然后从JSON中获取值,然后存储到本地数据库。但是我的错误是:[__NSCFString objectForKey:]: unrecognized selector sent to instance 0xa6a2750和*** Terminatingapp due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFString objectForKey:]:[{"cat_id":&quo
我只是为测试目的编写以下代码:aStr = [aStr initWithFormatinitialization method -initWithFormat:locale:arguments: cannot be sent to an abstract object of class __NSCFString如果我编写以下代码,也会发生同样的事情
NSString *aStr = [
我有一个NSString类别类(NSString+URLEncoding.h)。我遇到了未知的选择器崩溃,因为我正在调用的字符串--类别方法--已经被iOS优化为一个iOS。-[__NSCFConstantString URLEncodedString]: unrecognized selector sent to instance 0x290174是否有人知道我如何使NSString类别包含常量字符串,甚