Set the Forms BorderStyle to bsNone and BorderIcons.biSystemMenu to false. Put a Button on the Form.
Then try this code out. Amazing!
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls;
type
TForm1 = class(TForm)
Button1: TButton;
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.DFM}
procedure TForm1.FormCreate(Sender: TObject);
var
FullRgn, ClientRgn, ButtonRgn: THandle;
Margin, X, Y: Integer;
begin
Margin := (Width - ClientWidth) div 2;
FullRgn := CreateRectRgn(0, 0, Width, Height);
X := Margin;
Y := Height - ClientHeight - Margin;
ClientRgn := CreateRectRgn
(X, Y, X + ClientWidth, Y + ClientHeight);
CombineRgn(FullRgn, FullRgn, ClientRgn, RGN_DIFF);
X := X + Button1.Left;
Y := Y + Button1.Top;
ButtonRgn := CreateRectRgn
(X, Y, X + Button1.Width, Y + Button1.Height);
CombineRgn(FullRgn, FullRgn, ButtonRgn, RGN_OR);
SetWindowRgn(Handle, FullRgn, True);
end;
end.