单实例

singleTon.h

#pragma once
class SingleTon
{
public:
    
    ~SingleTon(void);
    static SingleTon* getInstance();

private:
    SingleTon(void);
    static SingleTon* Instance;

public:
    void SetNum(int num);
    void GetNum(void);
private:
    int Num;

};

SingleTon.cpp

#include <iostream>

#include "SingleTon.h"

SingleTon* SingleTon::Instance = NULL;//累指针初始化赋值

SingleTon::SingleTon(void)
{
    Num = 0;
}


SingleTon::~SingleTon(void)
{
    if(Instance != NULL)
    {
        delete Instance;
        Instance = NULL;
    }
   Num = 0;
}

SingleTon* SingleTon::getInstance()
{
    if(Instance == NULL)
    {
        Instance = new SingleTon;
    }
    return Instance;
}

void SingleTon::SetNum(int num)
{
    Num = num;
}

void SingleTon::GetNum()
{
    std::cout<<"Num = "<<Num<<std::endl;
}