C++封装篇 (下)

对象数组

#include<iostream>
#include "Coordinate.h"

using namespace std;

int main() {
Coordinate coor[3];// 从栈上
coor[0].m_iX = 3;
coor[0].m_iY = 5;

Coordinate *p = new Coordinate[3];
p->m_iX = 7;
p[0].m_iY = 9;

p++;
p->m_iX = 11;
p[0].m_iY = 13;

p[1].m_iX = 15;
p++;
p->m_iY = 17;

for (int i = 0; i < 3; i++) {
cout << "coor_x " << coor[i].m_iX << endl;
cout << "coor_y " << coor[i].m_iY << endl;
}

for (int i = 0; i < 3; i++) {
cout << "p_x " << p->m_iX << endl;
cout << "p_y " << p->m_iY << endl;
p--;
}

p++;
delete []p;// []很重要，如果不是[]，就只会释放p[0]
p = NULL;

return 0;
}

对象成员

创建时，先创建对象成员，再穿件对象
销毁时，先销毁对象，在销毁对象成员(栈的数据结构)

深拷贝和浅拷贝

内存的拷贝，引用的拷贝
Array::Array(const Array &arr) {
cout << "Array &" << endl;
m_iCount = arr.m_iCount;
m_pArr = new int[m_iCount];
for (int i = 0; i < m_iCount; i++) {
m_pArr[i] = arr.m_pArr[i];
}
}

对象指针

对象成员指针

this指针

被隐藏了，默认的
代码区只有一份，成员变量有多份，通过this来区分不同的对象
返回对象时，要注意引用和非引用(临时对象)

常对象成员

常成员函数

void changX() const;// 相当于void changX(const Coordinate *this);

常指针与常引用

#include <iostream>
using namespace std;
class Coordinate {

public:
Coordinate(int x, int y):m_iX(x), m_iY(y) {
}
// 实现常成员函数
void printInfo() const {
cout << "(" << m_iX << "," << m_iY << ")" << endl;
}
public:
int m_iX;
int m_iY;
};

int main(void) {
const Coordinate coor(3, 5);

// 创建常指针p
const Coordinate *p = &coor;
// 创建常引用c
const Coordinate &c = coor;

coor.printInfo();
p->printInfo();
c.printInfo();

return 0;
}

结业小程序：走迷宫

介绍：一个小人走迷宫，左手或右手规则

类：Maze Person

代码:

Public.h // 常量定义

#pragma once

const int FAST = 1;
const int MIDD = 2;
const int SLOW = 3;

const char WALL = '*';
const char ROAD = ' ';

enum OBJECTIVE_DIRECTIONS {
UP, DOWN, LEFT, RIGHT
};

Maze.h

#pragma once

#include “Public.H”

#define MAX_HEIGHT 25

#define MAX_WIDTH 80

class Maze {
public:
Maze(char road, char wall);
Maze();
~Maze();

void setMap(char *map, int width, int height);
char* getMap();
int getWidth();
int getHeight();
bool isRoad(int x, int y);
void drawMap();

private:
char m_cRoad;
char m_cWall;
int m_iWidth;
int m_iHeight;
char m_cMap[MAX_WIDTH][MAX_HEIGHT];
};

Maze.cpp

#include “Maze.h”

#include

using namespace std;

Maze::Maze(char road, char wall) :m_cRoad(road), m_cWall(wall) {
}

Maze::Maze() {
}

Maze::~Maze() {
}

void Maze::setMap(char * map, int width, int height) {
for (int i = 0; i < height; i++) {
for (int j = 0; j < width; j++) {
m_cMap[i][j] = *map;
map++;
}
}
m_iHeight = height;
m_iWidth = width;
}

char* Maze::getMap() {
return &m_cMap[0][0];
}
int Maze::getWidth() {
return m_iWidth;
}
int Maze::getHeight() {
return m_iHeight;
}

bool Maze::isRoad(int x, int y) {
bool ret = false;
if (m_cMap[y][x] == ROAD || x == -1 || y == -1 || x == m_iWidth || y == m_iHeight) {
ret = true;
}
return ret;
}

void Maze::drawMap() {
for (int i = 0; i < m_iHeight; i++) {
for (int j = 0; j < m_iWidth; j++) {
cout << m_cMap[i][j];
}
cout << endl;
}
}

Person.h

#pragma once

#include “Public.h”

#include “Maze.h”

#include

using namespace std;

class Person {
public:
Person(int speed, int direction, int curX, int curY, char symbol);
~Person();

bool isOutOfMaze();
void goNextStep();
void start(Maze &maze);
void gotoxy(int x, int y);
void drawPerson();

private:
int m_iSpeed;
int m_iDirection;
int m_iCurX;
int m_iCurY;
int m_iPreX;
int m_iPreY;
char m_cSymbol;
Maze m_maze;
};

Person.cpp

#include “Person.h”

#include “cstdlib”

#include “windows.h”

Person::Person(int speed, int direction, int curX, int curY, char symbol):m_iSpeed(speed * 100),m_iDirection(direction),m_iCurX(curX),m_iCurY(curY),m_cSymbol(symbol) {

}

Person::~Person() {
}

bool Person::isOutOfMaze() {
bool ret = false;
if (m_iCurX == -1 || m_iCurY == -1 || m_iCurX == m_maze.getWidth() || m_iCurY == m_maze.getHeight()) {
ret = true;
}

return ret;
}
// 左手原则
void Person::goNextStep() {
m_iPreX = m_iCurX;
m_iPreY = m_iCurY;
switch (m_iDirection) {
case UP:
if (m_maze.isRoad(m_iCurX, m_iCurY - 1)) {
m_iCurY--;
if (m_maze.isRoad(m_iCurX, m_iCurY) && !isOutOfMaze()) {
m_iDirection = LEFT;
}
} else {
m_iDirection = RIGHT;
}
break;
case DOWN:
if (m_maze.isRoad(m_iCurX, m_iCurY + 1)) {
m_iCurY++;
if (m_maze.isRoad(m_iCurX, m_iCurY) && !isOutOfMaze()) {
m_iDirection = RIGHT;
}
} else {
m_iDirection = LEFT;
}
break;
case LEFT:
if (m_maze.isRoad(m_iCurX - 1, m_iCurY)) {
m_iCurX--;
if (m_maze.isRoad(m_iCurX, m_iCurY) && !isOutOfMaze()) {
m_iDirection = DOWN;
}
} else {
m_iDirection = UP;
}
break;
case RIGHT:
if (m_maze.isRoad(m_iCurX + 1, m_iCurY)) {
m_iCurX++;
if (m_maze.isRoad(m_iCurX, m_iCurY) && !isOutOfMaze()) {
m_iDirection = UP;
}
} else {
m_iDirection = DOWN;
}
break;
default:
break;
}
}

void Person::start(Maze &maze) {
m_maze = maze;
while (!isOutOfMaze()) {
drawPerson();
goNextStep();
}

gotoxy(0, m_maze.getHeight());
cout << "走出迷宫" << endl;
}

void Person::gotoxy(int x, int y) {// windows.h
COORD cd;
cd.X = x;
cd.Y = y;
SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE), cd);
}
void Person::drawPerson() {
gotoxy(m_iPreX, m_iPreY);
cout << ROAD;

gotoxy(m_iCurX, m_iCurY);
cout << m_cSymbol;
Sleep(m_iSpeed);
}