C++中多态以及动态绑定

#include<iostream>
using namespace std;


class CFigure{
public:
double x, y;


public:
void SetDim(double i, double j = 0.0){
x = i;
y = j;
}




virtual void GetShowArea(){
cout << "无法计算面积" << endl;
}
};




class CTrangle :public CFigure{
public:
void GetShowArea(){
cout << "三角形：底边长" << x << "高：" << y << "面积：" << 0.5*x*y << endl;
}




};






class CRect : public CFigure{
void GetShowArea(){
cout << "矩形：长：" << x << "宽：" << y << "面积：" << x*y << endl; 
}


};


class CCircle :public CFigure{
public:
void GetShowArea(){
cout << "圆形：半径" << x << "面积：" << 3.15159 *x * x << endl;
}
};






int main(){
cout << "使用虚函数实现运行时多态" << endl;
CFigure *figure;
CTrangle triangle;
CRect rect;
CCircle circle;


figure = &triangle;


figure->SetDim(8.0, 5.0);
figure->GetShowArea();


figure = &rect;
figure->SetDim(10.0, 5.0);
figure->GetShowArea();


figure = &circle;
figure->SetDim(10.0);
figure->GetShowArea();


getchar();
getchar();
return 0;
}