单击DBGRID网格标题排序

单击网格标题排序 

procedure TForm1.GridTitleSort(Column: TColumn);
var s,cFieldName:string;
 i:integer;
 DataSet:TDataSet;
 procedure setTitle;
 var ii:integer;
     cStr:string;
     c:TColumn;
 begin
   for ii:=0 to TDBGrid(Column.Grid).Columns.Count-1 do
   begin
     c:=TDBGrid(Column.Grid).Columns[ii];
     cStr:=c.Title.Caption;
     if (pos('▲',cStr)=1) or (pos('▼',cStr)=1) then
      begin
      Delete(cStr,1,2);
      c.Title.Caption:=cStr;
      end;
   end;

 end;
begin
setTitle;
DataSet:=Column.Grid.DataSource.DataSet;
if Column.Field.FieldKind=fkLookup then
 cFieldName:=Column.Field.KeyFields
else if Column.Field.FieldKind=fkCalculated then
 cFieldName:=Column.Field.KeyFields
else
 cFieldName:=Column.FieldName;
//=================================AdoDataSet=====================

if DataSet is TCustomADODataSet then begin
 s:=TCustomADODataSet(DataSet).Sort;
 if s='' then begin
   s:=cFieldName;
   Column.Title.Caption:='▲'+Column.Title.Caption;
 end
 else begin
   if Pos(cFieldName,s)<>0 then begin
     i:=Pos('DESC',s);
     if i<=0 then begin
       s:=s+' DESC';
       Column.Title.Caption:='▼'+Column.Title.Caption;
     end
     else begin
       Column.Title.Caption:='▲'+Column.Title.Caption;
       Delete(s,i,4);
     end;
   end
   else begin
     s:=cFieldName;
     Column.Title.Caption:='▲'+Column.Title.Caption;
   end;
 end;
 TCustomADODataSet(DataSet).Sort:=s;
end
//============================Clientdataset==========================
else if DataSet is TClientDataSet then begin
 if TClientDataSet(DataSet).indexfieldnames<>'' then
 begin
   i:=TClientDataSet(DataSet).IndexDefs.IndexOf('i'+Column.FieldName);
   if i=-1 then
   begin
     with TClientDataSet(DataSet).IndexDefs.AddIndexDef do
     begin
       Name:='i'+Column.FieldName;
       Fields:=Column.FieldName;
       DescFields:=Column.FieldName;
     end;
   end;
   TClientDataSet(DataSet).IndexFieldNames:='';
   TClientDataSet(DataSet).IndexName:='i'+Column.FieldName;
   Column.Title.Caption:='▼'+Column.Title.Caption;
 end
 else
 begin
   TClientDataSet(DataSet).IndexName:='';
   TClientDataSet(DataSet).IndexFieldNames:=column.fieldname;
   Column.Title.Caption:='▲'+Column.Title.Caption;
 end;
end;
end;