C2504'MainClass'：基类未定义

Question

我正在尝试实现状态设计模式，但我不断得到基类未定义的错误。这些是我的文件。 的 MainClass.h

#pragma once


#include "State1.h"
#include "State.h"

class State;
class MainClass
{
public:
    MainClass();
    ~MainCLass();
    void changeState(AuctionState* newState);
private:
    State *CurrentState;

};

在我的MainClass.cpp类中，changestate方法是

 void MainClass::changeState(State * newState)
    {
        delete CurrentState;
        CurrentState = newState;
    }

State.h

    #pragma once    

#include "MainClass.h"
class MainClass;
class AuctionState
{
public:
    virtual ~AuctionState();
    virtual void run(MainClass& context);
};

State1.h

#pragma once

#include "State2.h"
#include "State.h"
class State2;
class MainState :
    public AuctionState
{
public:
    MainState();
    ~MainState();
};

State1.cpp

#include "State1.h"



MainState::MainState()
{

}
void run(MainClass& context)
{

            //DO Stuff


            context.changeState(new State2);


}

MainState::~MainState()
{
}

所有其他状态文件以相同的方式实现