C#------CURD

namespace CURD
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void toolStripButton1_Click(object sender, EventArgs e)
        {
            //新增
            PersonEdit form = new PersonEdit();
            form.Action = "AddNew";
            form.ShowDialog();
            LoadData();//新增完成，刷新界面
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            //禁止自动生成列
            gridePersons.AutoGenerateColumns = false;

            //查询数据
            LoadData();
        }

        private void LoadData()
        {
            DataTable tab = MySqlHelper.ExecuteQuery("select id,name,age,if(gender,‘男‘,‘女‘) gender from t_persons");
            gridePersons.DataSource = tab;
        }

        private void gridePersons_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {

            DataTable tab = (DataTable)gridePersons.DataSource;
            //得到选中的行数
            DataRow row = tab.Rows[e.RowIndex];
            //得到当前选中行的ID号
            int id = (int)row["id"];

            //点击的是哪一列
            if (e.ColumnIndex == 0)//编辑
            {
                PersonEdit form = new PersonEdit();
                form.Action = "Edit";
                form.EditingId = id;
                form.ShowDialog();
                LoadData();
            }
            else if (e.ColumnIndex == 1)//删除
            {
               

                //提示用户是否要删除
                if (MessageBox.Show("你真的要删除吗？", "提示",
                    MessageBoxButtons.YesNo, MessageBoxIcon.Question) != DialogResult.Yes)
                {
                    return;
                }

                //根据ID删除
                MySqlHelper.ExecuteNonQuery("DELETE FROM t_persons WHERE id = @id",
                    new MySqlParameter { ParameterName = "@id", Value = id });

                //刷新数据
                LoadData();
            }
        }

        private void shuaxin_Click(object sender, EventArgs e)
        {
            LoadData();
        }

    }
}

using MySql.Data.MySqlClient;
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 CURD
{
    public partial class PersonEdit : Form
    {
        //新增数据传递 Action="AddNew"
        public string Action { get; set; }
        //编辑数据传递 Action = "Edit" EditingId=5
        public int EditingId { get; set; }

        public PersonEdit()
        {
            InitializeComponent();
        }

        private void PersonEdit_Load(object sender, EventArgs e)
        {
            if (Action == "Edit")//如果是编辑，则先加载旧的数据
            {
               DataTable table = MySqlHelper.ExecuteQuery("select * from t_persons where id=@id",
                    new MySqlParameter { ParameterName="@id",Value=EditingId});

               if (table.Rows.Count <= 0)
               {
                   MessageBox.Show("找不到ID为"+EditingId+"的数据");
                   return;
               }
                //取得查询出来的数据
               DataRow row = table.Rows[0];
               txtName.Text = (string)row["name"];
               txtAge.Text = (string)row["age"];
               int gender = (int)row["gender"];
               //判断是男还是女，男为第一列0 女为第二列1
                txtGender.SelectedIndex = (gender==1?0:1);
            }
        }
    }
}