delphi下实现dbgrid导出多选的行的数据保存为Excel

procedure TPrint.SaveToExcel(DBGridTemp:TTechDBGrid20);
var
  ExcelApp:Variant;
  page:Variant;
  i,j,n:Integer;
  savedialog:TSaveDialog;
  BM:TBookmark;
  sFileName:string;
  HiFlag,LiFlag:Boolean;
  function IsFileInUse(fName : string) : boolean;
  var
     HFileRes : HFILE;
  begin
     Result := false; //返回值为假(即文件不被使用)
     if not FileExists(fName) then exit; //如果文件不存在则退出
     HFileRes := CreateFile(pchar(fName), GENERIC_READ or GENERIC_WRITE,
                 0 {this is the trick!}, nil, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
     Result := (HFileRes = INVALID_HANDLE_VALUE); //如果CreateFile返回失败那么Result为真(即文件正在被使用)
     if not Result then //如果CreateFile函数返回是成功
     CloseHandle(HFileRes);   //那么关闭句柄
  end;
begin
   if DBGridTemp.DataSource.DataSet.IsEmpty then //判断TDBGRID是否有数据
   begin
     Exit;
   end;
   
   SaveDialog := TSaveDialog.Create(nil);
   SaveDialog.Filter := 'Excel2000-Excel2003|*.xls|Excel2007|*.xlsx';
   SaveDialog.DefaultExt := '*.xls';