VCL Delphi

Question:
How can I respond to the user minimizing or maximizing my form
before the resizing actually takes place?
Answer:
The following example demonstrates trapping the Windows
WM_SYSCOMMAND message. If the command specifies to minimize or
maximize the form, we will beep the PC speaker instead;
Example:
type
TForm1 = class(TForm)
private
{ Private declarations }
procedure WMSysCommand(var Msg: TWMSysCommand);
message WM_SYSCOMMAND;
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.DFM}
procedure TForm1.WMSysCommand;
begin
if (Msg.CmdType = SC_MINIMIZE) or
(Msg.CmdType = SC_MAXIMIZE) then
MessageBeep(0) else
inherited;
end;