我添加模板列进行编辑、更新操作。可是当我修改完成点更新时，提示更新成功，但数据库中数据就是没有改。
    private void DataGrid4_UpdateCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
        {
            string ConnString = System.Configuration.ConfigurationSettings.AppSettings["case"];
            SqlConnection sqlcon = new SqlConnection(ConnString);

            //创建UPDATE命令字符串
            string updatecmd = "update Case_provisional set Num_regist=@Num_regist,Year_case = @Year_case where Num_regist = @Num_regist";
            SqlCommand MyCommand = new SqlCommand(updatecmd,sqlcon);

            MyCommand.Connection .Open();
MyCommand.Parameters .Add(new SqlParameter("@Num_regist",SqlDbType.Char,10));
            MyCommand.Parameters .Add(new SqlParameter("@Year_case",SqlDbType.Char,10));
TextBox txt1 = (TextBox)DataGrid4.Items[DataGrid4.EditItemIndex].Cells[2].FindControl("Year_case");
            TextBox txt2 = (TextBox)DataGrid4.Items[DataGrid4.EditItemIndex].Cells[3].FindControl("Name_court");
//取得主键索引的值
            MyCommand.Parameters["@Num_regist"].Value = DataGrid4.DataKeys[e.Item .ItemIndex];
            MyCommand.Parameters["@Year_case"].Value = txt1.Text.ToString();
MyCommand.ExecuteNonQuery();
                RegisterStartupScript("showSaveMessage","<script language='javascript'>alert('已更新记录!')</script>");

高手们，请帮帮忙啊！