GridView导出中缺少TemplateField

Question

我能够将GridView导出到文本文档，但是当我打开文本文档时，GridView中的中间列数据丢失了，我相信这是因为它是一个TemplateField，而其他列是普通的BoundFields。我不确定如何在保留TemplateField的同时解决此问题，因为我需要保持这种状态。

这是导出方法背后的我的C＃代码

 protected void ExportTextFile(object sender, EventArgs e)
        {
            //the text file
            string sFileName = "Credit File-" + System.DateTime.Now.Date + ".txt";
            sFileName = sFileName.Replace("/", "");

            //send output to the client maching using response object
            Response.ClearContent();
            Response.Buffer = true;
            Response.AddHeader("content-disposition", "attachment; filename=" + sFileName);
            Response.ContentType = "application/text";
            EnableViewState = false;

            StringBuilder objSB = new StringBuilder();
            int iCol = 0; //counter for columns
            int iRow = 0; //counter for rows
         
            
            for (iCol = 0; iCol < GridView4.Columns.Count; iCol++)
            {
                objSB.Append(GridView4.Columns[iCol].HeaderText + ',');
            }

            objSB.Append(Environment.NewLine);

            for (iRow = 0; iRow < GridView4.Rows.Count; iRow++)
            {
                for (iCol = 0; iCol < GridView4.Columns.Count; iCol++)
                {
                    objSB.Append(GridView4.Rows[iRow].Cells[iCol].Text + ',');
                }

                objSB.Append(Environment.NewLine);
            }

            Response.Write(objSB.ToString());
            Response.End();
        }