向DataGridView控件里插入行！

两个TEXTBOX,一个DATAGRIDVIEW。

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 WindowsFormsApplication59
{
    public partial class Form1 : Form
    {
        DataTable dt;
        int rowIndex = 0;

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            dt = new DataTable();
            dt.Columns.Add(" ");
            dt.Columns.Add("A");
            dt.Columns.Add("B");
            this.dataGridView1.DataSource = dt;

        }

        private void button1_Click(object sender, EventArgs e)
        {
            rowIndex++;
            DataRow dr = dt.NewRow();
            dr[0] = rowIndex;
            dr[1] = this.textBox1.Text;
            dr[2] = this.textBo