画选中的黑点
procedure WmNcHitTest(var Msg: TWmNcHitTest); message wm_NcHitTest;
procedure TCustomUicExControl.WmNcHitTest(var Msg: TWmNcHitTest);
var
Pt: TPoint;
i: Integer;
begin
if FSelected then
begin
Pt := Point (Msg.XPos, Msg.YPos);
Pt := ScreenToClient (Pt);
Msg.Result := 0;
for i := 1 to 8 do
if PtInRect (FRectList , Pt) then
Msg.Result := FPosList ;
if Msg.Result = 0 then
inherited;
end
else
inherited;
end;