(Delphi)Excel的快速导入

//怎样可以提高EXCEL的导出速度？

function TForm1.ExportToExcel: Boolean;
var
xlApp,xlBook,xlSheet,xlQuery: Variant;
adoConnection,adoRecordset: Variant;
begin
adoConnection := CreateOleObject('ADODB.Connection');
adoRecordset := CreateOleObject('ADODB.Recordset');
adoConnection.Open(ADOConnectionString);
adoRecordset.CursorLocation := adUseClient;
adoRecordset.Open('SELECT * FROM tableName',adoConnection,1,3);

xlApp := CreateOleObject('Excel.Application');
xlBook := xlApp.Workbooks.Add;
xlSheet := xlBook.Worksheets['sheet1'];
xlApp.Visible := True;

//把查询结果导入EXCEL数据

xlQuery := xlSheet.QueryTables.Add(adoRecordset,xlSheet.Range['A1']); //关键是这一句
xlQuery.FieldNames := True;
xlQuery.RowNumbers := False;
xlQuery.FillAdjacentFormulas := False;
xlQuery.PreserveFormatting := True;
xlQuery.RefreshOnFileOpen := False;
xlQuery.BackgroundQuery := True;
//xlQuery.RefreshStyle := xlInsertDeleteCells;
xlQuery.SavePassword := True;
xlQuery.SaveData := True;
xlQuery.AdjustColumnWidth := True;
xlQuery.RefreshPeriod := 0;
xlQuery.PreserveColumnInfo := True;
xlQuery.FieldNames := True;
xlQuery.Refresh;