电话本管理程序（实现增删改查功能）

由于刚开始学习ADO.NET在Winform上的应用，所以程序编写过程中出现了好多的问题。但是现在问题基本上都解决了，所以今天把代码放上来，给想我这样的初学者们一个思路的提示。用到的控件有：TextBox，ComboBox，button，DataGridView

首先，先放上程序运行后的截图：

上代码：

首先还是APP.config文件,这个文件的作用是连接字符串的时候使用，方便了以后的修改 PS：记得添加引用和命名空间，不会的看我上一篇文章

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <connectionStrings>
        <add name="connStr" connectionString="Data Source=ZIP-CW\MSSQLSERVER0;Initial Catalog=PhoneNumManager;Integrated Security=True"/>
    </connectionStrings>
</configuration>

然后是Group类，这个类的作用是用在ComboBox选择某项的时候可以获得这项的Id号

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace PhoneBook
{
    class Group
    {
        private string pId;

        public string PId
        {
            get { return pId; }
            set { pId = value; }
        }
        private string ptName;

        public string PtName
        {
            get { return ptName; }
            set { ptName = value; }
        }

        public override string ToString()
        {
            return ptName;
        }
    }
}

最后就是整个程序主要的代码了

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Configuration;
using System.Data.SqlClient;

namespace PhoneBook
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        
        //连接字符串
        string conStr = ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;

        private void Form1_Load(object sender, EventArgs e)
        {
            string sql = "select * from [PhoneNum]";
            GetPhoneNum(sql);
            LoadCbo();
            
        }

        /// <summary>
        /// 执行查询数据库功能的方法
        /// </summary>
        /// <param name="sql">查询数据库的语句</param>
        private void GetPhoneNum(string sql)
        {
            using (SqlConnection conn = new SqlConnection(conStr))
            {
                DataSet ds = new DataSet();
                SqlDataAdapter sda = new SqlDataAdapter(sql, conn); //用于查询数据库，并填充DataSet集;创建DataAdapter数据适配器实例
                sda.Fill(ds);   //填充DataSet集
                dgvPhoneBook.DataSource = ds.Tables[0];
            }
        }

        /// <summary>
        /// 获得执行的SQL语句的方法
        /// </summary>
        /// <returns>返回拼接好的SQL语句</returns>
        private string GetString()
        {
            //为了简单和易读性的考虑，使用where 1=1
            StringBuilder sql = new StringBuilder("select * from [PhoneNum] where 1=1 ");
            if (txtName.Text != "")
            {
                sql.AppendLine(" and pName like '%" + txtName.Text.Trim() + "%'");
            }
           
            if (txtPhoneNumber.Text != "")
            {
                sql.AppendLine(" and pCellPhone like '%" + txtPhoneNumber.Text.Trim() + "%'");
            }
            //类型转换
            Group group = cboGroup.SelectedItem as Group;
            if (cboGroup.SelectedItem != null)
            {
                if (group.PId == "1")
                {
                    sql.AppendLine(" and pTypeId=1");                   
                }
                else if (group.PId == "2")
                {
                    sql.AppendLine(" and pTypeId=2");                    
                }
                else if (group.PId == "3")
                {                
                    sql.AppendLine(" and pTypeId=3");                    
                }
                else if (group.PId == "4")
                {                  
                    sql.AppendLine(" and pTypeId=4");                    
                }               
                
            }
            return sql.ToString();
        }
        //查询按钮的响应
        private void btnSearch_Click(object sender, EventArgs e)
        {            
            GetPhoneNum(GetString());
        }        
        //combox下拉列表选择的事件响应
        private void cboGroup_SelectedIndexChanged(object sender, EventArgs e)
        {          
            GetPhoneNum(GetString());           
        }        
        //加载Combox
        private void LoadCbo()
        {
            Group group = new Group();
            group.PtName = "全部";
            group.PId = "0";
            cboGroup.Items.Add(group);
            cboAddGroup.Items.Add(group);

            Group group1 = new Group();
            group1.PtName = "朋友";
            group1.PId = "1";
            cboGroup.Items.Add(group1);
            cboAddGroup.Items.Add(group1);

            Group group2 = new Group();
            group2.PtName = "同事";
            group2.PId = "2";
            cboGroup.Items.Add(group2);
            cboAddGroup.Items.Add(group2);

            Group group3 = new Group();
            group3.PtName = "同学";
            group3.PId = "3";
            cboGroup.Items.Add(group3);
            cboAddGroup.Items.Add(group3);

            Group group4 = new Group();
            group4.PtName = "家人";
            group4.PId = "4";
            cboGroup.Items.Add(group4);
            cboAddGroup.Items.Add(group4);
        }

        /// <summary>
        /// 执行增删改的操作
        /// </summary>
        private void BindDgv()
        {
            string sql = "select * from [PhoneNum] order by pId desc";
            using (SqlConnection conn = new SqlConnection(conStr))
            {
                DataTable dt = new DataTable();
                SqlDataAdapter sda = new SqlDataAdapter(sql,conn);
                sda.Fill(dt);
                dgvPhoneBook.DataSource = dt;
            }
        }      

        //加载增删改部分的combox
        private void LoadAddCbo()
        {
            Group group = new Group();
            group.PtName = "全部";
            group.PId = "0";
            cboAddGroup.Items.Add(group);

            Group group1 = new Group();
            group1.PtName = "朋友";
            group1.PId = "1";
            cboAddGroup.Items.Add(group1);

            Group group2 = new Group();
            group2.PtName = "同事";
            group2.PId = "2";
            cboAddGroup.Items.Add(group2);

            Group group3 = new Group();
            group3.PtName = "同学";
            group3.PId = "3";
            cboAddGroup.Items.Add(group3);

            Group group4 = new Group();
            group4.PtName = "家人";
            group4.PId = "4";
            cboAddGroup.Items.Add(group4);
        }

        /// <summary>
        /// 增加新的数据行
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnAdd_Click(object sender, EventArgs e)
        {
            Group group = cboAddGroup.SelectedItem as Group;
            string sql = string.Format("insert into [PhoneNum](pTypeId, pName, pCellPhone, pHomePhone) values({0},'{1}','{2}','{3}')", group.PId, txtAddName.Text, txtAddPhoneNumber.Text, txtAddHomeNum.Text);
            GetMethod(sql);
        }

        /// <summary>
        /// 执行增删改数据库的方法
        /// </summary>
        /// <param name="sql">要执行的SQL语句</param>
        private void GetMethod(string sql)
        {
            using (SqlConnection conn = new SqlConnection(conStr))
            {
                using (SqlCommand cmd = new SqlCommand(sql, conn))
                {
                    conn.Open();
                    cmd.ExecuteNonQuery();
                    BindDgv();
                }
            }
        }

        /// <summary>
        /// 删除选中的数据行
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnDel_Click(object sender, EventArgs e)
        {
            int index = 0;
            string sql = string.Format("delete from [PhoneNum] where pId={0}",dgvPhoneBook[index,dgvPhoneBook.SelectedCells[0].RowIndex].Value);
            GetMethod(sql);
        }

        /// <summary>
        /// 修改选中的数据行
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnChange_Click(object sender, EventArgs e)
        {
            int index = 0;
            Group group = cboAddGroup.SelectedItem as Group;
            string sql = string.Format("update [PhoneNum] set pTypeId={0},pName='{1}',pCellPhone='{2}',pHomePhone='{3}' where pId={4}", group.PId, txtAddName.Text, txtAddPhoneNumber.Text, txtAddHomeNum.Text, dgvPhoneBook[index, dgvPhoneBook.SelectedCells[0].RowIndex].Value);
            GetMethod(sql);
        }

      

        
    }
}

代码写的比较乱，希望大家能看懂