c – 错误“未在范围中声明”但带有接口

错误是

‘Entity’ was not declared in this scope

并指出：

protected:
    std::vector <Entity*> ent_map;

在IState.h中

我一直在努力解决它.一旦我在IState.h中做了一个前向声明,但是一旦我做了并尝试使用向量,它就会发出它是一个不完整的类,所以我回到原点.

有任何想法吗？

Entity.h

#ifdef __ENTITY__
#define __ENTITY__

#include <iostream>
#include <SDL.h>

class Entity
{
    public:
    virtual ~Entity();
    virtual void load(const char* fileName,std::string id,SDL_Renderer* pRenderer) = 0;
    virtual void draw() = 0;
    virtual void update() = 0 ;
    virtual void clean() = 0;

    /*void int getX() { return m_x;}
    void int getY() { return m_y;}
    void std::string getTexID {return textureID;}
    */


};


#endif // __ENTITY__

IState.h

#ifndef IState_
#define IState_

#include "Entity.h"
#include <vector>

class IState
{
    public :
    virtual ~IState();
    virtual void update() = 0;
    virtual void render(SDL_Renderer* renderTarget) = 0;
    virtual bool onEnter() = 0;
    virtual bool onExit() = 0;
    virtual void handleEvents(bool* gameLoop,SDL_Event event) = 0;
    virtual void resume() = 0;
    virtual std::string getStateID() = 0;
    virtual void setStateID(std::string id) = 0;

    protected:
        std::vector <Entity*> ent_map;

};


#endif // IState_