标签：class com code img size http div string tar style width
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classA{public:voidprint(){cout<<"ThisisA"<<endl;}};classB:publicA{public:voidprint(){cout<<"ThisisB"<<endl;}};intmain(){//为了在以后便于区分，我这段main()代码叫做main1Aa;Bb;a.print();b.print();} |
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intmain(){//main2Aa;Bb;A*p1=&a;A*p2=&b;p1->print();p2->print();} |
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classA{public:virtualvoidprint(){cout<<"ThisisA"<<endl;}//现在成了虚函数了};classB:publicA{public:voidprint(){cout<<"ThisisB"<<endl;}//这里需要在前面加上关键字virtual吗？}; |
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classA{//虚函数示例代码public:virtualvoidfun(){cout<<1<<endl;}virtualvoidfun2(){cout<<2<<endl;}};classB:publicA{public:voidfun(){cout<<3<<endl;}voidfun2(){cout<<4<<endl;}}; |
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#include<iostream>usingnamespacestd;//将上面“虚函数示例代码”添加在这里intmain(){void(*fun)(A*);A*p=newB;longlVptrAddr;memcpy(&lVptrAddr,p,4);memcpy(&fun,reinterpret_cast<long*>(lVptrAddr),4);fun(p);deletep;system("pause");} |
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#include<iostream>usingnamespacestd;classA{//虚函数示例代码2public:virtualvoidfun(){cout<<"A::fun"<<endl;}virtualvoidfun2(){cout<<"A::fun2"<<endl;}};classB:publicA{public:voidfun(){cout<<"B::fun"<<endl;}voidfun2(){cout<<"B::fun2"<<endl;}};//end//虚函数示例代码2intmain(){void(A::*fun)();//定义一个函数指针A*p=newB;fun=&A::fun;(p->*fun)();fun=&A::fun2;(p->*fun)();deletep;system("pause");} |
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#include<iostream>usingnamespacestd;//将上面“虚函数示例代码2”添加在这里voidCallVirtualFun(void*pThis,intindex=0){void(*funptr)(void*);longlVptrAddr;memcpy(&lVptrAddr,pThis,4);memcpy(&funptr,reinterpret_cast<long*>(lVptrAddr)+index,4);funptr(pThis);//调用}intmain(){A*p=newB;CallVirtualFun(p);//调用虚函数p->fun()CallVirtualFun(p,1);//调用虚函数p->fun2()system("pause");} |
标签：class com code img size http div string tar style width
原文地址：http://www.cnblogs.com/duyy/p/3694685.html
