如何通过指针深入理解多态实例的运用？

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C++// 使用指针实现多态实例详解// 1. 父类（DBConnector）// DBConnector.h#ifndef DBCONNECTOR_H#define DBCONNECTOR_H

class DBConnector {public: virtual void connect()=0; // 纯虚函数，实现连接数据库的逻辑 virtual ~DBConnector() {} // 虚析构函数，保证子类析构函数的调用};

#endif // DBCONNECTOR_H

C++ 通过指针实现多态实例详解

1.父类（DBConnector）

1）DBConnector.h

#include <string> using namespace std; class DBConnector { private: string name; public: DBConnector(); DBConnector(string _name); ~DBConnector(); void show(); };

2）DBConnector.cpp

#include "DBConnector.h" #include <iostream> using namespace std; DBConnector::DBConnector() { } DBConnector::DBConnector(string _name) { name = _name; } DBConnector::~DBConnector() { } void DBConnector::show() { cout << name << endl; }

2.子类1（MySqlConnector）

1）MSSqlConnector.h

#pragma once #include "DBConnector.h" class MSSqlConnector :public DBConnector { public: MSSqlConnector(); MSSqlConnector(string _name); ~MSSqlConnector(); };

2）MSSqlConnector.cpp

#include "MSSqlConnector.h" MSSqlConnector::MSSqlConnector() { } MSSqlConnector::MSSqlConnector(string _name) :DBConnector(_name) { } MSSqlConnector::~MSSqlConnector() { }

3.子类2（MSSqlConnector）

1）MSSqlConnector.h

#pragma once #include "DBConnector.h" class MSSqlConnector :public DBConnector { public: MSSqlConnector(); MSSqlConnector(string _name); ~MSSqlConnector(); };

2）MSSqlConnector.pp

#include "MSSqlConnector.h" MSSqlConnector::MSSqlConnector() { } MSSqlConnector::MSSqlConnector(string _name) :DBConnector(_name) { } MSSqlConnector::~MSSqlConnector() { }

4.Test

#include "MySqlConnector.h" #include "MSSqlConnector.h" #include <iostream> #include <string> using namespace std; void main() { MySqlConnector mysql("mysql"); MSSqlConnector mssql("mssql"); DBConnector* p; p = &mysql; p->show(); p = &mssql; p->show(); //mysql.show(); //mssql.show(); }

5.运行结果

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