点击Ehlib列标题的快速排序方法

 Ehlib3.0以后的版本虽然支持排序功能，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。