Draw a rid for easier referencing of Form size NewHeight := ((NewHeight div RowHeight) * RowHeight) + VerticalBorderHeight VerticalBorderHeight := Height - ClientHeight We use this to calculate needed vertivcal Form size to get certain Form ClientHeight Calculate number of pixels used for top and bottom Form border NewWidth := ((NewWidth div ColumnWidth) * ColumnWidth) + HorizontalBorderWidth HorizontalBorderWidth := Width - ClientWidth We use this to calculate needed horizontal Form size to get certain Form ClientWidth Calculate number of pixels used for left and right Form border Constants defining row anbd column dimensions Procedure TForm3.FormCanResize(Sender: TObject var NewWidth, It uses Forms OnCanResize notification event. So here is my example which is much easier and works perfectly. When I look at the code examples you tried all of them seem much more complicated that one I will present you. If i change the INC_SIZE to smaller or bigger i get the offset bug right away after resizing. I used ValueListEditor and if i set the INC_SIZE to DefaultRowHeight of the ValueListEditor, then there is no offset problem.īut it still shows the small portion of item below the current last visible row. Maybe scollbars and grid line width is making troubles here, dunno.

The less columns or rows then the bigger offset gets. Msg.WindowPos^.cy:=(Msg.WindowPos^.cy div 70)*70 Msg.WindowPos^.cx:=(Msg.WindowPos^.cx div 70)*70 If (Msg.WindowPos^.flags and SWP_NOSIZE = 0) and ((Msg.WindowPos^.cx Width)

Procedure TForm1.WMWindowPosChanging(var Msg: TWMWindowPosChanging)

Procedure WMWindowPosChanging (var Msg: TWMWindowPosMsg) message WM_WINDOWPOSCHANGING Make new project, drop a drawgrid to it, set its DefaultRowHeight to 64, DefaultColWidth to 64. Ok, found a way but after each 'snap' it has some offset more and more.

Delphi object inspector