zoukankan html css js c++ java

ADO.NET – 3.书籍管理系统详解

内容提要：

1.先写应用程序配置文件app.config

2.创建SQLHelper.cs

3.加载Form的load事件

4.搜索事件

5.点击书籍列表显示具体数据

    5.1先修改为全行选中

    5.2事件dgv_Books_CellClick(object sender, DataGridViewCellEventArgs e)

        ：选中一行，下面显示具体数据

6.新增

7.修改

8.删除

9.退出

效果图：

1.先写应用程序配置文件app.config

app.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <connectionStrings>
    <add name="conStr" connectionString="Server=.\SQLEXPRESS;database=tangsansan;uid=sa;pwd=sa" />
  </connectionStrings>
</configuration>

2.创建SQLHelper.cs

SQlHepler.cs

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Configuration;
 6 using System.Data;
 7 using System.Data.SqlClient;
 8 
 9 
10 namespace BMS
11 {
12     public static class SQLHelper
13     {
14         private static string conStr = ConfigurationManager.
15             ConnectionStrings["conStr"].ConnectionString;
16 
17         private static SqlConnection conn;
18 
19         //连接通道 属性
20         #region 连接通道 属性
21         public static SqlConnection Conn
22         {
23             get
24             {
25                 if (conn == null || conn.State == ConnectionState.Broken)
26                 {
27                     conn = new SqlConnection(conStr);
28                 }
29                 return conn;
30             }
31         }
32         #endregion
33         /// <summary>
34         /// 获取数据表
35         /// </summary>
36         /// <param name="sqlStr">查询语句</param>
37         /// <param name="paras">参数数组</param>
38         /// <returns>结果表</returns>
39         public static DataTable GetDataTable(string sqlStr, params SqlParameter[] paras)
40         {
41             SqlCommand cmd = new SqlCommand(sqlStr, Conn);
42             if (paras.Length > 0)
43             {
44                 cmd.Parameters.AddRange(paras);
45             }
46             SqlDataAdapter adapter = new SqlDataAdapter(cmd);
47             DataTable dt = new DataTable();
48             try
49             {
50                 adapter.Fill(dt);
51             }
52             catch (Exception ex)
53             {
54 
55                 throw ex;
56             }
57             return dt;
58         }
59         /// <summary>
60         /// 执行SQL
61         /// </summary>
62         /// <param name="sql"></param>
63         /// <param name="parameters"></param>
64         /// <returns></returns>
65         public static int ExecNonQuery(string sql, SqlParameter[] parameters)
66         {
67 
68             using (SqlCommand cmd = new SqlCommand(sql, conn))
69             {
70                 if (parameters.Length > 0 && parameters != null)
71                 {
72                     cmd.Parameters.AddRange(parameters);
73                 }
74                 conn.Open();
75                 int res = 0;
76                 try
77                 {
78                     res = cmd.ExecuteNonQuery();
79                 }
80                 catch (Exception e)
81                 {
82                     throw e;
83                 }
84                 finally
85                 {
86                     conn.Close();
87                 }
88                 return res;
89             }          
90         }
91     }
92 }

3.加载Form的load事件

Form_load事件

```
        //窗体加载事件
```

        private void Form1_Load(object sender, EventArgs e)

```
      {
```
```
          LoadBooks();
```
```
          LoadCategory();
```
```
      }
```

        /// <summary>

        /// 加载dgv_Books：（dategridview列表）

        /// </summary>

        private void LoadBooks()

            string sqlStr = "select b_Id,c_name,b_title,b_content,b_author,b_isdel,b_addtime,b_money,b_submoney " +

                            "from Book inner join Category on b_Cid = c_id where b_isdel = 0";

            DataTable dt = SQLHelper.GetDataTable(sqlStr);

            dgv_Books.DataSource = dt;

        /// <summary>

        /// 加载cb_Cate：（书籍类别）

        /// </summary>

        private void LoadCategory()

            string sqlStr = "select * from Category where c_isdel=0";

            DataTable dt = SQLHelper.GetDataTable(sqlStr);

            foreach (DataRow dr in dt.Rows)

                Category model = new Category();

                if (dr["c_id"] != null)

                    model.Cid = Convert.ToInt32(dr["c_id"]);

                model.CName = dr["c_Name"].ToString();

                model.CRemark = dr["c_remark"].ToString();

                model.CIsdel = bool.Parse(dr["c_isdel"].ToString());

                model.CAddtime = Convert.ToDateTime(dr["c_addtime"].ToString());

                model.CParentId = int.Parse(dr["c_parentId"].ToString());

                cb_Cate.Items.Add(model);

            cb_Cate.DisplayMember = "CName";

            cb_Cate.ValueMember = "Cid";

            cb_Cate.SelectedIndex = 0;

4.搜索事件

        private void btn_Serch_Click(object sender, EventArgs e)

            //获得关键字文本框的文本内容

            string txtkey = this.txt_key.Text.Trim();

            //获取下拉框选中项，转成Category，获取类别ID

            int cate = ((Category)cb_Cate.SelectedItem).Cid;

            string sqlStr = "select b_Id,c_name,b_title,b_content,b_author,b_isdel,b_addtime,b_money,b_submoney " +

                            "from Book inner join Category on b_Cid = c_id where b_cid=@cid";

            //如果关键字不为空

            if (!string.IsNullOrEmpty(txtkey))

                sqlStr += string.Format(" and b_title like '%{0}%'", txtkey);

            //得到@cid的值

            SqlParameter sq =new SqlParameter("@cid",SqlDbType.Int,4);

            sq.Value = cate;

            //绑定dgv

            DataTable dt = SQLHelper.GetDataTable(sqlStr,sq);

            dgv_Books.DataSource = dt;

5.点击书籍列表显示具体数据

5.1先修改为全行选中

5.2事件dgv_Books_CellClick(object sender, DataGridViewCellEventArgs e)

：选中一行，下面显示具体数据

         //书籍列表的单元格点击事件

         private void dgv_Books_CellClick(object sender, DataGridViewCellEventArgs e)

            int rowindex = e.RowIndex;

            //ID

            string bid = dgv_Books.Rows[rowindex].Cells[0].Value.ToString();

            lab_ID.Text = bid;

            //书名：txt_title

            string title = dgv_Books.Rows[rowindex].Cells[2].Value.ToString();

            txt_title.Text = title;

            //内容：txt_Content

            string content = dgv_Books.Rows[rowindex].Cells[3].Value.ToString();

            txt_Content.Text = content;

            //作者：txt_author

            string author = dgv_Books.Rows[rowindex].Cells[4].Value.ToString();

            txt_author.Text = author;

            //SelectedItem选择的是Item添加cb_Cate.Items.Add的值

              //如果绑定的datasource，SelectedValue选择的是cb_bookcate.ValueMember的值

              //Cells[9]是c_id的值，一般选择隐藏

              cb_bookcate.SelectedValue = dgv_Books.Rows[rowindex].Cells[9].Value.ToString();

效果图：

6.新增

        #region 新增

        private void btn_Add_Click(object sender, EventArgs e)

            string title = this.txt_title.Text.Trim();

            string author = this.txt_author.Text.Trim();

            string bCid = this.cb_bookcate.SelectedValue.ToString();

            string content = txt_Content.Text.Trim();

            StringBuilder strSql = new StringBuilder();

            strSql.Append("insert into book(");

            strSql.Append("b_Cid,b_title,b_content,b_author)");

            strSql.Append(" values (");

            strSql.Append("@b_Cid,@b_title,@b_content,@b_author)");

            strSql.Append(";select @@IDENTITY");

            SqlParameter[] parameters =

                    new SqlParameter("@b_Cid", SqlDbType.Int, 4),

                    new SqlParameter("@b_title", SqlDbType.VarChar, 200),

                    new SqlParameter("@b_content", SqlDbType.VarChar, 200),

                    new SqlParameter("@b_author", SqlDbType.VarChar, 200)

};

            parameters[0].Value = bCid;

            parameters[1].Value = title;

            parameters[2].Value = content;

            parameters[3].Value = author;

            int res = SQLHelper.ExecNonQuery(strSql.ToString(), parameters);

            //执行成功则刷新列表

            if (res > 0)

                LoadBooks();

                MessageBox.Show("新增成功！");

            else

                MessageBox.Show("新增失败！");

        #endregion

7.修改

        #region 修改

        private void btn_Update_Click(object sender, EventArgs e)

            string bId = this.lab_ID.Text;

            string title = this.txt_title.Text.Trim();

            string author = this.txt_author.Text.Trim();

            string bCid = this.cb_bookcate.SelectedValue.ToString();

            string content = txt_Content.Text.Trim();

            string sqlStr = string.Format("update book set b_title=@title," +

                                          "b_content=@content,b_author=@author,b_cid=@cid" +

                                          " where b_id=@bid");

            SqlParameter[] parameters =

                    new SqlParameter("@title", SqlDbType.VarChar, 200),

                    new SqlParameter("@content", SqlDbType.VarChar, 200),

                    new SqlParameter("@author", SqlDbType.VarChar, 200),

                    new SqlParameter("@cid", SqlDbType.Int, 4),

                    new SqlParameter("@bid", SqlDbType.Int, 4),

};

            //为参数数组中的每个参数赋值

            parameters[0].Value = title;

            parameters[1].Value = content;

            parameters[2].Value = author;

            parameters[3].Value = bCid;

            parameters[4].Value = bId;

            int res = SQLHelper.ExecNonQuery(sqlStr, parameters);

            //执行成功则刷新列表

            if (res>0)

                LoadBooks();

                MessageBox.Show("修改成功！");

            else

                MessageBox.Show("修改不成功！");

        #endregion

8.删除

private void btn_Del_Click(object sender, EventArgs e)

     string bId = this.lab_ID.Text;

     StringBuilder strSql = new StringBuilder();

     strSql.Append("delete from book ");

     strSql.Append(" where b_id=@cid");

     SqlParameter[] parameters = {

             new SqlParameter("@cid", SqlDbType.Int,4)

};

     parameters[0].Value = bId;

     int res = SQLHelper.ExecNonQuery(strSql.ToString(), parameters);

     //执行成功则刷新列表

     if (res > 0)

         LoadBooks();

         MessageBox.Show("删除成功！");

     else

         MessageBox.Show("删除失败！");

9.退出

//退出

private void btn_Out_Click(object sender, EventArgs e)

    //this.Close();

    //只是关闭了当前窗口，若不是主窗体的话，是无法退出整个程序的，

    //另外若有托管线程（非主线程）如指针之类的，也无法干净地退出。

    //Application.Exit();

    //强制所有消息中止，退出所有的窗体，但是若有托管线程（非主线程），也无法干净地退出。

    //Application.ExitThread();

    //强制中止调用线程上的所有消息，无法控制多线程正确退出的问题；

    //System.Environment.Exit(0);

    //这是最彻底的退出方式，不管什么线程都被强制退出，把程序结束的很干净。

    System.Environment.Exit(System.Environment.ExitCode);

    //所以在程序中需要强制退出的地方加上System.Environment.Exit(System.Environment.ExitCode);

    //还有一种方法：  System.Threading.Thread.CurrentThread.Abort();

    //或者  Process.GetCurrentProcess().Kill()

    //或者  Application.ExitThread();

    //或者  Application.ExitThread()

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原文地址：https://www.cnblogs.com/tangge/p/2739068.html