Ehlib3.0版本以上虽然支持排序功能,但不支持带有Order By的SQL语句,而且排序很慢;我写的这个排序函数,利用ADO的sort方法,排序很快,几万条数据也是很快。该函数支持Lookup字段排序,不支持计算字段排序,因为计算字段值在内存里高速运算。排序分为:升序、降序和默认三种,支持排序图标。
procedure SortDBGridEh(Sender: TObject; ACol: Integer;
Column: TColumnEh); var FieldName, SortStr: string; begin Screen.Cursor := crSQLWait; try if (Sender is TDBGridEh) and ((Sender as TDBGridEh).DataSource.DataSet <> nil) then begin if not ((Sender as TDBGridEh).DataSource.DataSet is TCustomADODataSet) then Exit; if not (Sender as TDBGridEh).DataSource.DataSet.Active then
Exit; FieldName := Column.FieldName;
if (Sender as TDBGridEh).DataSource.DataSet.FindField(FieldName).IsBlob then Exit; if (Sender as TDBGridEh).DataSource.DataSet.FieldByName(FieldName).FieldKind =
fkData then SortStr := FieldName else if (Sender as TDBGridEh).DataSource.DataSet.FieldByName(FieldName).FieldKind = fkLookup then FieldName := (Sender as TDBGridEh).DataSource.DataSet.FieldByName(FieldName).KeyFields else FieldName := ''; if (FieldName = '') or (Pos(';', FieldName) > 0) then
Exit; case Column.Title.SortMarker of smNoneEh: begin Column.Title.SortMarker := smUpEh; TCustomADODataSet((Sender as TDBGridEh).DataSource.DataSet).Sort := FieldName; end;
smUpEh: begin Column.Title.SortMarker := smDownEh; TCustomADODataSet((Sender as TDBGridEh).DataSource.DataSet).Sort := FieldName + ' DESC'; end; smDownEh: begin Column.Title.SortMarker := smNoneEh; TCustomADODataSet((Sender as TDBGridEh).DataSource.DataSet).Sort := ''; end; end; end; finally Screen.Cursor := crDefault; end; end; --程序实现如下:
--在DBGridEh的事件OnTitleBtnClick引用该函数即可: procedure TFrmU_BasicSetup.dbgAddrCodeTitleBtnClick(Sender: TObject; ACol: Integer; Column: TColumnEh); begin SortDBGridEh(Sender, ACol, Column); end; --为了保证表格的每一列都能点击触发排序,你需要将你需要排序的列属性 -- Title->TitleButton设置为True。 |
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