???????????????????????????AFNetworking??????????????????????????????????к?????????д????????????????????????????????????????????????????????????????????????
????-[NSNull length]: unrecognized selector sent to instance 0x30adb48
????????? ??????????????null????OC????NSNull?????????????????????????
???????????
???????????????ж????????????????????????????????
????//?ж???????
????if(![userNiceName isKindOfClass:[NSNull class]]){
????//??????
????[self.loglabBtnper setTitle:userNiceName forState:UIControlStateNormal];
????}