Winform 交互数据库的规整操作

Winform 连接数据库 增删改查基本操作

新建文件夹 App_Code
添加两个类：
UserDA.cs(封装表中字段)
User.Data.cs（书写连接数据库，增删改查的操作方法）

　　

using WindowsFormsApplication7.App_Code;

namespace WindowsFormsApplication7
{
    public partial class Form4 : Form
    {
        public Form4()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Insert f = new Insert();
            f.Owner = this;
            f.Show();
        }

        private void Form4_Load(object sender, EventArgs e)
        {
            List<UserData> list = new UserDA().Select();
            Binddata(list);
        }

        private void Binddata(List<UserData> list)
        { 
            //第一步：构建listview"'
            listView1.Columns.Clear();
            listView1.Columns.Add("编号");
            listView1.Columns.Add("用户名");
            listView1.Columns.Add("密码");

            listView1.Items.Clear();

            //读取数据，通过数据构建listview中的行

            foreach (UserData data in list)
            {
                ListViewItem lt = new ListViewItem();
                lt.Text = data.Code.ToString();
                lt.SubItems.Add(data.Uname);
                lt.SubItems.Add(data.UPass);

                listView1.Items.Add(lt);
            }
        }

        private void button4_Click(object sender, EventArgs e)
        {
            List<UserData> listtiaojian =  new UserDA().Select(textBox1.Text);
            Binddata(listtiaojian);
        }

        private void button3_Click(object sender, EventArgs e)
        {
            if (listView1.SelectedItems.Count > 0)
            {
               string code = listView1.SelectedItems[0].Text;
               new UserDA().Delete(code);
                //重新绑定数据
               List<UserData> list = new UserDA().Select();
               Binddata(list);
            }
            else
            {
                MessageBox.Show("请选择，再删除");
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (listView1.SelectedItems.Count > 0)
            {
                UserData data = new UserData();
                data.Code = int.Parse(listView1.SelectedItems[0].SubItems[0].Text);
                data.Uname = listView1.SelectedItems[0].SubItems[1].Text;
                data.UPass = listView1.SelectedItems[0].SubItems[2].Text;
                Update f = new Update(data);
                f.Show();
            }
            else
            {
                MessageBox.Show("请选择，再修改");
            }

           
        }
    }
}

　　

App-code userdata.cs

namespace WindowsFormsApplication7.App_Code
{
    public class UserData
    {
        private int _Code;

        public int Code
        {
            get { return _Code; }
            set { _Code = value; }
        }
        private string _Uname;

        public string Uname
        {
            get { return _Uname; }
            set { _Uname = value; }
        }
        private string _UPass;

        public string UPass
        {
            get { return _UPass; }
            set { _UPass = value; }
        }
    }
}

　　

App_code   UserDA().cs

using System.Data.SqlClient;

namespace WindowsFormsApplication7.App_Code
{
    public class UserDA
    {
        private SqlConnection _Conn;
        private SqlCommand _Cmd;

        public UserDA()
        {
            _Conn = new SqlConnection("server=.;database=data1220;user=sa;pwd=");
        }

        //添加方法
        public void Insert(UserData data)
        {
            _Conn.Open();
            _Cmd = _Conn.CreateCommand();
            _Cmd.CommandText = "insert into users values(@uname,@upass)";
            _Cmd.Parameters.Clear();
            _Cmd.Parameters.Add("@uname",data.Uname);
            _Cmd.Parameters.Add("@upass", data.UPass);

            _Cmd.ExecuteNonQuery();
            _Conn.Close();
        }

        //查询方法
        public List<UserData> Select()
        {
            List<UserData> list = new List<UserData>();

            _Conn.Open();
            _Cmd = _Conn.CreateCommand();
            _Cmd.CommandText = "select *from users";
            SqlDataReader dr = _Cmd.ExecuteReader();
            while (dr.Read())
            {
                UserData data = new UserData();
                data.Code = int.Parse(dr["code"].ToString());
                data.Uname = dr["uname"].ToString();
                data.UPass = dr["upass"].ToString();

                list.Add(data);
            }

            return list;
        }

        /// <summary>
        /// 根据用户名查
        /// </summary>
        /// <returns></returns>
        public List<UserData> Select(string uname)
        {
            List<UserData> list = new List<UserData>();

            _Conn.Open();
            _Cmd = _Conn.CreateCommand();
            _Cmd.CommandText = "select *from users where uname like '%"+uname+"%'";
            SqlDataReader dr = _Cmd.ExecuteReader();
            while (dr.Read())
            {
                UserData data = new UserData();
                data.Code = int.Parse(dr["code"].ToString());
                data.Uname = dr["uname"].ToString();
                data.UPass = dr["upass"].ToString();

                list.Add(data);
            }

            return list;
        }

        public void Delete(string code)
        {
            _Conn.Open();
            _Cmd = _Conn.CreateCommand();
            _Cmd.CommandText = "delete from users where code="+code;
            _Cmd.ExecuteNonQuery();
            _Conn.Close();
        }


        public void update(UserData data)
        {
            _Conn.Open();
            _Cmd = _Conn.CreateCommand();
            _Cmd.CommandText = "update users set uname=@uname,upass=@upass where code=@code";
            _Cmd.Parameters.Clear();
            _Cmd.Parameters.Add("@code",data.Code);
            _Cmd.Parameters.Add("@uname",data.Uname);
            _Cmd.Parameters.Add("@upass",data.UPass);

            _Cmd.ExecuteNonQuery();
            _Conn.Close();
        }
    }
}