212&format=json Method: GET UserAgent: FBiOSSDK.3.13.1 MIME: multipart/form-data; boundary=3i2ndDfv2rTHiSisAbouNdArYfORhtTPEefj3q2f

但正如我之前告诉你的那样，在后台情况下，我没有收到回复。

任何帮助？

Answer 1

您需要在completionHandler(UIBackgroundFetchResultNewData);的完成模块中调用facebookFetch。

- (void) facebookFetch:(void (^)(UIBackgroundFetchResult))backgroundCompletion
{
    NSString* query = @"<my_query">;
    NSDictionary *queryParam = @{ @"q": query };
    [FBSettings setLoggingBehavior:[NSSet setWithObjects:
                              FBLoggingBehaviorFBRequests,
                              nil]];
    // Make the API request that uses FQL
    [FBRequestConnection startWithGraphPath:@"/fql"
                           parameters:queryParam
                           HTTPMethod:@"GET"
                    completionHandler:^(FBRequestConnection *connection,
                                        id result,
                                        NSError *error) {
                      if (error) {
                        NSLog(@"Error: %@", [error localizedDescription]);
                      } else {
                        NSLog(@"Result: %@", result);
                      }

                      if (backgroundCompletion) {
                          backgroundCompletion(UIBackgroundFetchResultNewData);
                      }
                    }];

}

/** Background task **/
-(void)application:(UIApplication *)application performFetchWithCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler
{
    NSLog(@"####### background task!");

    if (![FBSession activeSession].isOpen) {
      NSLog(@"fbsession is NOT open!");
    } else {
      NSLog(@"fbsession is open!");
      [self facebookFetch:completionHandler];
    }

}

您需要更新对facebookFetch:的任何其他来电，并且您可以传递NULL（或nil）。

facebook ios后台请求无声地失败

1 个答案: