C++实现图书管理系统（Qt C++ GUI界面版）

前瞻
本项目基于【C++】图书管理系统(完整版)

注册：当用户点击注册时，将跳转到注册页面，程序会将用户信息存入txt文件中，注册成功后，会自动跳转到登录界面，用户也可以通过点击登录按钮跳转回登录界面

用户界面（学生或老师）：当用户登录成功后，进入操作界面，包括功能如下：
借书：

查看自己借阅情况

还书：

管理员界面： 包括功能如下：
增加书：

查看当前借阅情况：

查看所有图书：

查看借阅人详细信息：

目前该系统大致功能如上。

代码概览：

各个模块主要负责功能
主要用于数据处理、存储部分，类似后端
 CBook.h  用于对书抽象，并实现了>>的重载，便于文件读入，读出
 CUser.h  工具人，作为老师，学生的父类
 CStudent.h  对学生进行的抽象
 CTeacher.h 对老师进行的抽象
 CAdministrator.h 对管理的抽象
 CManagementBooks.h  用户所有的相关操作的中间执行者，有设计模式中代理的思想
 QtLibrarySystem.cpp  界面的的实现与系统入口
 主要用于数据暂时，处理用户输入，类似前端
 RegistrationPage.h 注册界面实现类
 UserPage.h用户界面实现类
 LoginPage.h登录界面实现类
 AdminPage.h管理员界面实现类

说明：获取方式见文章最后,点击查看，还有就是文件读入建议大家都直接放在相应项目里面，不然就写绝对路径。有问题欢迎大家在评论区提问，喜欢就点个赞咯！

全部代码与讲解:

CUser.cpp

#include "CUser.h"
#include<iostream>
#include<fstream>
using namespace std;




CUser::CUser()
{
    m_name = "陈1";
}

void CUser::setId(string id)
{
    m_id = id;
}

void CUser::setName(string name)
{
    m_name = name;
}

void CUser::setGender(string gender)
{
    m_gender = gender;
}



void CUser::setDepartment(string department)
{
    m_department = department;
}

void CUser::setPhone(string phone)
{
    m_phone = phone;
}




CUser::~CUser()
{
}

string CUser::returnBook(CManagementBooks& mb,string bookName)
{
    int all = mb.checkBorrowedBook(m_id);
    if (all == 0)
    {
        return  "您暂未借书,无需归还";
    }
    else
    {
        if (mb.checkTrueBorrow(m_id, bookName))
        {
            mb.Return(m_id, bookName);
            return "";
        }
        else
        {
            return "您并未借阅此书";
        }
    }
    return "";
}

string CUser::getId()
{
    return m_id;
}

string CUser::getName()
{
    return m_name;
}

string CUser::getGender()
{
    return m_gender;
}


string CUser::getDepartment()
{
    return m_department;
}

string CUser::getPhone()
{
    return m_phone;
}

std::ostream& operator<<(std::ostream& os, const CUser* user)
{
    os << endl << user->m_id << " " << user->m_name << " " << user->m_gender << " " << user->m_department << " " << user->m_phone;
    return os;
}

std::istream& operator>>(std::istream& is, CUser* user)
{
    is >> user->m_id >> user->m_name >> user->m_gender >> user->m_department >> user->m_phone;
    return is;
}

CTeacher.cpp

#include "CTeacher.h"
#include<fstream>

CTeacher::CTeacher()
{
    m_name = "刘一";
}

string CTeacher::borrowBookFromLibrary(CManagementBooks& mb, string name)
{

    int all = mb.checkBorrowedBook(m_id);
    if (all < 5)
    {
        if (mb.borrow(name))
        {
            ofstream writeFile("borrowedBook.txt", ios::app);
            mb.setMapValue(m_id, name);
            writeFile << endl << m_id << " " << name;
            writeFile.close();
        }
    }
    else
    {
        return "您已经超过了最大可借阅数";
    }
    return "";
}
void CTeacher::showInfo()
{
    cout << "姓名:" << m_name << " " << "学号:" << m_id << " " << "性别:" << m_gender << " " << "院系:" << m_department << " " << "联系方式:" << m_phone << endl;
}

CStudent.cpp

#include "CStudent.h"
#include<fstream>
using  namespace std;


CStudent::CStudent()
{
    m_class = "软件";
}

void CStudent::showInfo()
{
    cout << "姓名:" << m_name << " " << "学号:" << m_id << " " << "性别:" << m_gender << " " << "院系:" << m_department << " " << "班级:" << m_class << " " << "联系方式:" << m_phone << endl;
}

string CStudent::borrowBookFromLibrary(CManagementBooks& mb, string name)
{
    int all = mb.checkBorrowedBook(m_id);
    if (all < 3)
    {
        if (mb.borrow(name))
        {
            ofstream writeFile("borrowedBook.txt", ios::app);
            mb.setMapValue(m_id, name);
            writeFile << endl << m_id << " " << name;
            writeFile.close();
        }
        else
        {
            return "此书数量不足或暂无此书";
        }
    }
    else
    {
        return "您已经超过了最大可借阅数";
    }
    return "";

}



void CStudent::setClass(string Class)
{
    m_class = Class;
}



string CStudent::getClass()
{
    return m_class;
}

CManagementBooks.cpp

#include "CManagementBooks.h"
#include<algorithm>
using namespace std;
static bool cmp(CBook book1, CBook book2)
{
	return book1.getNum() > book2.getNum();
}
void CManagementBooks::showCurrentAllBook()
{
	sort(m_books.begin(), m_books.end(), cmp);
	for (int i = 0; i < m_allBookNum; i++)
	{
		cout << "书名:" << m_books[i].getName() << " " << "剩余数量" << m_books[i].getNum() << endl;
	}
}

CManagementBooks::CManagementBooks()
{
	m_allBookNum = 0;
}

void CManagementBooks::addBook(CBook book)
{
	int flag = 0;
	for (int i = 0; i < m_allBookNum; i++)
	{
		if (m_books[i].getName() == book.getName())
		{
			flag = 1;
			m_books[i].setNum(m_books[i].getNum() + book.getNum());
			ofstream writeFile("library.txt", ios::out);
			for (int i = 0; i < m_allBookNum; i++)
			{
				writeFile << m_books[i];
			}
			writeFile.close();
			break;
		}
	}
	if (!flag)
	{
		ofstream writeFile("library.txt", ios::app);
		m_books.push_back(book);
		m_allBookNum++;
		writeFile << book;
		writeFile.close();
	}
}



int CManagementBooks::getAllBookNum()
{
	return m_allBookNum;
}

void CManagementBooks::showAllBooksInfo()
{
	sort(m_books.begin(), m_books.end(), cmp);
	for (int i = 0; i < m_allBookNum; i++)
	{
		m_books[i].showInfo();
	}
}

bool CManagementBooks::borrow(string name)
{

	for (int i = 0; i < m_allBookNum; i++)
	{
		if (m_books[i].getName() == name)
		{
			if (m_books[i].getNum() >= 1)
			{
				m_books[i].setNum(m_books[i].getNum() - 1);
				ofstream writeFile("library.txt");
				for (int i = 0; i < m_allBookNum; i++)
				{
					writeFile << m_books[i];
				}
				writeFile.close();
				return true;
			}
			else
			{
				return false;
			}
		}

	}
	return false;
}

void CManagementBooks::Return(string id, string bookName)
{
	CBook book;
	book.setName(bookName);
	addBook(book);
	ofstream writeFile("borrowedBook.txt", ios::out);
	for (auto iter = m_outBookMap.begin(); iter != m_outBookMap.end(); ++iter)
	{
		if (iter->first == id && iter->second == bookName)
		{
			m_outBookMap.erase(iter);
			break;
		}
	}
	for (auto map : m_outBookMap)
	{
		writeFile << endl << map.first << " " << map.second;
	}
	writeFile.close();
}

void CManagementBooks::initOutBook()
{
	ifstream readFile("borrowedBook.txt");
	if (!readFile.is_open())
	{
		cout << "查看全体借书情况数据读取出错" << endl;
	}
	else
	{
		while (!readFile.eof())
		{
			string studentId, bookName;
			readFile >> studentId >> bookName;
			m_outBookMap.insert(pair<string, string>(studentId, bookName));
		}
	}
	readFile.close();

}

void CManagementBooks::checekOutBook()
{
	for (auto map : m_outBookMap)
	{
		cout << "借阅人学工号:" << map.first << " " << "借阅书名:" << map.second << endl;
	}
}

void CManagementBooks::initBooks()
{
	ifstream readFile;
	readFile.open("library.txt");
	if (!readFile.is_open())
	{
		cout << "图书数据读取错误" << endl;
		readFile.close();
		return;
	}
	while (!readFile.eof())
	{

		CBook book;
		readFile >> book;
		m_allBookNum++;
		m_books.push_back(book);
	}
	readFile.close();
}

int CManagementBooks::checkBorrowedBook(string userId)
{

	int flag = 0;
	for (auto map : m_outBookMap)
	{
		if (userId == map.first)
		{
			if (!flag)
			{
				cout << "您已经借的全部图书如下：" << endl;
				flag++;
			}
			else
			{
				flag++;
			}
			cout << map.second << " ";
		}
	}
	if (!flag)
	{
		cout << "您目前没有借书" << endl;
	}
	cout << "共：" << flag << "本";
	cout << endl;
	return flag;
}

vector<userInfo> CManagementBooks::viewBorrowerDetails()
{
	ifstream readFile("teacher.txt");
	ifstream readFile1("student.txt");
	vector<userInfo>users;
	if (!readFile1.is_open() || !readFile.is_open())
	{
		cout << "用户数据读取错误" << endl;
	}
	while (!readFile1.eof())
	{
		string act1, name, department, gender,phone;
		readFile1 >> act1 >> name >> gender >> department>> phone;
		if(act1!="" && name != "")
		users.push_back({ act1,name ,gender ,department,"学生",phone});
	}
	while (!readFile.eof())
	{
		string act1, name, department, gender, phone;
		readFile >> act1 >> name >> gender >> department;
		if (act1 != "" && name != "")
		users.push_back({ act1,name ,gender ,department,"老师",phone });

	}
	readFile.close();
	readFile1.close();
	return users;
}

bool CManagementBooks::checkTrueBorrow(string id, string bookName)
{

	for (auto map : m_outBookMap)
	{
		if (map.first == id && map.second == bookName)
		{
			return true;
		}
	}
	return false;
}

void CManagementBooks::setMapValue(string userId, string bookName)
{
	m_outBookMap.insert(pair<string, string>(userId, bookName));
}

vector<CBook> CManagementBooks::getAllBook()
{
	return m_books;
}

unordered_multimap<string, string> CManagementBooks::getOutBookMap()
{
	return m_outBookMap;
}

CBook.cpp

#include "CBook.h"
#include <iostream>
#include<fstream>
using namespace std;


CBook::CBook()
{
	string b = "";
	string randStr = "0123456789X";
	for (int i = 0; i <= 12; i++)
	{
		if (i == 1 || i == 5 || i == 11)
		{
			b += '-';
		}
		else
		{
			if (i == 12)
			{
				b += randStr[rand() % 11];
			}
			else
			{
				b += randStr[rand() % 10];
			}
		}
	}
	m_num = 1;
	m_name = "等待戈多";
	m_author = "xx元";
	m_isbn = b;
	m_page = rand();
	m_pressInfo = "xx出版社";
	m_price = rand();
}

void CBook::setNum(int num)
{
	m_num = num;
}

int CBook::getNum()
{
	return m_num;
}


void CBook::setName(string name)
{
	m_name = name;
}

string CBook::getName()
{
	return m_name;
}

void CBook::setIsbn(string isbn)
{
	m_isbn = isbn;
}

string CBook::getIsbn()
{
	return m_isbn;
}

void CBook::setPressInfo(string perssInfo)
{
	m_pressInfo = perssInfo;
}

string CBook::getPressInfo()
{
	return m_pressInfo;
}

void CBook::setPrice(double price)
{
	m_price = price;
}

double CBook::getPrice()
{
	return m_price;
}

void CBook::setPage(int page)
{
	m_page = page;

}

int CBook::getPage()
{
	return m_page;
}

void CBook::setAuthor(string author)
{
	m_author = author;
}

string CBook::getAuthor()
{
	return m_author;
}


void CBook::checkIsnb()
{
	int sum = 0;
	for (int i = 0, j = 1; i < m_isbn.size(); i++) {
		if (m_isbn[i] != '-' && i != 12) {
			sum += (m_isbn[i] - '0') * j;
			j++;
		}

	}
	sum %= 11;
	char c = 'X';
	if (sum < 10) c = sum + '0';
	if (m_isbn[12] == c) puts("This book isbn are Right!");
	else puts("This book isbn are wrong!");
}



bool CBook::isBorrowed()
{
	if (m_num >= 1)
	{
		m_num--;
		return true;
	}
	return false;
}

void CBook::showInfo()
{
	cout << "作者:" << m_author << " " << "isbn号码:" << m_isbn << " " << "书本名称:" << m_name << " "
		<< "总页数:" << m_page << " " << "出版社:" << m_pressInfo << " " << "价格:" << m_price
		<< " " << "剩余本数:" << m_num << endl;
}

std::ostream& operator <<(std::ostream& os, const CBook& book)
{
	os << endl << book.m_name << " " << book.m_isbn << " " << book.m_pressInfo << " " << book.m_price << " " << book.m_page << " " << book.m_author << " " << book.m_num;
	return os;
}

std::istream& operator>>(std::istream& is, CBook& book)
{
	is >> book.m_name >> book.m_isbn >> book.m_pressInfo >> book.m_price >> book.m_page >> book.m_author >> book.m_num;
	return is;
}

}

userPage.cpp

#include "UserPage.h"
#include <QMessageBox>
#include <QFont>

UserPage::UserPage(QWidget* parent) : QWidget(parent)
{
    // 创建主布局
    QVBoxLayout* mainLayout = new QVBoxLayout(this);
    setWidgetFont(this);

    // 创建选项卡部件
    tabWidget = new QTabWidget(this);

    // 借书选项卡
   
    // 创建显示当前图书列表的QTableWidget
    QTableWidget* currentBooksList = new QTableWidget(borrowTab);
    currentBooksList->setObjectName("currentBooksList");
    setWidgetFont(currentBooksList);
    // 创建标签用于说明图书列表
    QLabel* currentBooksLabel = createStyledLabel("当前图书列表：");
    borrowLayout->addWidget(currentBooksLabel);
    borrowLayout->addWidget(currentBooksList);
    // 添加书名输入标签和输入框
    QLabel* bookNameLabel = createStyledLabel("输入要借的书名：");
    borrowLayout->addWidget(bookNameLabel);
    borrowLayout->addWidget(bookNameEdit);
    borrowLayout->addWidget(borrowButton);
    tabWidget->addTab(borrowTab, "借书");

    // 查看借书情况选项卡
    

    // 还书选项卡
    

    mainLayout->addWidget(tabWidget);
    // 设置编码
    codec = QTextCodec::codecForName("GBK");

    // 连接借书按钮点击事件
    connect(borrowButton, &QPushButton::clicked, this, &UserPage::onBorrowButtonClicked);
    // 连接还书按钮点击事件
    connect(returnButton, &QPushButton::clicked, this, &UserPage::onReturnButtonClicked);
    connect(tabWidget, &QTabWidget::currentChanged, [this](int index) {
        if (index == tabWidget->indexOf(borrowedBooksTab)) {
            onViewBorrowedBooksClicked();
        }
        else if (index == tabWidget->indexOf(returnTab)) {
            onShowBorrowedBooksForReturnClicked();
        }
        else if (index == tabWidget->indexOf(borrowTab)) {
            onBorrowTabClicked();
        }
        });
    mb.initBooks();
    mb.initOutBook();
    initCurrentBookList();
}

void UserPage::onBorrowButtonClicked()
{
    QString bookName = bookNameEdit->text();
    if (bookName.isEmpty())
    {
        QMessageBox::warning(this,"借书提示","请输入要借的书名");
        return;
    }
    std::string allow = user->borrowBookFromLibrary(mb, codec->fromUnicode(bookName).toStdString());
    if (allow != "")
    {
        QMessageBox::critical(this, "借书失败", codec->toUnicode(allow.c_str()));
        return;
    }
    // 尝试获取当前图书列表部件
    QTableWidget* currentBooksList = this->findChild<QTableWidget*>("currentBooksList");
    if (currentBooksList)
    {
        QList<QTableWidgetItem*> foundItems = currentBooksList->findItems(bookName, Qt::MatchExactly);
        if (!foundItems.isEmpty())
        {
            QTableWidgetItem* itemToModify = foundItems.first();
            int row = currentBooksList->row(itemToModify);

            // 获取当前可借数量并减1
            QTableWidgetItem* numItem = currentBooksList->item(row, 6);
            int currentNum = numItem->text().toInt();
            if (currentNum > 0)
            {
                currentNum--;
                numItem->text() = QString::number(currentNum);
                QMessageBox::information(this, "借书成功", "已成功借阅 " + bookName);
                // 重新加载图书数据
                onBorrowTabClicked();
            }
        }
    }
}

void UserPage::onReturnButtonClicked()
{
    QList<QTableWidgetItem*> selectedItems = returnableBooksList->selectedItems();
    if (selectedItems.isEmpty())
    {
        QMessageBox::warning(this, "还书提示", "请选择要归还的书籍");
        return;
    }

    // 使用QSet来避免重复添加书籍ID
    QSet<QString> addedBookIds;
    QList<QString> bookIds;
    for (QTableWidgetItem* item : selectedItems)
    {
        // 获取该项所在行的索引
        int row = returnableBooksList->row(item);
        // 获取该行第二列的表格项（索引为1）
        QTableWidgetItem* secondColumnItem = returnableBooksList->item(row, 1);
        if (secondColumnItem)
        {
            QString bookId = secondColumnItem->text();
            if (!addedBookIds.contains(bookId))
            {
                bookIds.append(bookId);
                addedBookIds.insert(bookId);
            }
        }
    }

    // 执行还书操作，假设user有还书相关函数，mb是管理书籍相关数据的对象
    std::string result;
    for (const QString& bookId : bookIds)
    {
        // 这里调用还书函数，根据实际情况可能需要调整参数传递方式
        result = user->returnBook(mb, codec->fromUnicode(bookId).toStdString());
        if (result != "")
        {
            break;
        }
    }
    if (result == "")
    {
        // 还书成功，更新界面显示
        QMessageBox::information(this, "还书成功", "已成功归还所选书籍");

        // 重新加载当前用户借阅的书籍列表，以更新界面显示
        onShowBorrowedBooksForReturnClicked();
    }
    else
    {
        QMessageBox::warning(this, "还书失败", codec->toUnicode(result.c_str()));
    }
}

QLabel* UserPage::createStyledLabel(const QString& text)
{
    QLabel* label = new QLabel(text);
    setWidgetFont(label);
    return label;
}

void UserPage::setWidgetFont(QWidget* widget)
{
    QFont font;
    font.setFamily("宋体");
    font.setPointSize(16);
    widget->setFont(font);
}

void UserPage::initCurrentBookList()
{
    // 清空之前的显示内容
   
    QTableWidget* currentBooksList = this->findChild<QTableWidget*>("currentBooksList");
    currentBooksList->setEditTriggers(QAbstractItemView::NoEditTriggers);
    if (currentBooksList)
    {
        // 设置表格列数和表头
        currentBooksList->setColumnCount(7);
        QStringList headers;
        headers << "作者" << "isbn号码" << "书本名称" << "总页数" << "出版社" << "价格" << "剩余本数";
        currentBooksList->setHorizontalHeaderLabels(headers);

        // 设置表格字体大小
        QFont tableFont;
        tableFont.setPointSize(10); // 设置字体大小为12，你可以根据需要调整这个值
        currentBooksList->setFont(tableFont);

        // 设置表头字体大小
        QHeaderView* headerView = currentBooksList->horizontalHeader();
        QFont headerFont;
        headerFont.setPointSize(10); // 设置字体大小为12，你可以根据需要调整这个值
        headerView->setFont(headerFont);

        // 添加书籍信息
        for (auto& book : mb.getAllBook())
        {
            int row = currentBooksList->rowCount();
            currentBooksList->insertRow(row);
            QTableWidgetItem* authorItem = new QTableWidgetItem(codec->toUnicode(book.getAuthor().c_str()));
            QTableWidgetItem* isbnItem = new QTableWidgetItem(codec->toUnicode(book.getIsbn().c_str()));
            QTableWidgetItem* nameItem = new QTableWidgetItem(codec->toUnicode(book.getName().c_str()));
            QTableWidgetItem* pressInfoItem = new QTableWidgetItem(codec->toUnicode(book.getPressInfo().c_str()));
            QTableWidgetItem* pagesItem = new QTableWidgetItem((QString::number(book.getPage())));
            QTableWidgetItem* priceItem = new QTableWidgetItem((QString::number(book.getPrice())));
            QTableWidgetItem* numItem = new QTableWidgetItem(QString::number(book.getNum()));

            currentBooksList->setItem(row, 0, authorItem);
            currentBooksList->setItem(row, 1, isbnItem);
            currentBooksList->setItem(row, 2, nameItem);
            currentBooksList->setItem(row, 3, pagesItem);
            currentBooksList->setItem(row, 4, pressInfoItem);
            currentBooksList->setItem(row, 5, priceItem);
            currentBooksList->setItem(row, 6, numItem);
        }
    }

    // 设置列宽，这里的宽度值可以根据实际情况调整
    currentBooksList->setColumnWidth(0, 150);
    currentBooksList->setColumnWidth(1, 150);
    currentBooksList->setColumnWidth(2, 200);
    currentBooksList->setColumnWidth(3, 100);
    currentBooksList->setColumnWidth(4, 200);
    currentBooksList->setColumnWidth(5, 100);
    currentBooksList->setColumnWidth(6, 100);
}

void UserPage::onUserUpdated(CUser* user)
{
    this->user = user;
}

void UserPage::onViewBorrowedBooksClicked()
{
    // 清空之前的显示内容
    borrowedBooksList->clearContents();
    borrowedBooksList->setRowCount(0);

    // 设置表格列数和表头
    borrowedBooksList->setColumnCount(2);
    borrowedBooksList->setEditTriggers(QAbstractItemView::NoEditTriggers);
    QStringList headers;
    headers << "借阅者账号" << "借阅图书";
    borrowedBooksList->setHorizontalHeaderLabels(headers);

    // 获取当前用户的借书信息列表
    std::unordered_multimap<string, string> borrowedBooks = mb.getOutBookMap();

    // 添加借书信息到表格中
    for (const auto& book : borrowedBooks) {
        if (book.first != user->getId()) continue;
        int row = borrowedBooksList->rowCount();
        borrowedBooksList->insertRow(row);

        QTableWidgetItem* bookNameItem = new QTableWidgetItem(codec->toUnicode(book.first.c_str()));
        QTableWidgetItem* authorItem = new QTableWidgetItem(codec->toUnicode(book.second.c_str()));

        borrowedBooksList->setItem(row, 0, bookNameItem);
        borrowedBooksList->setItem(row, 1, authorItem);
    }
    borrowedBooksList->setColumnWidth(0, 500);
    borrowedBooksList->setColumnWidth(1, 500);
}

void UserPage::onShowBorrowedBooksForReturnClicked()
{

    // 设置选择模式为单选整行
    returnableBooksList->setSelectionBehavior(QAbstractItemView::SelectRows);
    returnableBooksList->setSelectionMode(QAbstractItemView::SingleSelection);
}
void UserPage::onBorrowTabClicked()
{
    // 清空之前的显示内容
  
}

loginPage.cpp

#include "LoginPage.h"

LoginPage::LoginPage(QWidget* parent) : QWidget(parent)
{
    // 创建用户名输入框
    usernameEdit = new QLineEdit(this);
    
    // 创建密码输入框，并设置为密码模式
    passwordEdit = new QLineEdit(this);
    setWidgetFontAndSize(passwordEdit);
    setInputBoxHeight(passwordEdit, 35); // 设置用户名输入框高度

    // 创建角色选择下拉框
    roleLoginComboBox = new QComboBox(this);
    roleLoginComboBox->addItems({ "学生", "老师", "管理员" });
    setWidgetFont(roleLoginComboBox);

    // 创建登录按钮
    loginButton = new QPushButton("登录", this);
    setWidgetFont(loginButton);

    // 创建注册按钮
    registerButton = new QPushButton("注册", this);
    setWidgetFont(registerButton);

    // 设置布局
    QVBoxLayout* mainLayout = new QVBoxLayout(this);

    QHBoxLayout* usernameLayout = new QHBoxLayout();
    usernameLayout->addWidget(createStyledLabel("用户名："));
    usernameLayout->addWidget(usernameEdit);
    mainLayout->addLayout(usernameLayout);

    QHBoxLayout* passwordLayout = new QHBoxLayout();
    passwordLayout->addWidget(createStyledLabel("密码："));
    passwordLayout->addWidget(passwordEdit);
    mainLayout->addLayout(passwordLayout);
    QHBoxLayout* roleLoginLayout = new QHBoxLayout();
    roleLoginLayout->addWidget(createStyledLabel("角色："));
    roleLoginLayout->addWidget(roleLoginComboBox);
    mainLayout->addLayout(roleLoginLayout);
    QHBoxLayout* buttonLayout = new QHBoxLayout();
    buttonLayout->addWidget(loginButton);
    buttonLayout->addWidget(registerButton);
    mainLayout->addLayout(buttonLayout);

    // 连接按钮点击事件到相应的槽函数
    connect(loginButton, &QPushButton::clicked, this, &LoginPage::onLoginButtonClicked);
    connect(registerButton, &QPushButton::clicked, this, &LoginPage::onRegisterButtonClicked);
}

void LoginPage::onLoginButtonClicked()
{
    QString account = usernameEdit->text();
    QString password = passwordEdit->text();
    QString role = roleLoginComboBox->currentText();
    CUser* user = nullptr;
    CAdministrator admin;
    if (account.isEmpty() || password.isEmpty())
    {
        QMessageBox::critical(this, "错误", "用户名或密码不能为空！");
        return;
    }
    std::ifstream readFile;
    std::ifstream readFile1;
    if (role == "老师")
    {
        readFile.open("teacherLogin.txt");
        readFile1.open("teacher.txt");
        user = new CTeacher();
    }
    else if(role == "学生")
    {
        readFile1.open("student.txt");
        readFile.open("studentLogin.txt");
        user = new CStudent();
    }
    else
    {
        readFile1.open("admin.txt");
        readFile.open("adminLogin.txt");
        int flag = 0;
        while (!readFile.eof())
        {
            std::string act;
            readFile >> act;
            if (act == account.toStdString())
            {
                std::string pwd;
                readFile >> pwd;
                if (pwd == password.toStdString())
                {
                    QMessageBox::about(this, "登录成功", "登录成功！");
                    flag = 1;
                    while (!readFile1.eof())
                    {

                        readFile1 >> admin;

                        if (admin.getId() == act)
                        {
                            emit adminUpdated(admin);
                            break;
                        }
                    }
                    break;
                }
            }

        }
        if (!flag)
        {
            QMessageBox::critical(this, "错误", "用户名或密码错误！");
            return;
        }
        emit adminLoginSuccess();
        readFile.close();
        readFile1.close();
        return;
    }
    int flag = 0;
    while (!readFile.eof())
    {
        std::string act;
        readFile >> act;
        if (act == account.toStdString())
        {
            std::string pwd;
            readFile >> pwd;
            if (pwd == password.toStdString())
            {
                QMessageBox::about(this, "登录成功", "登录成功！");
                flag = 1;
                while (!readFile1.eof())
                {
              
                    readFile1 >> user;

                    if (user != nullptr && user->getId() == act)
                    {
                        emit userUpdated(user);
                        break;
                    }
                }
                break;
            }
        }

    }
    if (!flag)
    {
        QMessageBox::critical(this, "错误", "用户名或密码错误！");
        return;
    }
    emit loginSuccess();
    readFile.close();
    readFile1.close();
}

void LoginPage::onRegisterButtonClicked()
{
    emit registerButtonClicked();
}

// 设置输入框宽度的函数
void LoginPage::setInputBoxWidth(QWidget* widget, int width)
{
    widget->setFixedWidth(width);
}

// 创建带有指定样式的标签函数
QLabel* LoginPage::createStyledLabel(const QString& text)
{
    QLabel* label = new QLabel(text);
    setWidgetFont(label);
    return label;
}

// 设置输入框字体和大小的函数
void LoginPage::setWidgetFontAndSize(QWidget* widget)
{
    QFont font;
    font.setFamily("宋体");
    font.setPointSize(16);
    widget->setFont(font);
}
void LoginPage::setInputBoxHeight(QWidget* widget, int height)
{
    widget->setFixedHeight(height);
}

// 设置按钮字体的函数
void LoginPage::setWidgetFont(QWidget* widget)
{
    QFont font;
    font.setFamily("宋体");
    font.setPointSize(16);
    widget->setFont(font);
}

register.cpp

#include "RegistrationPage.h"
#include <QFont>

RegistrationPage::RegistrationPage(QWidget* parent) : QWidget(parent)
{
    // 创建用户名输入框
    usernameEdit = new QTextEdit(this);
    setWidgetFontAndSize(usernameEdit);
    setInputBoxHeight(usernameEdit, 35); // 设置用户名输入框高度

    // 创建姓名输入框
    nameEdit = new QTextEdit(this);
    setWidgetFontAndSize(nameEdit);
    setInputBoxHeight(nameEdit, 35); // 设置姓名输入框高度

    // 创建部门输入框
    departmentEdit = new QTextEdit(this);
    setWidgetFontAndSize(departmentEdit);
    setInputBoxHeight(departmentEdit, 35); // 设置部门输入框高度

    // 创建电话输入框
    phoneEdit = new QTextEdit(this);
    setWidgetFontAndSize(phoneEdit);
    setInputBoxHeight(phoneEdit, 35); // 设置电话输入框高度

    // 创建密码输入框，并设置为密码模式
    passwordEdit = new QTextEdit(this);
    setWidgetFontAndSize(passwordEdit);
    setInputBoxHeight(passwordEdit, 35); // 设置密码输入框高度

    // 创建性别选择下拉框
    genderComboBox = new QComboBox(this);
    genderComboBox->addItems({ "男", "女" });
    setWidgetFont(genderComboBox);

    // 创建角色选择下拉框
    roleLoginComboBox = new QComboBox(this);
    roleLoginComboBox->addItems({ "学生", "老师", "管理员" });
    setWidgetFont(roleLoginComboBox);

    // 创建注册按钮
    registerButton = new QPushButton("注册", this);
    setWidgetFont(registerButton);

    // 创建登录按钮
    loginButton = new QPushButton("登录", this);
    setWidgetFont(loginButton);


    
    // 连接注册按钮的点击事件到槽函数
    connect(registerButton, &QPushButton::clicked, this, &RegistrationPage::onRegisterButtonClicked);
    connect(loginButton, &QPushButton::clicked, this, &RegistrationPage::onLoginButtonClicked); // 连接登录按钮点击事件
}

void RegistrationPage::onRegisterButtonClicked()
{
    QString act = usernameEdit->toPlainText();
    QString name = nameEdit->toPlainText();
    QString department = departmentEdit->toPlainText();
    QString phone = phoneEdit->toPlainText();
    QString pwd = passwordEdit->toPlainText();
    QString gender = genderComboBox->currentText();
    QString role = roleLoginComboBox->currentText();

    if (act == "" || name == "" || department == "" || phone == "")
    {
        QMessageBox::critical(this, "错误", "请将信息补充完整！");
        return;
    }

    if (role == "管理员")
    {
        QMessageBox::critical(this, "错误", "管理员无法注册！");
        return;
    }

    std::ofstream writeFile;
    std::ofstream writeFile1;

    if (role == "老师")
    {
        writeFile1.open("teacher.txt", std::ios::app);
        writeFile.open("teacherLogin.txt", std::ios::app);
    }
    else
    {
        writeFile1.open("student.txt", std::ios::app);
        writeFile.open("studentLogin.txt", std::ios::app);
    }

    writeFile << std::endl << act.toStdString() << " " << pwd.toStdString();
    writeFile1 << std::endl << act.toStdString() << " " << name.toStdString() << " " << gender.toStdString() << " " << department.toStdString() << " " << phone.toStdString();

    writeFile.close();
    writeFile1.close();

    QMessageBox::about(this, "注册成功", "快去登录系统吧");

    // 发射注册成功信号
    emit registrationSuccess();
}

void RegistrationPage::onLoginButtonClicked()
{
    
}

// 设置控件字体和字号的函数
void RegistrationPage::setWidgetFont(QWidget* widget)
{
    QFont font;
    font.setFamily("宋体");
    font.setPointSize(16);
    widget->setFont(font);
}

// 设置输入框宽度的函数
void RegistrationPage::setInputBoxWidth(QWidget* widget, int width)
{
    widget->setFixedWidth(width);
}

// 创建带有指定样式的标签函数
QLabel* RegistrationPage::createStyledLabel(const QString& text)
{
    QLabel* label = new QLabel(text);
    setWidgetFont(label);
    return label;
}

// 设置输入框字体和大小的函数
void RegistrationPage::setWidgetFontAndSize(QWidget* widget)
{
    QFont font;
    font.setFamily("宋体");
    font.setPointSize(16);
    widget->setFont(font);
}

void RegistrationPage::setInputBoxHeight(QWidget* widget, int height)
{
    widget->setFixedHeight(height);
}

CAdministrator.cpp

cout<<需要完整源码，只需10元<<endl;
cout<<源码+讲解，只需25元 需要请加位心:ch18384322303，备注：图书管理系统GUI源码<<endl;
cout<<讲解包括:<<endl;
cout<<项目讲解视频（如何运行，环境安装，代码思路等）、qt安装流程、qt安装包<<endl;
cout<<本项目问题答疑(不限次数)<<endl;