一、继承访问权限测试

1.1实验内容

设计类A具有public, protected, private等不同属性的成员函数或变量；
类B通过public, protected, private等不同方式继承A，在类B的成员函数中测试访问A的成员函数或变量；
在类B中添加public, protected, private等不同属性的成员函数或变量，在外部测试访问B的各个成员函数或变量；
B以private方式继承A，尝试把A中的部分public成员提升为public。

1.2实现代码

#include<iostream>
using namespace std;
class A{
public:int a=0;protected:int b=0;private:int c=0;};class Pub_B: public A{
public:void show1( ){a=1;cout<<"Pub_B可以访问得到a="<<a<<endl;}void show2( ){b=1;cout<<"Pub_B可以访问得到b="<<b<<endl;}	/*	void show3( ){c=1;cout<<"Pub_B可以访问得到c="<<c<<endl;}不可访问*/int b1;protected:int b2;
private:int b3;
};class Pro_B: protected A{
public:void show1( ){a=2;cout<<"Pro_B可以访问得到a="<<a<<endl;}void show2( ){b=2;cout<<"Pro_B可以访问得到b="<<b<<endl;}	/*	void show3( ){    c=2;cout<<"Pro_B可以访问得到c="<<c<<endl;}不可访问*/int bb1;protected:int bb2;
private:int bb3;
};class Pri_B: private A{
public:void show1( ){a=8;cout<<"Pri_B可以访问得到a="<<a<<endl;}void show2( ){b=8;cout<<"Pri_B可以访问得到b="<<b<<endl;}	/*	void show3( ){     c=8;cout<<"Pri_B可以访问得到c="<<c<<endl;}不可访问*/using A::a;   //把a提升为public，可以被访问 int bbb1;protected:int bbb2;
private:int bbb3;
};class newPri_B: private Pri_B{
public:void show1( ){   // a被提升为public，可以被访问 a=28;cout<<"newPri_B可以访问得到a="<<a<<endl;}/*	void show2( ){b=28;cout<<"newPri_B可以访问得到b="<<b<<endl;  }不可访问 *//*	void show3( ){    c=28;cout<<"newPri_B可以访问得到c="<<c<<endl;} 不可访问 */protected:private:};int main()
{Pub_B aa;aa.show1();aa.show2();//外部访问Pub_B类的变量与成员函数，只有public的可以访问 aa.b1;//aa.b2   不可访问 //aa.b3    不可访问 //aa.show3();  不可访问 Pro_B bb;bb.show1();bb.show2();//bb.show3();  不可访问 Pri_B cc;cc.show1();cc.show2();//cc.show3();  不可访问 newPri_B dd;dd.show1();     // a被提升为public，可以被访问 //dd.show2();   不可访问 //dd.show3();  不可访问 return 0;
}

1.3运行结果

 

 二、友元类继承测试

2.1实验内容

设计类A含有私有变量a，在类A中友元给类C；
设计类B继承A，添加私有变量b；在类C中测试访问类B的成员变量a, b;
设计类D继承C，在D的成员函数中测试访问类A的成员变量a，类B的成员变量a, b。

2.2实现代码

#include<iostream>
using namespace std;
class A {
private:int a=1;
friend class C;
};class B: public A {
private:int b=2;
};class C {
public:int c=8;void show() {B bb;cout<<"类C可以访问得到a="<<bb.a<<endl;//cout<<"类C可以访问得到b="<<bb.b<<endl;  不可访问 }
};class D :public C {
public:void show() {cout<<"类D可以访问得到c="<<c<<endl; A a1;//cout<<"类D可以访问得到a="<<a1.a<<endl;  不可访问 B b1;//cout<<"类D可以访问得到a="<<b1.a<<endl;  不可访问 //cout<<"类D可以访问得到b="<<b1.b<<endl;  不可访问 }
};int main(){C cc;cc.show();D dd;dd.show();return 0;
}

2.3运行结果

 三、多态性综合运用

3.1实验内容

一般多态性函数：输入输出参数完全一样，在父类中添加virtual；
特殊多态性函数：输入或输出参数在子类中是父类的指针或基类的引用，在子类中对于的是子类的指针或子类的引用；
析构函数的多态性；
多继承，注意什么情况需要虚继承；

3.2一般性多态函数

新建CVehicle类，Move()是其内部虚函数，新建CCar类、CBicycle类、CMaglevTrain类继承CVehicle类，并重写其内部的函数Move()的实现方法以实现多态的效果。

3.2.1实现代码

#include <iostream>  
using namespace std;
class CVehicle
{
public:CVehicle() {m_nWheels = 8;}CVehicle(int nWheel) {m_nWheels = nWheel;}void Move() {cout << "Vehicle has many Wheels" << endl;};
protected:int m_nWheels;
};class CCar : virtual public CVehicle {
public:CCar() {m_nWheels = 4;}CCar(int nWheels) {m_nWheels = nWheels;}void Move() {cout << "Car has four Wheels" << endl;};
};class CBicycle :virtual public CVehicle {
public:CBicycle() {m_nWheels = 2;}CBicycle(int nWheels) {m_nWheels = nWheels;}void Move() {cout << "Bicycle has two Wheels" << endl;};
};class CMaglevTrain : public CCar, public CBicycle
{
public://无参构造函数CMaglevTrain() {m_nWheels = 0;}CMaglevTrain(int nWheels) {m_nWheels = nWheels;}void Move() {cout << "MaglevTrain has no Wheels" << endl;}
};void TestVehicle() {CVehicle* Vehicle[4];Vehicle[0] = new CVehicle;Vehicle[1] = new CCar;Vehicle[2] = new CBicycle;Vehicle[3] = new CMaglevTrain;for(int i = 0; i < 4; i++){Vehicle[i]->Move();}
}
int main()
{TestVehicle();return 0;
}

3.2.2运行结果

3.3特殊多态函数

为了让每个子类能够输出自己类中重写的函数Move,我们需要在每个子类的父类Move 函数前加上virtual。

3.3.1实现代码

void callMove(CVehicle* a) {a->Move();
}void TestVehicle()
{CVehicle vehicle;CCar car;CBicycle bicycle;CMaglevTrain maglev_train;callMove(&vehicle);callMove(&car);callMove(&bicycle);callMove(&maglev_train);
}

3.3.2运行结果

 3.4析构函数的多态性

设计矢量图，运用多继承设计组合图形，要求具备创建不同类型矢量图、选择图形、移动图形、用不同颜色显示图形（表示选中与否），用vector或数组管理图形。

3.4.1实现代码

 Main.cpp

#include<vector>
#include "graphics.h"
#include<iostream>
#include "CShape.h"
using namespace std;int main()
{//图形画布基础设置initgraph(640, 480);setbkcolor(WHITE);delay_ms(0);setcolor(BLACK);setfont(20, 0, "楷体");setbkmode(TRANSPARENT);//enter+左击-->新建矩形");//enter+右击-->新建三角形");//enter+滚轮中间-->新建组合图形//ctrl+左击-->复制图形");//ctrl+右击-->粘贴图形");vector<CShape*>shapes;vector<CShape*>shapestmp;shapes.push_back(new CTriangle(CPoint(320, 320), CPoint(250, 340), CPoint(340, 450)));//shapes.push_back(new CTriangle(CPoint(10, 10), CPoint(150, 10), CPoint(150, 150)));shapes.push_back(new CRect(CPoint(200, 200), CPoint(300, 300)));shapes.push_back(new Comgraphics(CRect(CPoint(250, 50))));//移动bool move_flag = false;bool copy_flag = false;bool redraw = true;//鼠标点击时记录它的坐标int clickX, clickY;int copyX, copyY;int checkedid = -1;int copyid = -1;for (; is_run(); delay_fps(60)) {while (mousemsg()) {mouse_msg msg = getmouse();//判断鼠标的移动if (msg.is_move()) {if (checkedid != -1) {if (move_flag) {shapes[checkedid]->Move(msg.x - clickX, msg.y - clickY);}}clickX = msg.x;clickY = msg.y;redraw = true;}// 判断鼠标左键else if (msg.is_left()) {// 判断鼠标左键是否按下if (msg.is_down()) {clickX = msg.x;clickY = msg.y;CPoint pt = CPoint(clickX, clickY);int isIn = 0;for (int i = 0; i < shapes.size(); i++) {if (shapes[i]->ptIn(pt)) {isIn = 1;//如果鼠标在图形区域内就设置移动的flag为truemove_flag = true;checkedid = i;redraw = true;break;}}if (isIn == 0)checkedid = -1;}else {move_flag = false;}}}// 重新绘图if (redraw) {redraw = false;cleardevice();for (int i = 0; i < shapes.size(); i++) {if (i == checkedid)shapes[i]->DrawColor();elseshapes[i]->Draw();}}while (kbmsg()) {key_msg msgk = getkey();if (msgk.key == key_enter && msgk.msg == key_msg_down) {mouse_msg msgm = getmouse();if (msgm.is_left()) {// 判断鼠标左键是否按下if (msgm.is_down()) {shapes.push_back(new CRect(CPoint(msgm.x, msgm.y)));redraw = true;}}if (msgm.is_right()) {// 判断鼠标右键是否按下if (msgm.is_down()) {shapes.push_back(new CTriangle(CPoint(msgm.x, msgm.y)));redraw = true;}}if (msgm.is_mid()) {CRect r1 = CRect(CPoint(msgm.x, msgm.y));// 判断鼠标中键是否按下if (msgm.is_down()) {shapes.push_back(new Comgraphics(r1));redraw = true;}}}if (msgk.key == key_control && msgk.msg == key_msg_down) {mouse_msg msgm = getmouse();if (msgm.is_left()) {// 判断鼠标左键是否按下if (msgm.is_down()) {copyX = msgm.x;copyY = msgm.y;CPoint pt = CPoint(copyX, copyY);for (int i = 0; i < shapes.size(); i++) {if (shapes[i]->ptIn(pt)) {//如果鼠标在图形区域内就设置移动的flag为truecopy_flag = true;copyid = i;break;}}}}if (msgm.is_right()) {// 判断鼠标右键是否按下if (msgm.is_down()) {if (copy_flag == true) {shapes.push_back(&(shapes[copyid]->Clone())->Move(msgm.x - copyX, msgm.y - copyY));redraw = true;}}}}}}closegraph();return 0;
}

CShape.h

#ifndef CSHAPE_H
#define CSHAPE_H
#include<string>
#include<math.h>
using namespace std;class CPoint;
class CRect;
class CShape
{
public:CShape();CShape(const CShape& shape);virtual ~CShape();virtual double GetArea() const;virtual bool ptIn(const CPoint& pt) const;virtual bool InRect(const CRect& rc) const;virtual void Draw() const;virtual void DrawColor();virtual CShape* Clone() const;virtual CShape& Move(int nOffsetX, int nOffsetY);protected:string m_sName;
};class CPoint :public CShape {
public:int m_nPosX;int m_nPosY;CPoint() {m_nPosX = 0;m_nPosY = 0;}CPoint(int nPosX, int nPosY);CPoint(const CPoint& pt);virtual ~CPoint();double GetArea() const;bool ptIn(const CPoint& pt) const;bool InRect(const CRect& rc) const;void Draw() const;void DrawColor();CPoint* Clone() const;CPoint& Move(int nOffsetX, int nOffsetY);
};
class CTriangle :virtual public CShape {
public:CTriangle() {}CTriangle(const CPoint& pt1, const CPoint& pt2, const CPoint& pt3);CTriangle(const CTriangle& rc);CTriangle(const CPoint& pt);virtual ~CTriangle();double GetArea() const;bool ptIn(const CPoint& pt) const;bool InRect(const CRect& rc) const;void Draw() const;void DrawColor();CShape* Clone() const;CShape& Move(int nOffsetX, int nOffsetY);CPoint m_pts[3];
};class CRect :virtual public CShape {
public:CRect() {}CRect(CPoint pt1, CPoint pt2);CRect(const CRect& rc);CRect(CPoint pt1);virtual ~CRect();double GetArea() const;bool ptIn(const CPoint& pt) const;bool InRect(const CRect& rc) const;void Draw() const;void DrawColor();CShape* Clone() const;CShape& Move(int nOffsetX, int nOffsetY);CPoint m_ptLT;CPoint m_ptBR;
};class Comgraphics :public CRect, public CTriangle {
public:Comgraphics(const CRect& pt1);Comgraphics(const Comgraphics& rc);Comgraphics(const CPoint pt1);virtual ~Comgraphics();double GetArea() const;bool ptIn(const CPoint& pt) const;bool InRect(const CRect& rc) const;void Draw() const;void DrawColor();CShape* Clone() const;CShape& Move(int nOffsetX, int nOffsetY);CPoint m_pt1;CPoint m_pt2;};
#endif

CShape.cpp

#include "CShape.h"
#include "graphics.h"
#include <iostream>
using namespace std;
//CShape
CShape::CShape()
{
}
CShape::CShape(const CShape& shape) {m_sName = shape.m_sName;
}
CShape::~CShape()
{
}
double CShape::GetArea() const {return 0;
}
bool CShape::ptIn(const CPoint& pt) const {return false;
}
bool CShape::InRect(const CRect& rc) const {return false;
}
void CShape::Draw() const
{
}
void CShape::DrawColor()
{
}
CShape* CShape::Clone() const {return new CShape(*this);
}
CShape& CShape::Move(int nOffsetX, int nOffsetY) {return *this;
}//CPoint
CPoint::CPoint(int nPosX, int nPosY) {m_nPosX = nPosX;m_nPosY = nPosY;
}
CPoint::CPoint(const CPoint& pt) {m_nPosX = pt.m_nPosX;m_nPosY = pt.m_nPosY;
}
CPoint::~CPoint() {//cout << "CPoint::~CPoint()\n";
}
double CPoint::GetArea() const {return 0;
}
bool CPoint::ptIn(const CPoint& pt) const {return false;
}
bool CPoint::InRect(const CRect& rc) const {return rc.ptIn(*this);
}
void CPoint::Draw() const {circle(m_nPosX, m_nPosY, 2);
}
void CPoint::DrawColor()
{
}
CPoint* CPoint::Clone() const {return new CPoint(*this);
}
CPoint& CPoint::Move(int nOffsetX, int nOffsetY) {m_nPosX += nOffsetX;m_nPosY += nOffsetY;return *this;
}//CTriangle
CTriangle::CTriangle(const CTriangle& tri) {for (int i = 0; i < 3; i++) {m_pts[i] = tri.m_pts[i];}
}
CTriangle::~CTriangle() {//cout << "CTriangle::~CTriangle()\n";
}
CTriangle::CTriangle(const CPoint& pt1, const CPoint& pt2, const CPoint& pt3) {m_pts[0] = pt1;m_pts[1] = pt2;m_pts[2] = pt3;
}
CTriangle::CTriangle(const CPoint& pt)
{CPoint* pt1 = new CPoint(pt.m_nPosX + 100, pt.m_nPosY + 90);CPoint* pt2 = new CPoint(pt.m_nPosX, pt.m_nPosY + 90);m_pts[0] = pt;m_pts[1] = *pt1;m_pts[2] = *pt2;
}CShape& CTriangle::Move(int nOffsetX, int nOffsetY) {for (int i = 0; i < 3; i++) {m_pts[i].Move(nOffsetX, nOffsetY);}return *this;
}
double CTriangle::GetArea() const {int x1, y1, x2, y2, x3, y3;x1 = m_pts[0].m_nPosX;y1 = m_pts[0].m_nPosY;x2 = m_pts[1].m_nPosX;y2 = m_pts[1].m_nPosY;x3 = m_pts[2].m_nPosX;y3 = m_pts[2].m_nPosY;double bottomLine = sqrt(pow(x1 - x2, 2) + pow(y1 - y2, 2));double verticalLine1 = abs((y1 - y2) * x3 - (x1 - x2) * y3 + (x1 - x2) * y2 - (y1 - y2) * x2);double verticalLine2 = sqrt(pow(y1 - y2, 2) + pow(x1 - x2, 2));double verticalLine = verticalLine1 / verticalLine2;return (verticalLine * bottomLine) / 2.0;
}
bool CTriangle::ptIn(const CPoint& pt) const {CTriangle c1 = CTriangle(m_pts[0], m_pts[1], pt);CTriangle c2 = CTriangle(m_pts[1], m_pts[2], pt);CTriangle c3 = CTriangle(m_pts[2], m_pts[0], pt);double totalArea = c1.GetArea() + c2.GetArea() + c3.GetArea();if (totalArea == this->GetArea())return true;elsereturn false;
}
bool CTriangle::InRect(const CRect& rc) const {return rc.ptIn(m_pts[0]) && rc.ptIn(m_pts[1]) && rc.ptIn(m_pts[2]);
}
void CTriangle::Draw() const {int poly[8] = { m_pts[0].m_nPosX ,m_pts[0].m_nPosY,m_pts[1].m_nPosX,m_pts[1].m_nPosY,m_pts[2].m_nPosX,m_pts[2].m_nPosY, m_pts[0].m_nPosX ,m_pts[0].m_nPosY };setfillcolor(EGERGB(0xFF, 0xFF, 0xFF));fillpoly(4, poly);
}
void CTriangle::DrawColor() {int poly[8] = { m_pts[0].m_nPosX ,m_pts[0].m_nPosY,m_pts[1].m_nPosX,m_pts[1].m_nPosY,m_pts[2].m_nPosX,m_pts[2].m_nPosY, m_pts[0].m_nPosX ,m_pts[0].m_nPosY };setfillcolor(EGERGB(0xFF, 0xA5, 0x00));fillpoly(4, poly);
}
CShape* CTriangle::Clone() const {return new CTriangle(*this);
}//CRect
CRect::CRect(CPoint pt1, CPoint pt2) {m_ptLT = CPoint(min(pt1.m_nPosX, pt2.m_nPosX), min(pt1.m_nPosY, pt2.m_nPosY));m_ptBR = CPoint(max(pt1.m_nPosX, pt2.m_nPosX), max(pt1.m_nPosY, pt2.m_nPosY));
}
CRect::CRect(const CRect& rc) {m_ptLT = rc.m_ptLT;m_ptBR = rc.m_ptBR;
}
CRect::CRect(CPoint pt1)
{m_ptLT = CPoint(pt1.m_nPosX, pt1.m_nPosY);m_ptBR = CPoint(pt1.m_nPosX + 100, pt1.m_nPosY + 100);
}
CRect::~CRect() {// cout << "CRect::CRect()\n";
}
double CRect::GetArea() const {return (m_ptBR.m_nPosX - m_ptLT.m_nPosX) * (m_ptBR.m_nPosY - m_ptLT.m_nPosY);
}
bool CRect::ptIn(const CPoint& pt) const {return (pt.m_nPosX >= m_ptLT.m_nPosX && pt.m_nPosX <= m_ptBR.m_nPosX) &&(pt.m_nPosY >= m_ptLT.m_nPosY && pt.m_nPosY <= m_ptBR.m_nPosY);
}
bool CRect::InRect(const CRect& rc) const {return rc.ptIn(m_ptLT) && rc.ptIn(m_ptBR);
}
void CRect::Draw() const {// 存储n个顶点的x,y坐标int pts[10] = { m_ptLT.m_nPosX,m_ptLT.m_nPosY,m_ptBR.m_nPosX,m_ptLT.m_nPosY,m_ptBR.m_nPosX,m_ptBR.m_nPosY,m_ptLT.m_nPosX,m_ptBR.m_nPosY,m_ptLT.m_nPosX,m_ptLT.m_nPosY };// 绘制n个顶点的多边形，第一个参数必须要传入n+1，pts最后一个顶点坐标和第一个相同//drawpoly(5, pts);setfillcolor(EGERGB(0xFF, 0xFF, 0xFF));fillpoly(5, pts);
}
void CRect::DrawColor() {int pts[10] = { m_ptLT.m_nPosX,m_ptLT.m_nPosY,m_ptBR.m_nPosX,m_ptLT.m_nPosY,m_ptBR.m_nPosX,m_ptBR.m_nPosY,m_ptLT.m_nPosX,m_ptBR.m_nPosY,m_ptLT.m_nPosX,m_ptLT.m_nPosY };// 绘制n个顶点的多边形，第一个参数必须要传入n+1，pts最后一个顶点坐标和第一个相同setfillcolor(EGERGB(0xFF, 0xA5, 0x00));fillpoly(5, pts);
}
CShape* CRect::Clone() const {return new CRect(*this);
}
CShape& CRect::Move(int nOffsetX, int nOffsetY) {m_ptLT.Move(nOffsetX, nOffsetY);m_ptBR.Move(nOffsetX, nOffsetY);return *this;}
//Comgraphics
Comgraphics::Comgraphics(const CRect&pt1){m_pt1.m_nPosX = pt1.m_ptBR.m_nPosX;m_pt1.m_nPosY = pt1.m_ptLT.m_nPosY + (pt1.m_ptBR.m_nPosY - pt1.m_ptLT.m_nPosY) / 2;m_pt2.m_nPosX = pt1.m_ptLT.m_nPosX + (pt1.m_ptBR.m_nPosX - pt1.m_ptLT.m_nPosX) / 2;m_pt2.m_nPosY = pt1.m_ptBR.m_nPosY;m_ptLT = pt1.m_ptLT;m_ptBR = pt1.m_ptBR;}
Comgraphics::Comgraphics(const Comgraphics& rc){m_pt1 = rc.m_pt1;m_pt2 = rc.m_pt2;m_ptBR = rc.m_ptBR;m_ptLT = rc.m_ptLT;
}
Comgraphics::Comgraphics(const CPoint pt1){m_ptLT = CPoint(pt1.m_nPosX, pt1.m_nPosY);m_ptBR = CPoint(pt1.m_nPosX + 60, pt1.m_nPosY + 80);
}
Comgraphics::~Comgraphics(){cout << "Comgraphics::~Comgraphics()" << endl;}
double Comgraphics::GetArea()  const{return 0.0;
}
bool Comgraphics::ptIn(const CPoint& pt) const {return (pt.m_nPosX >= m_ptLT.m_nPosX && pt.m_nPosX <= m_ptBR.m_nPosX) &&(pt.m_nPosY >= m_ptLT.m_nPosY && pt.m_nPosY <= m_ptBR.m_nPosY);
}
bool Comgraphics::InRect(const CRect& rc) const const {return rc.ptIn(m_ptLT) && rc.ptIn(m_ptBR);
}
void Comgraphics::Draw() const {// 存储n个顶点的x,y坐标int pts[10] = { m_ptLT.m_nPosX,m_ptLT.m_nPosY,m_ptBR.m_nPosX,m_ptLT.m_nPosY,m_ptBR.m_nPosX,m_ptBR.m_nPosY,m_ptLT.m_nPosX,m_ptBR.m_nPosY,m_ptLT.m_nPosX,m_ptLT.m_nPosY };// 绘制n个顶点的多边形，第一个参数必须要传入n+1，pts最后一个顶点坐标和第一个相同//drawpoly(5, pts);setfillcolor(GREEN);fillpoly(5, pts);line(m_pt1.m_nPosX, m_pt1.m_nPosY, m_pt2.m_nPosX, m_pt2.m_nPosY);line(m_ptLT.m_nPosX, m_ptLT.m_nPosY, m_pt2.m_nPosX, m_pt2.m_nPosY);line(m_pt1.m_nPosX, m_pt1.m_nPosY, m_ptLT.m_nPosX, m_ptLT.m_nPosY);
}
void Comgraphics::DrawColor() {// 存储n个顶点的x,y坐标int pts[10] = { m_ptLT.m_nPosX,m_ptLT.m_nPosY,m_ptBR.m_nPosX,m_ptLT.m_nPosY,m_ptBR.m_nPosX,m_ptBR.m_nPosY,m_ptLT.m_nPosX,m_ptBR.m_nPosY,m_ptLT.m_nPosX,m_ptLT.m_nPosY };// 绘制n个顶点的多边形，第一个参数必须要传入n+1，pts最后一个顶点坐标和第一个相同setfillcolor(YELLOW);fillpoly(5, pts);line(m_pt1.m_nPosX, m_pt1.m_nPosY, m_pt2.m_nPosX, m_pt2.m_nPosY);line(m_ptLT.m_nPosX, m_ptLT.m_nPosY, m_pt2.m_nPosX, m_pt2.m_nPosY);line(m_pt1.m_nPosX, m_pt1.m_nPosY, m_ptLT.m_nPosX, m_ptLT.m_nPosY);
}
CShape* Comgraphics::Clone() const {return new Comgraphics(*(this));
}CShape& Comgraphics::Move(int nOffsetX, int nOffsetY) {m_ptLT.Move(nOffsetX, nOffsetY);m_ptBR.Move(nOffsetX, nOffsetY);m_pt1.Move(nOffsetX, nOffsetY);m_pt2.Move(nOffsetX, nOffsetY);return *this;
}

3.4.2运行结果