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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;}/// <summary>/// 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/// </summary>/// <param name="strQuery">查询命令</param>/// <param name="dt">返回数据表</param>/// <returns></returns>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;}/// <summary>/// 执行带参数的查询语句，使用前传入参数、DataTable实例化对象/// </summary>/// <param name="strQuery">查询语句</param>/// <param name="param"></param>/// <param name="dt"></param>/// <returns></returns>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();}/// <summary>/// 查询子窗体是否存在/// </summary>/// <param name="childfrmname"></param>/// <returns></returns>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}/// <summary>/// 用户登录菜单的事件处理/// </summary>/// <param name="sender"></param>/// <param name="e"></param>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;}}/// <summary>/// 用户登录按钮事件/// </summary>/// <param name="sender"></param>/// <param name="e"></param>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;}}/// <summary>/// 图书查询按钮，转到图书查询界面/// </summary>/// <param name="sender"></param>/// <param name="e"></param>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frmBookSearchfrmBookSearch.Show();}/// <summary>/// 图书借阅按钮，转到图书借阅界面/// </summary>/// <param name="sender"></param>/// <param name="e"></param>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frmBookBrownfrmBookBrown.Show();}/// <summary>/// 图书插入按钮，转到图书插入界面/// </summary>/// <param name="sender"></param>/// <param name="e"></param>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frmBookInfrmBookIn.Show();}/// <summary>/// 图书更新/删除按钮，转到图书更新与删除界面/// </summary>/// <param name="sender"></param>/// <param name="e"></param>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frmUpdateBookfrmUpdateBook.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");}}}/// <summary>/// 验证合法性/// </summary>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;}//设置列名标题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);/// <summary>/// 图书借阅按钮/// </summary>/// <param name="sender"></param>/// <param name="e"></param>private void btnBrown_Click(object sender, EventArgs e){//获取下拉框中选中图书的IDint 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(""); }}/// <summary>/// 图书名称选项变化的事件/// </summary>/// <param name="sender"></param>/// <param name="e"></param>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();}/// <summary>/// 图书插入按钮/// </summary>/// <param name="sender"></param>/// <param name="e"></param>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;//设置列名标题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];}}}/// <summary>/// 退出图书界面按钮/// </summary>/// <param name="sender"></param>/// <param name="e"></param>private void btnExit_Click(object sender, EventArgs e){this.Close();}/// <summary>/// 输入合法性验证/// </summary>/// <returns></returns>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);/// <summary>/// 保存信息/// </summary>/// <param name="sender"></param>/// <param name="e"></param>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;}//设置列名标题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];}}/// <summary>/// 更新信息/// </summary>/// <param name="sender"></param>/// <param name="e"></param>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);}}}/// <summary>/// 删除信息/// </summary>/// <param name="sender"></param>/// <param name="e"></param>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);}}}}/// <summary>/// 取消/// </summary>/// <param name="sender"></param>/// <param name="e"></param>private void btnCancel_Click(object sender, EventArgs e){}/// <summary>/// 验证输入合法性/// </summary>/// <returns></returns>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。