【C#项目】图书馆管理系统-WinForm+MySQL

文章目录

• 前言
• 一、业务梳理与需求分析
• • • 1.功能描述
    • 2.实现步骤
    • 3.功能逻辑图
• 二、数据库设计
• • • 1.实体-关系（E-R图）概念模型设计
    • 2.数据表设计
• 三、WinForm界面交互设计
• • • 1、界面交互逻辑
    • 2、项目树
    • 3、主界面+登录界面
    • 4、 图书查询界面
    • 5、图书借阅界面
    • 6、图书插入界面
    • 7、图书更新/删除界面
• 四、通用类设计
• • • 1、与MySQL通讯模块（整个类模块中删除命名空间等，值保留这个类）
    • 2、数据库操作模块：
• 五、系统代码实现与分析
• • • 1、主界面代码：
    • 2、登录界面代码
    • 3、图书查询模块代码
    • 4、图书借阅代码
    • 5、图书插入代码
    • 6、图书更新/删除代码
• 总结

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前言

图书馆管理系统主要功能有普通用户（学生）借书、管理员管理图书。

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一、业务梳理与需求分析

1.功能描述

• 系统中的普通用户模块有以下功能：
  图书查询：根据输入的搜索条件进行查询，可以查找多项，也可以查找所有图书。
  图书借阅：提供图书借阅证号，可以进行图书借阅。
• 系统中的管理员用户模块有以下功能：
  图书查询：查询图书信息。
  图书借阅：提供图书借阅证号，可以进行图书借阅。
  增加图书：增添新图书。
  修改图书：对图书信息进行修改。
  删除图书：删除过时的、不能借阅的图书。

2.实现步骤

• 一个完整系统的数据库设计。
• 图书馆管理系统的界面设计。
• 项目的通用类。
• 图书馆管理系统代码的实现和分析。

3.功能逻辑图

二、数据库设计

1.实体-关系（E-R图）概念模型设计

2.数据表设计

根据需求分析进行数据库设计，数据库名称为BookManage，根据E-R图，有学生表、图书信息表、管理员表、借阅表。学生和管理员合并为一张用户表，增加一个字段用户权限进行区分。

• 用户表结构

  

• 图书信息表结构
  

• 图书借阅信息表结构
  

三、WinForm界面交互设计

1、界面交互逻辑

2、项目树

3、主界面+登录界面

4、 图书查询界面

5、图书借阅界面

6、图书插入界面

7、图书更新/删除界面

四、通用类设计

1、与MySQL通讯模块（整个类模块中删除命名空间等，值保留这个类）

public static class DBModule{    public static string ServerIP = "**.**.**.**";    public static string ServerPort = "****";    public static string ServerUser = "****";    public static string ServerPassword = "****";    public static string ServerDBName = "bookmanage";}

2、数据库操作模块：

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;using MySql.Data.MySqlClient;using System.Data;public class MySQLHelper{    private MySqlConnection myConnection;    private string mErrorString;    //构造函数    public MySQLHelper(string strServerIP, string strServerPort, string strServerUser, string strPassword, string strDBName)    {        string strConnectionString = String.Format("server={0}; port={1}; user id={2}; password={3}; database={4}",             strServerIP, strServerPort, strServerUser, strPassword, strDBName);        myConnection = new MySqlConnection(strConnectionString);    }    //测试连接    public bool ConnectionTest()    {        bool result = false;        try        {            if (myConnection.State == System.Data.ConnectionState.Closed)            {                myConnection.Close();                result = true;            }        }        catch (MySqlException ex)        {            mErrorString = ex.ToString();        }        return result;    }    /// 
    /// 执行查询语句，用DataTable返回结果，调用前要传入DataTable的实例化对象作为参数    ///     /// 查询命令    /// 返回数据表    ///     public bool ExcuteQuerySql(string strQuery, ref DataTable dt)    {        if (dt == null)        {            mErrorString = "传入的DataTable为null";            return false;        }        bool result = false;        try        {            MySqlCommand myCommand = new MySqlCommand(strQuery);            myCommand.Connection = myConnection;            if (myConnection.State == ConnectionState.Closed)            {                myConnection.Open();            }            dt.Load(myCommand.ExecuteReader());            result = true;        }        catch (MySqlException ex)        {            mErrorString = String.Format("ExcuteQuery {0} failed.", ex.ToString());            return false;        }        finally        {            myConnection.Close();        }        return result;    }    /// 
    /// 执行带参数的查询语句，使用前传入参数、DataTable实例化对象    ///     /// 查询语句    ///     ///     ///     public bool ExcuteQuerySql(string strQuery, MySqlParameter[] param, ref DataTable dt)    {        if (dt == null)        {            mErrorString = "传入的DataTable为null.";            return false;        }        bool result = false;        try        {            MySqlCommand myCommand = new MySqlCommand(strQuery);            myCommand.Connection = myConnection;            if (myConnection.State == ConnectionState.Closed)            {                myConnection.Open();            }            for (int i = 0; i < param.Length; i++)            {                myCommand.Parameters.Add(param[i]);            }            dt.Load(myCommand.ExecuteReader());            result = true;        }        catch (MySqlException ex)        {            mErrorString = String.Format("ExcuteQuery {0} failed", strQuery) + ex.Message;            return false;        }        finally        {            myConnection.Close();        }        return result;    }    //执行非查询语句    public int ExcuteSql(string SqlCmdText)    {        int row = -1;        try        {            MySqlCommand myCommand = new MySqlCommand(SqlCmdText);            myCommand.CommandText = SqlCmdText;            myCommand.Connection = myConnection;            if (myConnection.State == ConnectionState.Closed)            {                myConnection.Open();            }            row = myCommand.ExecuteNonQuery();        }        catch (MySqlException ex)        {            mErrorString = String.Format("ExcuteNonQuery {0} failed", SqlCmdText);        }        return row;    }    //执行非查询语句    public int ExcuteSql(string[] SqlCmdText)    {        try        {            if (myConnection.State == ConnectionState.Closed)            {                myConnection.Open();            }            for (int i = 0; i < SqlCmdText.Length; i++)            {                MySqlCommand myCommand = new MySqlCommand(SqlCmdText[i]);                myCommand.CommandText = SqlCmdText[i];                myCommand.Connection = myConnection;                myCommand.ExecuteNonQuery();            }        }        catch (MySqlException ex)        {            mErrorString = String.Format("ExcuteNonQuery {0} failed", SqlCmdText) + ex.Message;            return -1;        }        return -1;    }    //执行带参数的非查询语句    public int ExcuteSql(string SqlCmdText, MySqlParameter[] param)    {        int row = -1;        try        {            MySqlCommand myCommand = new MySqlCommand(SqlCmdText);            myCommand.CommandText = SqlCmdText;            myCommand.Connection = myConnection;            if (myConnection.State == ConnectionState.Closed)            {                myConnection.Open();            }            for (int i = 0; i < param.Length; i++)            {                myCommand.Parameters.Add(param[i]);            }            row = myCommand.ExecuteNonQuery();        }        catch (MySqlException ex)        {            mErrorString = String.Format("ExecuteNonQuery {0} failed", SqlCmdText) + ex.Message;            return row = -1;        }        return row;    }    public string GetErrInfo()    {        return mErrorString;    }}

五、系统代码实现与分析

1、主界面代码：

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace BookManage{    public partial class FrmMain : Form    {        public static DialogResult result;//声明对话框返回对象        public FrmMain()        {            InitializeComponent();        }        /// 
        /// 查询子窗体是否存在        ///         ///         ///         public bool CheckChildFrm(string childfrmname)        {            foreach (Form childFrm in this.MdiChildren)//遍历子窗体            {                if (childFrm.Name == childfrmname)//如果子窗体存在                {                    if (childFrm.WindowState == FormWindowState.Minimized)                    {                        childFrm.WindowState = FormWindowState.Normal;                    }                    childFrm.Activate();//激活该窗体                    return true;        //存在返回true                }            }            return false;//不存在返回false        }        /// 
        /// 用户登录菜单的事件处理        ///         ///         ///         private void 用户登录ToolStripMenuItem_Click(object sender, EventArgs e)        {            //检测登录窗口是否打开            if (this.CheckChildFrm("FrmLogin") == true)            {                return;//窗口已经打开，返回            }            FrmLogin user = new FrmLogin();//实例化登录窗体            user.ShowDialog();//登录窗体以模式对话框的方式打开                        //判断是否登录成功，登录成功则启用相应的菜单和按钮            if (result == System.Windows.Forms.DialogResult.OK && FrmLogin.ustate == 0)//普通用户            {                toolSBSearch.Enabled = true;                toolSBBookBorown.Enabled = true;            }            else if (result == System.Windows.Forms.DialogResult.OK && FrmLogin.ustate == 1)//管理员            {                toolSBSearch.Enabled = true;                toolSBBookBorown.Enabled = true;                toolMBookManage.Enabled = true;            }        }        /// 
        /// 用户登录按钮事件        ///         ///         ///         private void toolSBLogin_Click(object sender, EventArgs e)        {            //检测登录窗口是否打开            if (this.CheckChildFrm("FrmLogin") == true)            {                return;//窗口已经打开，返回            }            FrmLogin user = new FrmLogin();//实例化登录窗体            user.ShowDialog();//登录窗体以模式对话框的方式打开            //判断是否登录成功，登录成功则启用相应的菜单和按钮            if (result == System.Windows.Forms.DialogResult.OK && FrmLogin.ustate == 0)//普通用户            {                //普通用户登录后使能按钮                toolSBSearch.Enabled = true;                toolSBBookBorown.Enabled = true;            }            else if (result == System.Windows.Forms.DialogResult.OK && FrmLogin.ustate == 1)//管理员            {                //管理员登录后使能按钮                toolSBSearch.Enabled = true;                toolSBBookBorown.Enabled = true;                toolMBookManage.Enabled = true;            }        }        /// 
        /// 图书查询按钮，转到图书查询界面        ///         ///         ///         private void toolSBSearch_Click(object sender, EventArgs e)        {            if (this.CheckChildFrm("FrmBookSearch") == true)            {                return;            }            FrmBookSearch frmBookSearch = new FrmBookSearch();            frmBookSearch.MdiParent = this;//设置当前窗体的子窗体为frmBookSearch            frmBookSearch.Show();        }        /// 
        /// 图书借阅按钮，转到图书借阅界面        ///         ///         ///         private void toolSBBookBorown_Click(object sender, EventArgs e)        {            if (this.CheckChildFrm("FrmBookBrown") == true)            {                return;            }            FrmBookBrown frmBookBrown = new FrmBookBrown();            frmBookBrown.MdiParent = this;//设置当前窗体的子窗体为frmBookBrown            frmBookBrown.Show();        }        /// 
        /// 图书插入按钮，转到图书插入界面        ///         ///         ///         private void toolMBookIn_Click(object sender, EventArgs e)        {            if (this.CheckChildFrm("FrmBookIn") == true)            {                return;            }            FrmBookIn frmBookIn = new FrmBookIn();            frmBookIn.MdiParent = this;//设置当前窗体的子窗体为frmBookIn            frmBookIn.Show();        }        /// 
        /// 图书更新/删除按钮，转到图书更新与删除界面        ///         ///         ///         private void toolMBookUpdate_Click(object sender, EventArgs e)        {            if (this.CheckChildFrm("FrmUpdateBook") == true)            {                return;            }            FrmUpdateBook frmUpdateBook = new FrmUpdateBook();            frmUpdateBook.MdiParent = this;//设置当前窗体的子窗体为frmUpdateBook            frmUpdateBook.Show();        }        private void toolSBExit_Click(object sender, EventArgs e)        {            if (MessageBox.Show("确认退出程序？", "确认信息", MessageBoxButtons.OKCancel) == System.Windows.Forms.DialogResult.OK)            {                System.Environment.Exit(0);            }        }    }}

2、登录界面代码

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace BookManage{    public partial class FrmLogin : Form    {        public FrmLogin()        {            InitializeComponent();        }        public static int ustate;//普通用户or管理员标志        FrmMain femmain = new FrmMain();        private void btnLogin_Click(object sender, EventArgs e)        {            //输入合法性判断            if (Volidity())//合法性通过            {                string state = this.cmbUserType.Text;                int num;                if (state.Equals("管理员"))//判断用户角色                {                    num = 1;                }                else                {                    num = 2;                }                //定义查询语句                string sql = String.Format("select * from user where uname='{0}' and upwd='{1}' and ustate='{2}'",                 this.txtUserName.Text.Trim(), this.txtPwd.Text.Trim(), num);                MySQLHelper sqlHelper = new MySQLHelper(DBModule.ServerIP, DBModule.ServerPort, DBModule.ServerUser, DBModule.ServerPassword, DBModule.ServerDBName); DataTable dt = new DataTable();    bool queryFlag = sqlHelper.ExcuteQuerySql(sql, ref dt);                if (queryFlag == false)                {                    MessageBox.Show("登录失败，没有找到该用户");                }                if (dt.Rows.Count > 0)                {                    MessageBox.Show("登录成功！");                    FrmMain.result = DialogResult.OK;//为变量result赋值                    DBModule.UserName = txtUserName.Text;                    this.Close();                }                else                {                    MessageBox.Show("用户名或密码错误，请重新输入");                }            }        }        /// 
        /// 验证合法性        ///         private bool Volidity()        {            if (this.txtPwd.Text != string.Empty && this.txtPwd.Text != string.Empty)            {                return true;            }            else            {                MessageBox.Show("用户名或密码不能为空");            }            return false;        }        private void btnCancel_Click(object sender, EventArgs e)        {            this.Close();        }        private void cmbUserType_SelectedIndexChanged(object sender, EventArgs e)        {            if (cmbUserType.SelectedIndex == 0)            {                cmbUserType.Text = "普通用户";                ustate = 0;            }            else            {                cmbUserType.Text = "管理员";                ustate = 1;            }        }        private void FromLogin_Load(object sender, EventArgs e)        {            this.cmbUserType.SelectedIndex = 0;            ustate = 0;        }    }}

3、图书查询模块代码

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace BookManage{    public partial class FrmBookSearch : Form    {        public FrmBookSearch()        {            InitializeComponent();        }        private void btnSearch_Click(object sender, EventArgs e)        {            string strBookType = cmbBokTyp.Text;            string strBookTypeOr = cmbBokTypOr.Text;            string strBookName = txtBokNm.Text;            string strBookNameOr = txtBokNmOr.Text;            string strBookConment = txtBokCotnt.Text;            //定义sql语句            string sql = "SELECT * FROM book WHERE booktype='" + strBookType + "'" + "or booktype='" + strBookTypeOr + "'" +                 " and bookname='" + strBookName + "';";            MySQLHelper sqlHelper = new MySQLHelper(DBModule.ServerIP, DBModule.ServerPort, DBModule.ServerUser, DBModule.ServerPassword, DBModule.ServerDBName);            DataTable dt = new DataTable();            bool queryFlag = sqlHelper.ExcuteQuerySql(sql, ref dt);            if (queryFlag == false)            {                MessageBox.Show("查询失败，没有该图书信息");            }            if (dt.Rows.Count > 0)            {                dgvBookSearch.DataSource = dt;            }            //设置列名            string[] strColumnName = { "图书ID", "图书类别", "书名", "作者", "价格", "封面", "内容简介", "指定访问码"};            for (int i = 0; i < dgvBookSearch.Columns.Count; i++){                dgvBookSearch.Columns[i].HeaderText = strColumnName[i];}        }        private void btnClose_Click(object sender, EventArgs e)        {            this.Close();        }        private void FrmBookSearch_Load(object sender, EventArgs e)        {            //图书类别的初始化            string sql = "SELECT DISTINCT booktype FROM book;";            MySQLHelper sqlHelper = new MySQLHelper(DBModule.ServerIP, DBModule.ServerPort, DBModule.ServerUser, DBModule.ServerPassword, DBModule.ServerDBName);            DataTable dtTtpe = new DataTable();            try            {                bool queryFlag = sqlHelper.ExcuteQuerySql(sql, ref dtTtpe);                if (queryFlag == false)                {                    MessageBox.Show("查询图书类型失败");                }            }            catch (Exception ex)            {                MessageBox.Show("查询图书类型失败" + ex.ToString());            }            if (dtTtpe.Rows.Count > 0)            {                for (int i = 0; i < dtTtpe.Rows.Count; i++)                {                    this.cmbBokTyp.Items.Add(dtTtpe.Rows[i][0].ToString());                    this.cmbBokTypOr.Items.Add(dtTtpe.Rows[i][0].ToString());                }            }            this.cmbBokTyp.SelectedIndex = 0;            this.cmbBokTypOr.SelectedIndex = 0;        }    }}

4、图书借阅代码

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace BookManage{    public partial class FrmBookBrown : Form    {        public FrmBookBrown()        {            InitializeComponent();        }        DataTable dt = new DataTable();        MySQLHelper sqlHelper = new MySQLHelper(DBModule.ServerIP, DBModule.ServerPort, DBModule.ServerUser, DBModule.ServerPassword, DBModule.ServerDBName);        /// 
        /// 图书借阅按钮        ///         ///         ///         private void btnBrown_Click(object sender, EventArgs e)        {            //获取下拉框中选中图书的ID            int bookid = Convert.ToInt32(this.cmbBookName.SelectedIndex + 1);            //获取用户的借阅证            int issid = Convert.ToInt32(this.txtIssueID.Text);            //获取借阅时间            DateTime date = Convert.ToDateTime(this.IssDatetime.Text);            //更新借阅信息            string sql = "insert into bookbrown (bookid, issbookid, issdatetime) values ('" + bookid + "', '" + issid + "', '" + date + "');";            //借阅信息中没有这本书才可借阅            DataTable dtC = new DataTable();            sqlHelper.ExcuteQuerySql("select bookid from bookbrown;", ref dtC);            int flagTmp = 0;            for (int i = 0; i < dtC.Rows.Count; i++)            {                if (Convert.ToInt32(dtC.Rows[i][0].ToString()) == bookid)                {                    flagTmp = 1;                }            }            if (flagTmp == 1)            {                MessageBox.Show("这本书你已经借阅过，借阅不能超过1本", "提示信息", MessageBoxButtons.OK);            }            else            {                if (sqlHelper.ExcuteSql(sql) == 1)                {                    MessageBox.Show("借阅成功");                }                else                {                    MessageBox.Show("借阅失败");                }            }                        //刷新借阅证中的图书信息            string sqlQ = "select bookinfo.bookid,bookname,issbookid,issdatetime from bookbrown,bookinfo where bookinfo.bookid=bookbrown.bookid;";                       bool queryFlagQ = sqlHelper.ExcuteQuerySql(sqlQ, ref dt);            if (queryFlagQ == true)            {                this.dataGridView1.DataSource = dt;            }        }        private void btnCancel_Click(object sender, EventArgs e)        {            this.Close();        }        private void FrmBookBrown_Load(object sender, EventArgs e)        {            string sql = "select * from bookinfo;";            //联合图书信息表、借阅信息表查询            string sqlBro = "select bookinfo.bookid,bookname,issbookid,issdatetime from bookbrown,bookinfo where bookinfo.bookid=bookbrown.bookid;"; //主键与外键的关联            try            {                bool queryFlag = sqlHelper.ExcuteQuerySql(sql, ref dt);//查询图书信息                if (queryFlag == false)                {                    MessageBox.Show("查询失败");                }                else                {                    //自动加载图书名到下拉框                    for (int i = 0; i < dt.Rows.Count; i++)                    {                        this.cmbBookName.Items.Add(dt.Rows[i][1].ToString());                    }                }               //联合查询查询本人借阅信息                DataTable dtBro=new DataTable();                bool queryFlagBro = sqlHelper.ExcuteQuerySql(sqlBro, ref dtBro);                if (queryFlagBro == true)                {                    this.dataGridView1.DataSource = dtBro;                }                else                {                    MessageBox.Show("查询借阅信息失败");                }                //查询用户信息                 string sqlU = "select * from user where uname= '" + DBModule.UserName + "';";                DataTable dtU = new DataTable();                bool queryFlagU = sqlHelper.ExcuteQuerySql(sqlU, ref dtU);                if (queryFlagU == true)                {                    this.txtUserName.Text = dtU.Rows[0]["uname"].ToString();                    this.txtIssueID.Text = dtU.Rows[0]["upwd"].ToString();                }    //初始化列名                string[] strColumnName = { "图书编号", "图书名称", "指定访问码", "借阅时间"};                for (int i = 0; i < dt.Columns.Count; i++)                {                    dataGridView1.Columns[i].HeaderText=strColumnName[i];                }            }            catch (Exception ex)            {                MessageBox.Show("");             }                    }        /// 
        /// 图书名称选项变化的事件        ///         ///         ///         private void cmbBookName_SelectedIndexChanged(object sender, EventArgs e)        {            //遍历图书信息表，查询和选中书名相同的信息，加载到界面            foreach (DataRow row in dt.Rows)            {                if (cmbBookName.Text == row["bookname"].ToString())                {                    this.txtBookIssue.Text = row["bookissue"].ToString();                    this.txtBookAuthor.Text = row["bookauthor"].ToString();                }            }        }    }}

5、图书插入代码

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace BookManage{    public partial class FrmBookIn : Form    {        public FrmBookIn()        {            InitializeComponent();        }        /// 
        /// 图书插入按钮        ///         ///         ///         private void btnInsert_Click(object sender, EventArgs e)        {            //定义变量接收控件的值            string strBookType = txtBookType.Text;            string strBookName = txtBookName.Text;            string strAuthor = txtAuthor.Text;            string strPrice = txtPrice.Text;            string strPic = txtPic.Text;            string strContent = txtContent.Text;            string strIssue = txtIssue.Text;            if (Vaildate())            {                //sql语句                string sql = "insert into bookinfo (bookname, booktype, bookauthor, bookprice, bookpic, bookcontent, bookissue)"                    + " values ('" + strBookName + "', '" + strBookType + "', '" + strAuthor + "', '" + strPrice + "', '" +                     strPic + "', '" + strContent + "', '" + strIssue + "');";                MySQLHelper sqlHelper = new MySQLHelper(DBModule.ServerIP, DBModule.ServerPort, DBModule.ServerUser, DBModule.ServerPassword, DBModule.ServerDBName);    int result=sqlHelper.ExcuteSql(sql);                if (result == 1)                {                    MessageBox.Show("添加成功", "提示", MessageBoxButtons.OK);                }                else                {                    MessageBox.Show("添加失败", "提示", MessageBoxButtons.OK);                }                DataTable dt = new DataTable();                sqlHelper.ExcuteQuerySql("select * from bookinfo;", ref dt);                this.dataGridView1.DataSource = dt;                //设置列名                string[] strColumnName = { "图书ID", "图书类别", "书名", "作者", "价格", "封面", "内容简介", "指定访问码" };                for (int i = 0; i < dataGridView1.Columns.Count; i++)                {                    dataGridView1.Columns[i].HeaderText = strColumnName[i];                }            }        }        /// 
        /// 退出图书界面按钮        ///         ///         ///         private void btnExit_Click(object sender, EventArgs e)        {            this.Close();        }        /// 
        /// 输入合法性验证        ///         ///         private bool Vaildate()        {            if (txtBookType.Text != string.Empty && txtBookName.Text != string.Empty && txtAuthor.Text != string.Empty                && txtPrice.Text != string.Empty && txtPic.Text != string.Empty && txtContent.Text != string.Empty && txtIssue.Text != string.Empty)            {                return true;            }            else            {                MessageBox.Show("请出入完整信息");            }            return false;        }    }}

6、图书更新/删除代码

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace BookManage{    public partial class FrmUpdateBook : Form    {        public FrmUpdateBook()        {            InitializeComponent();        }        MySQLHelper sqlHelper = new MySQLHelper(DBModule.ServerIP, DBModule.ServerPort, DBModule.ServerUser, DBModule.ServerPassword, DBModule.ServerDBName);        /// 
        /// 保存信息        ///         ///         ///         private void btnSave_Click(object sender, EventArgs e)        {            string sql = "select * from bookinfo;";            DataTable dt = new DataTable();            if (MessageBox.Show("确实要将修改保存到数据库？", "提示信息", MessageBoxButtons.OKCancel) == System.Windows.Forms.DialogResult.OK)            {                bool queryFlag = sqlHelper.ExcuteQuerySql(sql, ref dt);                if (queryFlag == true)                {                    MessageBox.Show("保存成功");                }                this.dataGridView1.DataSource = dt;            }            //设置列名            string[] strColumnName = { "图书ID", "图书类别", "书名", "作者", "价格", "封面", "内容简介", "指定访问码" };            for (int i = 0; i < dataGridView1.Columns.Count; i++)            {                dataGridView1.Columns[i].HeaderText = strColumnName[i];            }        }        /// 
        /// 更新信息        ///         ///         ///         private void btnUpdate_Click(object sender, EventArgs e)        {            string strBookType = txtBookType.Text;            string strBookName = txtBookName.Text;            string strBookAuthor = txtBookAuthor.Text;            string strBookPrice = txtBookPrice.Text;            string strBookPic = txtBookPic.Text;            string strBookContent = txtBookContent.Text;            string strBookIssue = txtBookIssue.Text;            if (true)            {                string sql = string.Format("update bookinfo set booktype='{0}', bookname='{1}', bookauthor='{2}', bookprice='{3}', bookpic='{4}', bookcontent='{5}',bookissue='{6}' where bookid={7};",                 strBookType, strBookName, strBookAuthor, strBookPrice, strBookPic, strBookContent, strBookIssue, Convert.ToInt32(txtBookID.Text));                if (sqlHelper.ExcuteSql(sql) == 1)                {                    MessageBox.Show("更新成功", "提示信息", MessageBoxButtons.OK);                }                else                {                    MessageBox.Show("更新失败", "提示信息", MessageBoxButtons.OK);                }            }        }        /// 
        /// 删除信息        ///         ///         ///         private void btnDelete_Click(object sender, EventArgs e)        {            if (this.txtBookID.Text != string.Empty)            {                string sql = "select * from bookbrown where bookid=" + Convert.ToInt32(txtBookID.Text) + "";                DataTable dt = new DataTable();                bool queryFlag = sqlHelper.ExcuteQuerySql(sql, ref dt);                if (queryFlag == true && dt.Rows.Count > 0)                {                    MessageBox.Show("此书有借阅，不能删除");                }                else                {                    string sqlDe = "delete from bookinfo where bookid=" + this.txtBookID.Text + "";                    if (sqlHelper.ExcuteSql(sqlDe) == 1)                    {                        MessageBox.Show("删除成功", "提示信息", MessageBoxButtons.OK);                    }                    else                    {                        MessageBox.Show("删除失败", "提示信息", MessageBoxButtons.OK);                    }                }            }        }        /// 
        /// 取消        ///         ///         ///         private void btnCancel_Click(object sender, EventArgs e)        {        }        /// 
        /// 验证输入合法性        ///         ///         private bool Vaildate()        {            if (txtBookType.Text != string.Empty && txtBookName.Text != string.Empty && txtBookAuthor.Text != string.Empty                && txtBookPrice.Text != string.Empty && txtBookPic.Text != string.Empty                && txtBookContent.Text != string.Empty && txtBookIssue.Text != string.Empty && txtBookID.Text != string.Empty)            {                return true;            }            else            {                MessageBox.Show("请出入完整信息");            }            return false;        }    }}    

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总结

本项目实现一个简单的图书馆管理系统，是一个完整的图书馆管理系统的简化版。通过这个项目，了解整个桌面应用软件的规范化开发流程，业务梳理、需求分析、概要设计、详细设计、数据库设计、界面交互设计、详细代码设计等步骤。同时将代码开发规范融入其中，尽量使用较为规范的代码。加深了对WinForm界面控件的认识，对MySQL更加熟悉。数据库SQL语言操作还需要多联系，纸上得来终觉浅，觉知此事要躬行。SQL语句看似简单，实际操作起来是出问题最多的地方。

来源地址：https://blog.csdn.net/qq_38628970/article/details/128912319