一个很实用的Ehlib排序函数，适合ADO
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。