AFNetworking 2.5.0版本的使用

    // 基准baseURL
    NSURL *baseURL                         = [NSURL URLWithString:@"http://baidu.com/"];
    AFHTTPRequestOperationManager *manager = [[AFHTTPRequestOperationManager alloc] initWithBaseURL:baseURL];
    NSOperationQueue *operationQueue       = manager.operationQueue;
    [manager.reachabilityManager setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
        switch (status) {
            case AFNetworkReachabilityStatusReachableViaWWAN:
            case AFNetworkReachabilityStatusReachableViaWiFi:
                [operationQueue setSuspended:NO];
                
                // 此处可以发送有网络通知
                NSLog(@"有网络");
                
                break;
            case AFNetworkReachabilityStatusNotReachable:
            default:
                [operationQueue setSuspended:YES];
                
                // 此处可以发送断网通知
                NSLog(@"断网了");
                
                break;
        }
    }];
    
    // 开始监测网络
    [manager.reachabilityManager startMonitoring];

    // 初始化网址
    NSString *requestAddress =         @"http://api.openweathermap.org/data/2.5/forecast/daily?lat=39.88293652833437&lon=116.4621119300779&lang=zh_cn";
    
    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
    
    // 不带参数的GET请求
    [manager GET:requestAddress
      parameters:nil
         success:^(AFHTTPRequestOperation *operation, id responseObject) {
             NSLog(@"%@", responseObject);
    }
         failure:^(AFHTTPRequestOperation *operation, NSError *error) {
             NSLog(@"%@", error);
    }];