我正在使用AFNetworking库通过POST方法在服务器上发布数据。

以下是我的代码

- (void) callLoginAPI:(NSDictionary *)dictProfile{
    // 1
    NSDictionary *params = [NSDictionary dictionaryWithObjectsAndKeys:[dictProfile valueForKey:@"name"], @"username",
                                                                    [dictProfile valueForKey:@"first_name"],@"first_name",
                                                                    [dictProfile valueForKey:@"last_name"],@"last_name",
                                                                    [dictProfile valueForKey:@"email"],@"email",
                                                                    [dictProfile valueForKey:@"birthday"],@"dob",
                                                                    [dictProfile valueForKey:@"gender"],@"gender",
                                                                    [[dictProfile valueForKey:@"location"] valueForKey:@"name"],@"location",
                                                                    [dictProfile valueForKey:@"timezone"],@"timezone",
                                                                    @"",@"language",
                                                                    [NSString stringWithFormat:@"http://graph.facebook.com/%@/picture?type=large",[dictProfile valueForKey:@"id"]],@"profile_pic_url",
                                                                    @"",@"cover_pic_url",nil];



    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
    manager.requestSerializer = [AFJSONRequestSerializer serializer];



    [manager POST:@"http://10.1.81.35:8000/api/login/" parameters:params success:^(AFHTTPRequestOperation *operation, id responseObject) {
        NSLog(@"JSON: %@", responseObject);
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"Error: %@", error);
    }];
}

但是我得到以下错误响应

Error Domain=NSCocoaErrorDomain Code=3840 "The operation couldn’t be completed. (Cocoa error 3840.)" (JSON text did not start with array or object and option to allow fragments not set.) UserInfo=0x797f2620 {NSDebugDescription=JSON text did not start with array or object and option to allow fragments not set.}

我不明白代码有什么问题。