使用 AFNetworking 2.0 异常解析 JSON

Question

我在使用 AFNetworking 处理 JSON 解析数据时遇到问题。

这是我的代码：

        AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
        manager.responseSerializer = [AFHTTPResponseSerializer serializer];
        NSDictionary *parameters = @{@"strEmail": _logInEmail.text, @"strPassword":_logInPassword.text};
        [manager POST:@"http://carefid.com/api/user/login.php" parameters:parameters success:^

          (AFHTTPRequestOperation *operation, id responseObject) {


//NSString *string = [[NSString alloc] initWithData:responseObject encoding:NSUTF8StringEncoding];
              NSString *str = responseObject[@"error"];
            NSLog(@"JSON: %@", str);
            UIViewController *myController = [self.storyboard instantiateViewControllerWithIdentifier:@"rootController"];
            [self presentViewController:myController animated:YES completion:nil];

        } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
            NSLog(@"Error: %@", error);
        }];

当我尝试记录该值时，我收到此错误：

2014-07-15 14:39:08.438 carefid[7858:60b] -[_NSInlineData objectForKeyedSubscript:]: unrecognized selector sent to instance 0x1094c67a0
2014-07-15 14:39:08.441 carefid[7858:60b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[_NSInlineData objectForKeyedSubscript:]: unrecognized selector sent to instance 0x1094c67a0'
*** First throw call stack:
(
    0   CoreFoundation                      0x0000000101d48495 __exceptionPreprocess + 165
    1   libobjc.A.dylib                     0x00000001019c399e objc_exception_throw + 43
    2   CoreFoundation                      0x0000000101dd965d -[NSObject(NSObject) doesNotRecognizeSelector:] + 205
    3   CoreFoundation                      0x0000000101d39d8d ___forwarding___ + 973
    4   CoreFoundation                      0x0000000101d39938 _CF_forwarding_prep_0 + 120
    5   carefid                             0x000000010001f14f __34-[ViewController existingUserBtn:]_block_invoke + 95
    6   carefid                             0x0000000100015648 __64-[AFHTTPRequestOperation setCompletionBlockWithSuccess:failure:]_block_invoke46 + 40
    7   libdispatch.dylib                   0x0000000102669851 _dispatch_call_block_and_release + 12
    8   libdispatch.dylib                   0x000000010267c72d _dispatch_client_callout + 8
    9   libdispatch.dylib                   0x000000010266c3fc _dispatch_main_queue_callback_4CF + 354
    10  CoreFoundation                      0x0000000101da6289 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 9
    11  CoreFoundation                      0x0000000101cf3854 __CFRunLoopRun + 1764
    12  CoreFoundation                      0x0000000101cf2d83 CFRunLoopRunSpecific + 467
    13  GraphicsServices                    0x00000001040bef04 GSEventRunModal + 161
    14  UIKit                               0x0000000100570e33 UIApplicationMain + 1010
    15  carefid                             0x0000000100049183 main + 115
    16  libdyld.dylib                       0x00000001028cd5fd start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

什么可能导致这个问题？ responseObject 是字典吗？ 如果我的代码错误，我应该如何处理？

Answer 1

您将响应解析器设置为AFHTTPResponseSerializer 而不是AFJSONResponseSerializer。所以响应永远不会解析为 JSON。

所以改变

manager.responseSerializer = [AFHTTPResponseSerializer serializer];

到

manager.responseSerializer = [AFJSONResponseSerializer serializer];

正如您在评论中提到的，服务器正在传递内容text/html，如果可能，服务器应该说内容是操作类型application/json、text/json 或text/javascript。

如果无法更改服务器内容类型，您可以告诉AFJSONResponseSerializer 接受text/html，例如：

AFJSONResponseSerializer *jsonReponseSerializer = [AFJSONResponseSerializer serializer]; 
// This will make the AFJSONResponseSerializer accept any content type
jsonReponseSerializer.acceptableContentTypes = nil;
manager.responseSerializer = jsonReponseSerializer;