DataGrid删除对话框 ＆ 限制编辑模式TextBox长度

private void DataGrid1_ItemDataBound(object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)
  {  
   ////进入编辑模试限制TextBox的width////
   
   e.Item.Cells[4].Attributes.Add("onClick","return confirm('你确定要删除这一项吗？');");

   if(e.Item.ItemType == ListItemType.EditItem)
    {   
     if(e.Item.Controls[1].Controls[0].GetType().ToString() == "System.Web.UI.WebControls.TextBox")
     {
      TextBox tb = (TextBox)e.Item.Controls[1].Controls[0];
      tb.Width   = Unit.Parse("80px");
      tb.CssClass = "textbox";
      tb.Text    = Server.HtmlDecode(tb.Text);
     }     
     if(e.Item.Controls[2].Controls[0].GetType().ToString() == "System.Web.UI.WebControls.TextBox")
     {
      TextBox tb = (TextBox)e.Item.Controls[2].Controls[0];       
      tb.Width   = Unit.Parse("250px");
      tb.CssClass = "textbox";
      tb.Text    = Server.HtmlDecode(tb.Text);
     }     
    }
  }