datagridview单元格中输入一个值按下tab后判断该值是否存在数据库中

Question

在datagridview单元格中输入字符串 按下tab光标移到下一单元格 此时自动判断该字符串是否存在于sql数据库中，存在则messagebox show XXXX已存在，若不存在，无任何操作

Answer 1

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;

namespace Q692913
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            dataGridView1.Columns.Add("id", "NO.");
            dataGridView1.Columns.Add("name", "姓名");
            DataClasses1DataContext db = new DataClasses1DataContext();
            foreach (var item in db.Table1s)
            {
                dataGridView1.Rows.Add(new object[] { item.id, item.name });
            }
            dataGridView1.CellEndEdit += new DataGridViewCellEventHandler(dataGridView1_CellEndEdit);
        }

        private void dataGridView1_CellEndEdit(object sender, DataGridViewCellEventArgs e)
        {
            if (e.ColumnIndex == 1)
            {
                DataClasses1DataContext db = new DataClasses1DataContext();
                string name = dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Value.ToString();
                if (db.Table1s.Any(x => x.name == name))
                {
                    MessageBox.Show(name + " 已经存在!");
                }
            }
        }
    }
}