AFNetworking打印请求失败信息

http://blog.csdn.net/wzc10101415/article/details/51563699

NSError *underError = error.userInfo[@"NSUnderlyingError"];

        NSData *responseData = underError.userInfo[@"com.alamofire.serialization.response.error.data"];

        NSString *result = [[NSString alloc] initWithData:responseData  encoding:NSUTF8StringEncoding];

        NSLog(@"%@",result);