将 AFN 错误 Error -> Data 转义为中文的方法

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

NSData *data=underError.userInfo[AFNetworkingOperationFailingURLResponseDataErrorKey];

NSString *str = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

NSLog(@"%@", str);