DataTable内容正常，Response.Flush()或者Response.End()后无文件输出到客户端？

Question

问题：Response.Flush()或者Response.End()后，客户端都无Excel文件输出到客户端
代码如下

protected void btnInput_Click(object sender, EventArgs e)
        {
            DataTable dt = Tower.BLL.ImportAndInput_BLL.DSelect_meter_BLL(ss);
            string strFileName = "电表信息导出表" + DateTime.Now.ToString("yyyyMMddHHmmss");
            ExportExcel(dt, strFileName, "电表信息导出表");

        }


                public void ExportExcel(DataTable dt, string strFileName, string strSheetName)
        {
            HSSFWorkbook book = new HSSFWorkbook();
            ISheet sheet = book.CreateSheet(strSheetName);

            IRow headerrow = sheet.CreateRow(0);
            ICellStyle style = book.CreateCellStyle();
            style.Alignment = HorizontalAlignment.Center;
            style.VerticalAlignment = VerticalAlignment.Center;

            HSSFRow dataRow = (HSSFRow)sheet.CreateRow(0);
            //导出文件列名
            string strColumns = "电表序号,电表编号,电表用户号";
            string[] strArry = strColumns.Split(',');
            for (int i = 0; i < strArry.Length; i++)
            {
                dataRow.CreateCell(i).SetCellValue(strArry[i]);
                dataRow.GetCell(i).CellStyle = style;
            }

            for (int i = 0; i < dt.Rows.Count; i++)
            {
                dataRow = (HSSFRow)sheet.CreateRow(i + 1);
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    string ValueType = "";
                    string Value = "";
                    if (dt.Rows[i][j].ToString() != null)
                    {
                        ValueType = dt.Rows[i][j].GetType().ToString();
                        Value = dt.Rows[i][j].ToString();
                    }
                    switch (ValueType)
                    {
                        case "System.String"://字符串类型
                            dataRow.CreateCell(j).SetCellValue(Value);
                            break;
                        case "System.DateTime"://日期类型
                            System.DateTime dateV;
                            System.DateTime.TryParse(Value, out dateV);
                            dateV.ToString("yy/mm/dd");
                            dataRow.CreateCell(j).SetCellValue(dateV);
                            //Value = DateTime.Parse(Value).ToString("d");
                            //dataRow.CreateCell(j).SetCellValue(Value);
                            break;

                        case "System.Boolean"://布尔型
                            bool boolV = false;
                            bool.TryParse(Value, out boolV);
                            dataRow.CreateCell(j).SetCellValue(boolV);
                            break;
                        case "System.Int16"://整型
                        case "System.Int32":
                        case "System.Int64":
                        case "System.Byte":
                            int intV = 0;
                            int.TryParse(Value, out intV);
                            dataRow.CreateCell(j).SetCellValue(intV);
                            break;
                        case "System.Decimal"://浮点型
                        case "System.Double":
                            double doubV = 0;
                            double.TryParse(Value, out doubV);
                            dataRow.CreateCell(j).SetCellValue(doubV);
                            break;
                        case "System.DBNull"://空值处理
                            dataRow.CreateCell(j).SetCellValue("");
                            break;
                        default:
                            dataRow.CreateCell(j).SetCellValue("");
                            break;
                    }
                    dataRow.GetCell(j).CellStyle = style;
                    //设置宽度
                    sheet.SetColumnWidth(j, (Value.Length + 10) * 256);
                }
            }

                MemoryStream ms = new MemoryStream();
                book.Write(ms);
                Response.AddHeader("Content-Disposition", string.Format("attachment; filename={0}.xls", HttpUtility.UrlEncode(strFileName, System.Text.Encoding.UTF8)));
                Response.BinaryWrite(ms.ToArray());
                book = null;
                ms.Close();
                Response.Flush();
                //Response.End();

        }