附加静态联编动态联编多态实例.doc

程序代码：(1)静态联编的例子试图显示派生类信息#include #include using namespace std; class CShape /基类 public: double Perimeter()return 0;/计算周长double Area()return 0; /计算面积; class CRectangle:public CShape /矩形private:double w,h; public: CRectangle(double x,double y)w=x;h=y;double Perimeter()return (w+h)*2;/同名覆盖double Area()return w*h; /同名覆盖; class CCircle:public CShape /圆private:double r; public: CCircle(double x)r=x; double Perimeter()return 3.1415926*r*2;/同名覆盖double Area()return 3.1415926*r*r; /同名覆盖; class CTriangle:public CShape /三角形private:double a,b,c; public: CTriangle(double x,double y,double z)a=x,b=y,c=z; double Perimeter()return a+b+c;/同名覆盖double Area()/计算圆的面积double p = ( a + b + c) / 2.0; return sqrt(p * ( p - a)*(p- b)*(p - c); /全局函数show()显示各种形状的周长和面积void show(CShape & s) cout 周长: s.Perimeter() endl;cout 面积: s.Area() endl;int main() CCircle cl(5.0);cout圆的信息：endl;show(cl);cout*endl;CRectangle rect(100,50);cout矩形的信息：endl;show(rect);cout*endl;CTriangle tri(3,4,5);cout三角形的信息：endl;show(tri);return 0; 程序运行结果:圆的信息：周长:0面积:0*矩形的信息：周长:0面积:0*三角形的信息：周长:0面积:0 (2)动态联编的例子(使用基类指针)#include #include using namespace std; class CShape /基类 public: virtual double Perimeter()return 0;/虚函数,计算周长virtual double Area()return 0; /虚函数,计算面积; class CRectangle:public CShape /矩形private:double w,h; public: CRectangle(double x,double y)w=x;h=y;double Perimeter()return (w+h)*2;/同名覆盖double Area()return w*h; /同名覆盖; class CCircle:public CShape /圆private:double r; public: CCircle(double x)r=x; double Perimeter()return 3.1415926*r*2;/同名覆盖double Area()return 3.1415926*r*r; /同名覆盖; class CTriangle:public CShape /三角形private:double a,b,c; public: CTriangle(double x,double y,double z)a=x,b=y,c=z; double Perimeter()return a+b+c;/同名覆盖double Area()/计算圆的面积double p = ( a + b + c) / 2.0; return sqrt(p * ( p - a)*(p- b)*(p - c); /全局函数show()显示各种形状的周长和面积void show(CShape * p) cout 周长: Perimeter() endl;cout 面积: Area() endl;int main() CCircle cl(5.0);cout圆的信息：endl;show(&cl);cout*endl;CRectangle rect(100,50);cout矩形的信息：endl;show(&rect);cout*endl;CTriangle tri(3,4,5);cout三角形的信息：endl;show(&tri);return 0; 程序运行结果:圆的信息：周长:31.4159面积:78.5398*矩形的信息：周长:300面积:5000*三角形的信息：周长:12面积:6(3)动态联编的例子改进(使用基类引用)#include #include using namespace std; class CShape /基类 public: virtual double Perimeter()return 0;/虚函数,计算周长virtual double Area()return 0; /虚函数,计算面积; class CRectangle:public CShape /矩形private:double w,h; public: CRectangle(double x,double y)w=x;h=y;double Perimeter()return (w+h)*2;/同名覆盖double Area()return w*h; /同名覆盖; class CCircle:public CShape /圆private:double r; public: CCircle(double x)r=x; double Perimeter()return 3.1415926*r*2;/同名覆盖double Area()return 3.1415926*r*r; /同名覆盖; class CTriangle:public CShape /三角形private:double a,b,c; public: CTriangle(double x,double y,double z)a=x,b=y,c=z; double Perimeter()return a+b+c;/同名覆盖double Area()/计算圆的面积double p = ( a + b + c) / 2.0; return sqrt(p * ( p - a)*(p- b)*(p - c); /全局函数show()显示各种形状的周长和面积void show(CShape & s) /全局函数的形参为基类引用cout 周长: s.Perimeter() endl;cout 面积: s.Area() endl;int main() CCircle cl(5.0);cout圆的信息：endl;show(cl);/函数的实参为派生类对象,下同cout*endl;CRectangle rect(100,50);cout矩形的信息：endl;show(rect);cout*endl;CTriangle tri(3,4,5);cout三角形的信息：Hurted( nPower); pWolf-FightBack( this); void Attack( CGhost * pGhost) /表现攻击动作的代码pGhost-Hurted( nPower); pGohst-FightBack( this); void Hurted ( int nPower) / 表现受伤动作的代码nLifeValue -= nPower; void FightBack( CWolf * pWolf) / 表现反击动作的代码pWolf -Hurted( nPower / 2); void FightBack( CGhost * pGhost) / 表现反击动作的代码pGhost-Hurted( nPower / 2 ); (5) 游戏魔法门之英雄无敌多态的实现方法(部分代码)/基类CCreature：class CCreature protected : int m_nLifeValue, m_nPower; public: virtual void Attack( CCreature * pCreature) virtual void Hurted( int nPower) virtual void FightBack( CCreature * pCreature) ; /派生类 CDragon: class CDragon : public CCreature public: virtual void Attack( CCreature * pCreature); virtual void Hurted( int nPower); virtual void FightBack( CCreature * pCreature); ; void CDragon:Attack(CCreature * p) /表现攻击动作的代码p-Hurted(m_nPower); /多态 p-FightBack(this); /多态 void CDragon:Hurted( int nPower) /表现受伤动作的代码m_nLifeValue -= nPower; void CDragon:FightBack(CCreature * p) /表现反击动作的代码p-Hurted(m_nPower/2); /多态 (6) 游戏魔法门之英雄无敌多态的实现方法(部分代码)#include #include #include using namespace std; class CShape public: virtual double Area() = 0; /纯虚函数virtual void PrintInfo() = 0; ; class CRectangle:public CShape public: int w,h; virtual double Area(); virtual void PrintInfo(); ; class CCircle:public CShape public: int r; virtual double Area(); virtual void PrintInfo(); ; class CTriangle:public CShape public: int a,b,c; virtual double Area(); virtual void PrintInfo(); ; double CRectangle:Area() return w * h; void CRectangle:PrintInfo() cout Rectangle: Area() endl; double CCircle:Area() return 3.14 * r * r ; void CCircle:PrintInfo() cout Circle: Area() endl; double CTriangle:Area() double p = ( a + b + c) / 2.0; return sqrt(p * ( p - a)*(p- b)*(p - c); void CTriangle:PrintInfo() cout Triangle: Area() n; for( i = 0;i c; switch(c) case R: pr = new CRectangle(); cin pr-w pr-h; pShapesi = pr; break; case C: pc = new CCircle(); cin pc-r; pShapesi = pc; break; case T: pt = new CTriangle(); cin pt-a pt-b pt-c; pShapesi = pt; break; qsort(pShapes,n,sizeof( CShape*),MyCompare); for( i = 0;i PrintInfo(); return 0; int MyCompare(const void * s1, const void * s2) double a1,a2; CShape * * p1 ; / s1,s2 是void * ，不可写“* s1”来取得s1指向的内容CShape * * p2; p1 = ( CShape * * ) s1; /s1,s