Chapter 10. WinForm-DataGridView

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.SqlClient;

namespace 数据控件
{
    public class DataConnection
    {
        private static string connstr = "server=.; database=mydb; user=sa; pwd=ray;";
        public static SqlConnection Conn
        {
            get { return new SqlConnection(connstr); }
        }
    }
}

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

namespace 数据控件
{
    public class Info
    {
        private string code;

        public string Code
        {
            get { return code; }
            set { code = value; }
        }
        private string name;

        public string Name
        {
            get { return name; }
            set { name = value; }
        }
        private bool sex;

        public bool Sex
        {
            get { return sex; }
            set { sex = value; }
        }
        private string nation;

        public string Nation
        {
            get { return nation; }
            set { nation = value; }
        }
        private DateTime birthday;

        public DateTime Birthday
        {
            get { return birthday; }
            set { birthday = value; }
        }

        public string SexName
        {
            get { return this.sex ? "男" : "女"; }
        }

        public string NationName
        {
            get {
                NationData data = new NationData();
                return data.NationName(Nation);
            }
        }
        public string BirthdayStr
        {
            get { return this.Birthday.ToString("yyyy年MM月dd日"); }
        }
    }
}

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

namespace 数据控件
{
    public class Nation
    {
        private string code;

        public string Code
        {
            get { return code; }
            set { code = value; }
        }
        private string name;

        public string Name
        {
            get { return name; }
            set { name = value; }
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.SqlClient;

namespace 数据控件
{
    public class InfoData
    {
        private SqlConnection _conn;
        private SqlCommand _cmd;
        private SqlDataReader _dr;

        public InfoData()
        {
            _conn = DataConnection.Conn;
            _cmd = _conn.CreateCommand();
        }

        /// <summary>
        /// 查询Info表全部数据
        /// </summary>
        /// <returns></returns>
        public List<Info> Select()
        {
            _cmd.CommandText = "select *from Info";
            _conn.Open();
            _dr = _cmd.ExecuteReader();

            List<Info> list = new List<Info>();

            if (_dr.HasRows)
            {
                while (_dr.Read())
                {
                    Info data = new Info();

                    data.Code = _dr[0].ToString();
                    data.Name = _dr[1].ToString();
                    data.Sex = Convert.ToBoolean(_dr[2]);
                    data.Nation = _dr[3].ToString();
                    data.Birthday = Convert.ToDateTime(_dr[4]);

                    list.Add(data);
                }
            }
            _conn.Close();
            return list;
        }

        /// <summary>
        /// 删除Info表指定数据
        /// </summary>
        /// <param name="code">代号</param>
        public void Delete(string code)
        {
            _cmd.CommandText = "delete from Info where Code=@code";
            _cmd.Parameters.Clear();
            _cmd.Parameters.AddWithValue("@code",code);
            _conn.Open();
            _cmd.ExecuteNonQuery();
            _conn.Close();
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.SqlClient;

namespace 数据控件
{
    public class NationData
    {
        private SqlConnection _conn;
        private SqlCommand _cmd;
        private SqlDataReader _dr;

        public NationData()
        {
            _conn = DataConnection.Conn;
            _cmd = _conn.CreateCommand();
        }

        public string NationName(string code)
        {
            _cmd.CommandText = "select Name from Nation where Code=@code";
            _cmd.Parameters.AddWithValue("@code",code);
            _conn.Open();
            _dr = _cmd.ExecuteReader();
            if (_dr.HasRows)
            {
                _dr.Read();
                return _dr[0].ToString();
            }
            else { return null; }
            _conn.Close();
        }
    }
}

设计界面：

后台代码：

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 数据控件
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            InfoData da=new InfoData();
            
            //绑定数据源
            dataGridView1.DataSource = da.Select();

            //取消默认选中第一行
            dataGridView1.ClearSelection();  
        }

        private void button1_Click(object sender, EventArgs e)
        {
            //取出选中项的值
            if (dataGridView1.SelectedCells.Count > 0)
            {
                MessageBox.Show(dataGridView1.SelectedCells[0].Value.ToString());
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            //取出选中行绑定的对象
            Info data = dataGridView1.SelectedRows[0].DataBoundItem as Info;
            MessageBox.Show(data.Code + " " + data.Name + " " + data.SexName + " " + data.NationName + " " + data.BirthdayStr);
        }

        private void button3_Click(object sender, EventArgs e)
        {
            //删除选中项
            Info data = dataGridView1.SelectedRows[0].DataBoundItem as Info;
            InfoData da = new InfoData();
            da.Delete(data.Code);

            //刷新数据
            dataGridView1.DataSource = da.Select();
            dataGridView1.ClearSelection();
        }
    }
}

运行界面：

获取选定项：

获取选定行绑定对象：

删除：                              　　　　　　　　　　　　　　　　　　　　　　　　刷新：