Author: Tomas Rutkauskas

Set minimum/maximum values for a resizable form

Answer:

There is a windows message that requests the minimum and the maximum value for a
resizable window ('form').
The following code makes sure that a window of type TForm1 is not smaller than
100x100 and not larger than 200x200 pixels:

1   type
2     TForm1 = class(TForm)
3     protected
4       procedure WMGetMinMaxInfo(var message: TWMGetMinMaxInfo);
5         message WM_GETMINMAXINFO;
6     end;
7   
8   procedure TForm1.WMGetMinMaxInfo(var message: TWMGetMinMaxInfo);
9   begin
10    with message.MinMaxInfo^ do
11    begin
12      ptMinTrackSize := Point(100, 100);
13      ptMaxTrackSize := Point(200, 200);
14    end;
15  end;