error: expected class-name befor…

可能的原因有两个:

1.头文件的宏定义是一样的,多个文件的下面AA是一样的

#ifndef AA

#define AA

....

#endif 

 

2.继承的基类的头文件没有包含进来

错误的原因是,该类继承的那个基类的头文件没有包含进来, 

You can get the error

expected class-name before ‘{’ token

if you try to define a class as a subclass, and the superclassisn't defined in the local scope.

WRONG

class Foo: public Bar   // Foo is a subclass of Bar  

{    

// stuff  

};

RIGHT

#include "Bar.h"         // this makes Bar recognized  

class Foo: public Bar     

{    

// stuff  

};