private bool creatExcel(string xlsfile)
    {
      try
      {
        object missing = System.Reflection.Missing.Value;
        Excel.ApplicationClass myExcel = new Excel.ApplicationClass();

        Excel._Workbook xBk;        //工作薄 
        Excel._Worksheet xSt;   //工作Sheet  

        xBk = myExcel.Workbooks.Add(true);

        for (int i = 0; i < 1; i++)
        {
          xSt = (Excel._Worksheet)xBk.ActiveSheet;
          xSt.Name = "Sheet" + i;
          myExcel.Sheets.Add(missing, missing, 1, Excel.XlSheetType.xlWorksheet);
        }
        //myExcel.Visible = true;
        if (xlsfile.ToLower().EndsWith(".xlsx"))
        {
          xBk.SaveAs(xlsfile, 56, missing,
          missing, missing, missing, Excel.XlSaveAsAccessMode.xlShared,
          missing, missing, missing, missing, missing);
        }
        else
        {
          xBk.SaveAs(xlsfile, missing, missing,
          missing, missing, missing, Excel.XlSaveAsAccessMode.xlShared,
          missing, missing, missing, missing, missing);
        }
        myExcel.Quit();
        return true;
      }
      catch (Exception ex)
      {
        MessageBox.Show("Excel创建失败!原因:" + ex.Message);
        return false;
      }
    }