AFNetWorking同步请求

    dispatch_semaphore_t semaphore = dispatch_semaphore_create(0); //创建信号量
    AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
    manager.requestSerializer.timeoutInterval = 5;
    manager.completionQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
    //如果之前请求有值，则异步就好，不然会卡主线程
    if([OverallModel shareOverallModel].nSystemParameter){
        dispatch_semaphore_signal(semaphore);
    }
    [manager GET:[AppURLRequest getSystemVekey] parameters:nil progress:nil success:^(NSURLSessionDataTask * _Nonnull task, NSDictionary *responseObject) {
        
         dispatch_semaphore_signal(semaphore);//不管请求状态是什么，都得发送信号，否则会一直卡着进程
         NSInteger result = [[NSString stringWithFormat:@"%@",[responseObject objectForKey:@"result"]]integerValue];
        if(result == 1){
            NSString *nSystemParameter = NSZL(responseObject[@"data"][@"nSystemParameter"]);
            NSString *QQInfo = NSZL(responseObject[@"data"][@"QQInfo"]);
            [OverallModel shareOverallModel].nSystemParameter = nSystemParameter;
            [OverallModel shareOverallModel].QQInfo = QQInfo;
        }
    } failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
        dispatch_semaphore_signal(semaphore);//不管请求状态是什么，都得发送信号，否则会一直卡着进程
    }];
    
    dispatch_semaphore_wait(semaphore,DISPATCH_TIME_FOREVER);  //等待

 如果是在异步线程请求，则去掉 manager.completionQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);