C++文件交互实践：职工管理系统

管理系统需求

实现一个基于多态的职工管理系统

创建管理类

管理类负责内容：

与用户的沟通菜单界面
对职工增删改查的操作
与文件的读写交互

文件交互 -- 写文件

void workerManger::save()
{
	ofstream ofs;
	ofs.open(FILENAME, ios::out);
	for (int i = 0; i < this->m_EmpNum; ++i)
	{
		ofs << this->m_EmpArray[i]->m_Id << " "
			<< this->m_EmpArray[i]->m_Name << " "
			<< this->m_EmpArray[i]->getDepNumber() << endl;
	}
	ofs.close();
}

文件交互 -- 读文件

第一次使用，文件未创建
文件存在，但是数据被用户清空
文件存在，并且保存职工的所有数据

在构造函数中初始化数据

workerManger::workerManger()
{
	ifstream ifs;
	ifs.open(FILENAME, ios::in);
	//1.文件不存在情况
	if (!ifs.is_open())
	{
		cout << "文件不存在" << endl;//测试输出
		//初始化人数
		this->m_EmpNum = 0;
		//初始化数组指针
		this->m_EmpArray = NULL;
		//初始化文件为空标志
		this->m_FileIsEmpty = true;
		ifs.close();//关闭文件对象
		return;
	}
	//2.文件存在但为空判断
	char ch;
	ifs >> ch;
	//如果ch为尾，那么读完后ifs.eof函数为空
	if (ifs.eof())
	{
		cout << "文件为空" << endl;//测试输出
		//初始化人数
		this->m_EmpNum = 0;
		//初始化数组指针
		this->m_EmpArray = NULL;
		//初始化文件为空标志
		this->m_FileIsEmpty = true;
		ifs.close();//关闭文件对象
		return;
	}
	//3.文件存在，并记录数据
    this->get_EmpNum();
}
//统计文件中人数
int workerManger::get_EmpNum()
{
	ifstream ifs;
	ifs.open(FILENAME, ios::in);
	int id;
	string name;
	int dId;
	int num = 0; 
	while (ifs >> id && ifs >> name && ifs >> dId)
	{
		//统计人数数量
		num++;
	}
    return num;
}

实现代码

职工管理系统.cpp

#include "workerManger.h"
#include"employee.h"
#include"manager.h"
#include"boss.h"
int main()
{
	workerManger wm;
	

	while (true)
	{
		wm.showMenu();
		cout << "请输入您的选择：" << endl;
		int	 num;
		cin >> num;
		switch (num)
		{
		case 0:
			wm.exitFunction();
			break;
		case 1:
			wm.AddEmp();
			break;
		case 2:
			wm.show_Emp();
			break;
		case 3:
			wm.del_Emp();
			break;
		case 4:
			wm.mod_Emp();
			break;
		case 5:
			wm.find_Emp();
			break;
		case 6:
			wm.sort_Emp();
			break;
		case 7:
			wm.clear_Emp();
			break;
		default:
			system("cls"); //清屏
			break;
		}
	}

	//Worker* worker = NULL;
	//worker = new employee(1, "张三", 1);
	//worker->showInfo();
	//delete worker;
	//worker = new manager(2, "李四", 2);
	//worker->showInfo();
	//delete worker;
	//worker = new boss(3, "王五", 23);
	//worker->showInfo();
	//delete worker;

}

workerManager.h

#pragma once
#include<iostream>
#include"employee.h"
#include"manager.h"
#include"boss.h"
#include<fstream>
#define FILENAME "empFile.txt"
using namespace std;
//管理类
class workerManger
{
public:
	workerManger();
	~workerManger();
	//菜单界面
	void showMenu();
	
	//退出功能
	void exitFunction();
	//添加职工功能
	void AddEmp();
	//写入文件功能
	void save();
	//统计文件中人数
	int get_EmpNum();
	//初始化员工
	void init_Emp();
	//显示员工
	void show_Emp();
	//删除员工
	//判断员工是否存在，如果存在返回职工所在数组中的位置，
	//不存在则返回-1
	int IsExit(int id);
	void del_Emp();
	//修改员工
	void mod_Emp();
	//查找员工
	void find_Emp();
	//员工排序
	void sort_Emp();
	//清空数据
	void clear_Emp();
	//记录文件中的人数个数
	int m_EmpNum;
	//员工数组的指针
	Worker** m_EmpArray;
	//标志文件是否为空
	bool m_FileIsEmpty;
	

};

workerManager.cpp

#include "workerManger.h"

void workerManger:: showMenu()
{
	cout << "***********************************" << endl;
	cout << "******** 欢迎使用职工管理系统！***********" << endl;
	cout << "******** 0. 退出管理程序  ***************" << endl;
	cout << "******** 1. 增加职工信息  ***************" << endl;
	cout << "******** 2. 显示职工信息****************" << endl;
	cout << "******** 3. 删除离职员工****************" << endl;
	cout << "******** 4. 修改员工信息****************" << endl;
	cout << "******** 5. 查找员工信息****************" << endl;
	cout << "******** 6. 按照编号排序****************" << endl;
	cout << "******** 7. 清空所有文档****************" << endl;
	cout << "***********************************" << endl;
}

void workerManger::exitFunction()
{
	system("pause");
	exit(0);
}
int workerManger::get_EmpNum()
{
	ifstream ifs;
	ifs.open(FILENAME, ios::in);
	int id;
	string name;
	int dId;
	int num = 0; 
	while (ifs >> id && ifs >> name && ifs >> dId)
	{
		//统计人数数量
		num++;
	}
	//关闭文件
	ifs.close();
	return num;
}
void workerManger::init_Emp()
{
	ifstream ifs;
	ifs.open(FILENAME, ios::in);
	int id;
	string name;
	int dId;
	int index = 0;
	while (ifs >> id && ifs >> name && ifs >> dId)
	{
		Worker* worker = NULL;
		//根据不同部门Id创建不同对象
		if (dId == 1)
		{
			worker = new employee(id, name, dId);
		}
		else if (dId == 2)
		{
			worker = new manager(id, name, dId);
		}
		else
		{
			worker = new boss(id, name, dId);
		}
		//存放在数据中
		this->m_EmpArray[index] = worker;
		index++;
	}
	//关闭文件
	ifs.close();

}
workerManger::workerManger()
{
	ifstream ifs;
	ifs.open(FILENAME, ios::in);
	//1.文件不存在情况
	if (!ifs.is_open())
	{
		//cout << "文件不存在" << endl;//测试输出
		//初始化人数
		this->m_EmpNum = 0;
		//初始化数组指针
		this->m_EmpArray = NULL;
		//初始化文件为空标志
		this->m_FileIsEmpty = true;
		ifs.close();//关闭文件对象
		return;
	}
	//2.文件存在但为空判断
	char ch;
	ifs >> ch;
	//如果ch为尾，那么读完后ifs.eof函数为空
	if (ifs.eof())
	{
		//cout << "文件为空" << endl;//测试输出
		//初始化人数
		this->m_EmpNum = 0;
		//初始化数组指针
		this->m_EmpArray = NULL;
		//初始化文件为空标志
		this->m_FileIsEmpty = true;
		ifs.close();//关闭文件对象
		return;
	}
	//3.文件存在，并记录数据
	int num = this->get_EmpNum();
	//cout << "职工人数为：" << num << endl;
	this->m_EmpNum = num;
	//开辟空间
	this->m_EmpArray = new Worker * [this->m_EmpNum];
	//将文件中的数据，存到数组中
	this->init_Emp();

}
void workerManger::save()
{
	ofstream ofs;
	ofs.open(FILENAME, ios::out);
	for (int i = 0; i < this->m_EmpNum; ++i)
	{
		ofs << this->m_EmpArray[i]->m_Id << " "
			<< this->m_EmpArray[i]->m_Name << " "
			<< this->m_EmpArray[i]->m_dId << endl;
	}
	ofs.close();
}
void workerManger:: AddEmp()
{
	cout << "请输入增加员工数量：" << endl;
	int addNum = 0;
	cin >> addNum;
	if (addNum > 0)
	{
		//计算新空间大小
		int newSize = this->m_EmpNum + addNum;
		//开辟新空间
		Worker** newSpace = new Worker * [newSize];
		int num = 0;
		if (this->m_EmpArray != NULL)
		{
			for (int i = 0; i < this->m_EmpNum; ++i)
			{
				newSpace[i] = this->m_EmpArray[i];
				num++;
			}
		}
		for (int i = 0; i < addNum; ++i)
		{
			int id;//职工编号
			string name;//职工名字
			int dId; //部门选择
			int preNum = this->m_EmpNum+i;
			cout << "请输入第" << i + 1 << "个职工的编号：" << endl;
			cin >> id;
			cout << "请输入第" << i + 1 << "个职工的名字：" << endl;
			cin >> name;
			cout << "请输入第" << i + 1 << "个职工的职位：" << endl;
			cout << "1.普通职工" << endl;
			cout << "2.经理" << endl;
			cout << "3.老板" << endl;

			cin >> dId;
			Worker* worker = NULL;
			switch (dId)
			{
			case 1:
				worker = new employee(id, name, dId);
				break;
			case 2:
				worker = new manager(id, name, dId);
				break;
			case 3:
				worker = new boss(id, name, dId);
				break;
			default:
				break;
			}
			//将创建职工职责，添加到数组中
			newSpace[this->m_EmpNum + i] = worker;
		}
		//释放原有空间
		delete[] this->m_EmpArray;
		//更改新空间的指向
		this->m_EmpArray = newSpace;
		//更新新的职工人数
		this->m_EmpNum = newSize;
		//更新职工不为空标志
		this->m_FileIsEmpty = false;
		//保存职工内容
		this->save();
		//提示添加成功
		cout << "成功添加" << addNum << "名新职工" << endl;
		//按任意键后，清屏回到上级目录	
		system("pause");
		system("cls");
	}
	else
	{
		cout << "输入有误" << endl;
	}

}
//显示员工
void workerManger::show_Emp()
{
	
	if (this->m_FileIsEmpty)
	{
		cout << "文件不存在或记录为空！" << endl;
	}
	else
	{
		for (int i = 0; i < m_EmpNum; ++i)
		{
			//利用多态调用接口
			this->m_EmpArray[i]->showInfo();
		}
	}
	system("pause");
	system("cls");
}

//删除员工
void workerManger::del_Emp()
{
	if (this->m_FileIsEmpty)
	{
		cout << "文件不存在或记录为空！" << endl;
	}
	else
	{
		//按照职工编号删除
		cout << "请输入想要删除的职工编号：" << endl;
		int id = 0;
		cin >> id;
		int index = this->IsExit(id);
		if (index != -1)//找到员工
		{
			for (int i = index; i < this->m_EmpNum-1; ++i)
			{
				this->m_EmpArray[i] = this->m_EmpArray[i + 1];
			}
			//更新数组中记录人员数
			this->m_EmpNum--;
			//更新文件
			this->save();
			cout << "删除成功！" << endl;
		}
		else
		{
			cout << "删除失败，没有该员工！" << endl;
		}
	}
	system("pause");
	system("cls");
}
int workerManger::IsExit(int id)
{
	int index = -1;
	for (int i = 0; i < this->m_EmpNum; ++i)
	{
		if (this->m_EmpArray[i]->m_Id == id)
		{
			index = i;
			break;
		}
	}
	return index;
}
//修改员工
void workerManger::mod_Emp()
{
	if (this->m_FileIsEmpty)
	{
		cout << "文件不存在或记录为空！" << endl;
	}
	else
	{
		cout << "请输入要修改职工的编号：" << endl;
		int id;
		cin >> id;
		int index = this->IsExit(id);
		if (index != -1)
		{
			delete this->m_EmpArray[index];
			int new_id;
			string new_name;
			int new_dId;
			cout << "查到："<<id<<"号员工，请输入新职工号：" << endl;
			cin >> new_id;
			cout << "请输入修改后职工的姓名：" << endl;
			cin >> new_name;
			cout << "请输入修改后职工的编号：" << endl;
			cout << "1.普通职工" << endl;
			cout << "2.经理" << endl;
			cout << "3.老板" << endl;
			cin >> new_dId;
			Worker* worker = NULL;
			switch (new_dId)
			{
			case 1:
				worker = new employee(new_id, new_name, new_dId);
				break;
			case 2:
				worker = new manager(new_id, new_name, new_dId);
				break;
			case 3:
				worker = new boss(new_id, new_name, new_dId);
				break;
			default:
				break;
			}
			m_EmpArray[index] = worker;
			this->save();
			cout << "修改成功！" << endl;
		}
		else
		{
			cout << "没有找到该员工！" << endl;
		}
	}
	system("pause");
	system("cls");
}
//查找员工
void workerManger::find_Emp()
{
	if (this->m_FileIsEmpty)
	{
		cout << "文件不存在或记录为空！" << endl;
	}
	else
	{
		cout << "请输入查找方式：" << endl;
		cout << "1. 按职工编号查找：" << endl;
		cout << "2. 按职工姓名查找：" << endl;
		int select = 0;
		cin >> select;
		if (select == 1)
		{
			cout << "请输入查找的职工编号：" << endl;
			int id;
			cin >> id;
			int f = this->IsExit(id);
			if (f != -1)
			{
				cout << "查找成功，编号为" << id << "的信息如下：" << endl;
				this->m_EmpArray[f]->showInfo();
			}
			else
			{
				cout << "没有该员工！" << endl;
			}
		}
		else if (select == 2)
		{
			cout << "请输入查找的职工姓名：" << endl;
			string name;
			cin >> name;
			bool flag = true;
			for (int i = 0; i < this->m_EmpNum; ++i)
			{
				if (this->m_EmpArray[i]->m_Name == name)
				{
					cout << "查找成功，姓名为" << name << "的信息如下：" << endl;
					this->m_EmpArray[i]->showInfo();
					flag = false;
				}
			}
			if (flag)
			{
				cout << "查无此人！" << endl;
			}
		}
		else
		{
			cout << "输入错误！" << endl;
		}
	}
	system("pause");
	system("cls");
}
//员工排序
void workerManger::sort_Emp()
{
	if (this->m_FileIsEmpty)
	{
		cout << "文件不存在或记录为空！" << endl;
		system("pause");
		system("cls");
	}
	else
	{
		cout << "请输入：1.升序排序" << endl;
		cout << "2.将序排序" << endl;
		int select;
		cin >> select;
		for (int i = 0; i < this->m_EmpNum; ++i)
		{
			int minOrmax = i; //声明最小值或最大值下标
			for (int j = i + 1; j < this->m_EmpNum; ++j)
			{
				if (select == 1)
				{
					if (this->m_EmpArray[j]->m_Id < this->m_EmpArray[minOrmax]->m_Id)
					{
						minOrmax = j;
					}
				}
				else
				{
					if (this->m_EmpArray[j]->m_Id > this->m_EmpArray[minOrmax]->m_Id)
					{
						minOrmax = j;
					}
				}
			}
			if (minOrmax != i)
			{
				Worker* temp = this->m_EmpArray[i];
				this->m_EmpArray[i] = this->m_EmpArray[minOrmax];
				this->m_EmpArray[minOrmax] = temp;
			
			}

		}
		cout << "排序成功！" << endl;
		this->save();
		this->show_Emp();
	}
}
//清空数据
void workerManger::clear_Emp()
{
	cout << "确定清空数据？" << endl;
	cout << "1. 确定" << endl;
	cout << "2. 退出" << endl;
	int select;
	cin >> select;
	if (select == 1)
	{
		ofstream ofs(FILENAME, ios::trunc);//删除文件后文件重新创建
		ofs.close();
		if (this->m_EmpArray != NULL)
		{
			//删除堆区的每个职工对象
			for (int i = 0; i < this->m_EmpNum; ++i)
			{
				delete this->m_EmpArray[i];
				this->m_EmpArray[i] = NULL;
			}
			//删除堆区数组指针
			delete[] this->m_EmpArray;
			this->m_EmpArray = NULL;
			this->m_FileIsEmpty = true;
		}
		cout << "清空成功！" << endl;
	}
	system("pause");
	system("cls");
}
workerManger:: ~workerManger()
{
	if (this->m_EmpArray != NULL)
	{
		delete[] this->m_EmpArray;
		this->m_EmpArray = NULL;
	}
}

worker.h

#pragma once
#include<iostream>
using namespace std;
class Worker
{
public:
	virtual void showInfo()=0;
	virtual string getDepNumber() = 0;
	int m_Id;
	string m_Name;
	int m_dId;

};

empolyee.h

#pragma once
#include"worker.h"
class employee: public Worker
{
public:
	employee(int id, string name, int dId);
	void showInfo();
	string getDepNumber();
};

empolyee.cpp

#include "employee.h"
employee::employee(int id, string name, int dId)
{
	this->m_Id = id;
	this->m_Name = name;
	this->m_dId = dId;
}
void employee::showInfo()
{
	cout << "职工编号：" << this->m_Id
		<< "\t职工姓名：" << this->m_Name
		<< "\t岗位：" << this->getDepNumber()
		<< "\t岗位职责：完成经理交给的任务" << endl;
}
string employee::getDepNumber()
{
	return string("员工");
}

manager.h

#pragma once
#include"worker.h"
class manager : public Worker
{
public:
	manager(int id, string name, int dId);
	void showInfo();
	string getDepNumber();
};

manager.cpp

#include "manager.h"
manager::manager(int id, string name, int dId)
{
	this->m_Id = id;
	this->m_Name = name;
	this->m_dId = dId;
}
void manager::showInfo()
{
	cout << "职工编号：" << this->m_Id
		<< "\t职工姓名：" << this->m_Name
		<< "\t岗位：" << this->getDepNumber()
		<< "\t岗位职责：完成老板交给的任务，并下发任务给员工" << endl;
}
string manager::getDepNumber()
{
	return string("经理");
}

boss.h

#pragma once
#include"worker.h"
class boss : public Worker
{
public:
	boss(int id, string name, int dId);
	void showInfo();
	string getDepNumber();
};

boss.cpp

#include "boss.h"
boss::boss(int id, string name, int dId)
{
	this->m_Id = id;
	this->m_Name = name;
	this->m_dId = dId;
}
void boss::showInfo()
{
	cout << "职工编号：" << this->m_Id
		<< "\t职工姓名：" << this->m_Name
		<< "\t岗位：" << this->getDepNumber()
		<< "\t岗位职责：管理公司所有事务" << endl;
}
string boss::getDepNumber()
{
	return string("老板");
}