急 C#DataTable导出成Execl 总是提示object未包含"get_Range"的定义
各位高手请帮帮忙，在下面红色区域总是提示：object未包含"get_Range"的定义，导致导出数据失败
 try
  {
  System.Data.DataTable objDtResult = new System.Data.DataTable();
  objDtResult.Columns.Add("姓名");
  objDtResult.Columns.Add("性别");
  objDtResult.Columns.Add("年龄");
  objDtResult.Columns.Add("身份证号");

  objDtResult.Columns.Add("职业工种");

  objDtResult.Columns.Add("工作单位");

  objDtResult.Columns.Add("套餐名称");

  objDtResult.Columns.Add("企业分组");

  //指定数据源
  string m_strSerName = string.Empty;//套餐名
  string m_strGroup = string.Empty;//分组名
  string m_strSex = "男,女";
  string m_strEnterprise = this.m_objViewer.m_dgvEnterpriseDetail.Rows[0].Cells["entname_vchr"].Value.ToString();
  for (int intI = 0; intI < this.m_objViewer.m_dgvEnterpriseDetail.Rows.Count; intI++)
  {
  if (intI == 0)
  {
  m_strSerName = this.m_objViewer.m_dgvEnterpriseDetail.Rows[intI].Cells["sername_vchr"].Value.ToString();
  m_strGroup = this.m_objViewer.m_dgvEnterpriseDetail.Rows[intI].Cells["entgroupname_vchr"].Value.ToString();
  }
  else
  {
  m_strSerName += "," + this.m_objViewer.m_dgvEnterpriseDetail.Rows[intI].Cells["sername_vchr"].Value.ToString();
  m_strGroup += "," + this.m_objViewer.m_dgvEnterpriseDetail.Rows[intI].Cells["entgroupname_vchr"].Value.ToString();
  }
  }
  string saveFileName = "";
  SaveFileDialog saveDialog = new SaveFileDialog();
  saveDialog.DefaultExt = "xls";
  saveDialog.Filter = "Excel文件|*.xls";
  saveDialog.FileName = "";
  saveDialog.ShowDialog();
  saveFileName = saveDialog.FileName;
  if (saveFileName.IndexOf(":") < 0) return; //被点了取消 
  Microsoft.Office.Interop.Excel.Application xlApp = new Microsoft.Office.Interop.Excel.Application();
  if (xlApp == null)
  {
  MessageBox.Show("无法创建Excel对象，可能您的电脑未安装Excel");
  return;
  }

  Microsoft.Office.Interop.Excel.Workbooks workbooks = xlApp.Workbooks;
  Microsoft.Office.Interop.Excel.Workbook workbook = workbooks.Add(Microsoft.Office.Interop.Excel.XlWBATemplate.xlWBATWorksheet);
  Microsoft.Office.Interop.Excel.Worksheet worksheet = (Microsoft.Office.Interop.Excel.Worksheet)workbook.Worksheets[1];//取得sheet1 

  //新方法
  iCare.Pub.Utility.clsExcelExporter m_objExcelExporter = new Pub.Utility.clsExcelExporter();
  m_objExcelExporter.m_mthExport(saveFileName);

  //写入标题
  for (int i = 0; i < objDtResult.Columns.Count; i++) 
  {