//导出Excel的方法
  private void ExportExcel()
  {
   DataSet ds=dtsSelect;//数据源
   if(ds==null) return;

   string saveFileName="";
   bool fileSaved=false;
   SaveFileDialog saveDialog=new SaveFileDialog();
   saveDialog.DefaultExt ="xls";
   saveDialog.Filter="Excel文件|*.xls";
   saveDialog.FileName ="Sheet1";
   saveDialog.ShowDialog();
   saveFileName=saveDialog.FileName;
   if(saveFileName.IndexOf(":")<0) return; //被点了取消

   Excel.Application xlApp=new Excel.Application();

   if(xlApp==null)
   {
    MessageBox.Show("无法创建Excel对象，可能您的机子未安装Excel");
    return;
   }

   Excel.Workbooks workbooks=xlApp.Workbooks;
   Excel.Workbook workbook=workbooks.Add(Excel.XlWBATemplate.xlWBATWorksheet);
   Excel.Worksheet worksheet=(Excel.Worksheet)workbook.Worksheets[1];//取得sheet1
   //写入字段
   for(int i=0;i<ds.Tables[0].Columns.Count;i++)
   {
    worksheet.Cells[1,i+1]=ds.Tables[0].Columns[i].ColumnName;
   }
   //写入数值
   
   for(int r=0;r<ds.Tables[0].Rows.Count;r++)
   {
    for(int i=0;i<ds.Tables[0].Columns.Count;i++)
    {
     worksheet.Cells[r+2,i+1]=ds.Tables[0].Rows[r][i];
    }
    System.Windows.Forms.Application.DoEvents();
   }
   worksheet.Columns.EntireColumn.AutoFit();//列宽自适应。
   if(cmbxType.Text!="Notification")
   {
    Excel.Range rg=worksheet.get_Range(worksheet.Cells[2,2],worksheet.Cells[ds.Tables[0].Rows.Count+1,2]);
    rg.NumberFormat="00000000";
   }
   if(saveFileName!="")
   {
    try
    {
     workbook.Saved =true;
     workbook.SaveCopyAs(saveFileName);
     fileSaved=true;
    }
    catch(Exception ex)
    {
     fileSaved=false;
     MessageBox.Show("导出文件时出错,文件可能正被打开！\n"+ex.Message);
    }
   }
   else
   {
    fileSaved=false;
   }
   xlApp.Quit();
   GC.Collect();//强行销毁
   if(fileSaved && System.IO.File.Exists(saveFileName)) System.Diagnostics.Process.Start(saveFileName); //打开EXCEL
  }