DataGripView问题

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using Main.Bean;
using Main.Dao;namespace Main.View
{
    public partial class frmOrderManage : Form
    {
        public frmOrderManage()
        {
            InitializeComponent();
        }        #region 声明对象        OrderDao _orderDao = null;        StoneDao _stoneDao = null;        #endregion        private void frmOrderManage_Load(object sender, EventArgs e)
        {
            this._orderDao = new OrderDao();
            this._stoneDao = new StoneDao();
            InitOrder();
          
        }        /// <summary>
        /// 初始化表格
        /// </summary>
        private void InitOrder()
        {
            this.dgvOrder.DataSource = this._orderDao.SelOrderList();            if (this.dgvOrder.Rows.Count != 0)
            {
                this.dgvOrder.Columns.Add("stoneList","品名");
            }
            button1_Click(null,null);
        }        private void button1_Click(object sender, EventArgs e)
        {
            //这段代码放到InitOrder()方法的下面数据不能显示到表格，放这里却可以！
              //InitOrder()方法里面调用这个方法也不行，为什么？            for (int i = 0; i < this.dgvOrder.Rows.Count; i++)
            {
                this.dgvOrder.Columns["添加时间"].Width = 140;
                int id = int.Parse(this.dgvOrder.Rows[i].Cells["编号"].Value.ToString());
                string stoneList = _stoneDao.ToStoneList("OrderT", id);
                this.dgvOrder.Rows[i].Cells["stoneList"].Value = stoneList;
            }
        }
    }
}