{ Прозрачная
форма }
constructor TForm1.Create(AOwner:
TComponent);
begin
inherited;
// убираем сколлбары,
чтобы не мешались
// при изменении размеров
формы
HorzScrollBar.Visible:=
False;
VertScrollBar.Visible:= False;
// строим новый
регион
RebuildWindowRgn;
end;

procedure
TForm1.Resize;
begin
inherited;
// строим новый
регион
RebuildWindowRgn;
end;

procedure
TForm1.RebuildWindowRgn;
var
FullRgn, Rgn:
THandle;
ClientX, ClientY, I: Integer;
begin
//
определяем относительные координаты клиенской
части
ClientX:= (Width - ClientWidth) div 2;
ClientY:=
Height - ClientHeight - ClientX;
// создаем регион для всей
формы
FullRgn:= CreateRectRgn(0, 0, Width, Height);
//
создаем регион для клиентской части формы
// и вычитаем его
из FullRgn
Rgn:= CreateRectRgn(ClientX, ClientY, ClientX +
ClientWidth, ClientY
+
ClientHeight);
CombineRgn(FullRgn, FullRgn, Rgn,
rgn_Diff);
// теперь добавляем к FullRgn регионы каждого
контрольного элемента
for I:= 0 to ControlCount -1
do
with Controls[I] do begin
Rgn:= CreateRectRgn(ClientX
+ Left, ClientY + Top, ClientX + Left +
Width, ClientY +
Top + Height);
CombineRgn(FullRgn, FullRgn, Rgn,
rgn_Or);
end;
// устанавливаем новый регион
окна
SetWindowRgn(Handle, FullRgn,
True);
end;
end.

face=Verdana size=3>А как Вам понравится эта форма
?

unit
rgnu;
interface
uses
Windows, Messages, SysUtils,
Classes, Graphics, Controls, Forms, Dialogs,
Buttons,
Menus;

type
TForm1 =
class(TForm)
procedure FormCreate(Sender:
TObject);
procedure Button1Click(Sender:
TObject);
procedure FormPaint(Sender:
TObject);
private
{ Private declarations }
rTitleBar
: THandle;
Center : TPoint;
CapY : Integer;
Circum :
Double;
SB1 : TSpeedButton;
RL, RR :
Double;
procedure TitleBar(Act : Boolean);
procedure
WMNCHITTEST(var Msg: TWMNCHitTest);
message
WM_NCHITTEST;
procedure WMNCACTIVATE(var Msg:
TWMNCACTIVATE);
message WM_NCACTIVATE;
procedure
WMSetText(var Msg: TWMSetText);
message
WM_SETTEXT;
end;

var
Form1:
TForm1;

size=2>implementation

{$R
*.DFM}

size=2>CONST
TitlColors : ARRAY[Boolean] OF TColor
=
(clInactiveCaption, clActiveCaption);
TxtColors :
ARRAY[Boolean] OF TColor =
(clInactiveCaptionText,
clCaptionText);

procedure
TForm1.FormCreate(Sender: TObject);
VAR
rTemp, rTemp2 :
THandle;
Vertices : ARRAY[0..2] OF TPoint;
X, Y :
INteger;
begin
Caption := 'OOOH!
Doughnuts!';
BorderStyle := bsNone; {required}
IF Width
> Height THEN Width := Height
ELSE Height := Width;
{harder to calc if width <> height}
Center :=
Point(Width DIV 2, Height DIV 2);
CapY :=
GetSystemMetrics(SM_CYCAPTION)+8;
rTemp :=
CreateEllipticRgn(0, 0, Width, Height);
rTemp2 :=
CreateEllipticRgn((Width DIV 4), (Height DIV 4),
3*(Width
DIV 4), 3*(Height DIV 4));
CombineRgn(rTemp, rTemp, rTemp2,
RGN_DIFF);
SetWindowRgn(Handle, rTemp,
True);
DeleteObject(rTemp2);
rTitleBar :=
CreateEllipticRgn(4, 4, Width-4, Height-4);
rTemp :=
CreateEllipticRgn(CapY, CapY, Width-CapY,
Height-CapY);
CombineRgn(rTitleBar, rTitleBar, rTemp,
RGN_DIFF);
Vertices[0] := Point(0,0);
Vertices[1] :=
Point(Width, 0);
Vertices[2] := Point(Width DIV 2, Height
DIV 2);
rTemp := CreatePolygonRgn(Vertices, 3,
ALTERNATE);
CombineRgn(rTitleBar, rTitleBar, rTemp,
RGN_AND);
DeleteObject(rTemp);
RL := ArcTan(Width /
Height);
RR := -RL + (22 / Center.X);
X :=
Center.X-Round((Center.X-1-(CapY DIV 2))*Sin(RR));
Y :=
Center.Y-Round((Center.Y-1-(CapY DIV 2))*Cos(RR));
SB1 :=
TSpeedButton.Create(Self);
WITH SB1 DO
BEGIN
Parent
:= Self;
Left := X;
Top := Y;
Width := 14;
Height
:= 14;
OnClick := Button1Click;
Caption :=
'X';
Font.Style := [fsBold];
END;
end;

procedure
TForm1.Button1Click(Sender:
TObject);
begin
Close;
End;

procedure
TForm1.WMNCHITTEST(var Msg:
TWMNCHitTest);
begin
Inherited;
WITH Msg DO
WITH
ScreenToClient(Point(XPos,YPos)) DO
IF
PtInRegion(rTitleBar, X, Y) AND
(NOT
PtInRect(SB1.BoundsRect, Point(X,Y))) THEN
Result :=
htCaption;
end;

procedure
TForm1.WMNCActivate(var Msg:
TWMncActivate);
begin
Inherited;
TitleBar(Msg.Active);
end;

procedure
TForm1.WMSetText(var Msg:
TWMSetText);
begin
Inherited;
TitleBar(Active);
end;

procedure
TForm1.TitleBar(Act: Boolean);
VAR
TF : TLogFont;
R :
Double;
N, X, Y : Integer;
begin
IF Center.X = 0 THEN
Exit;
WITH Canvas DO
begin
Brush.Style :=
bsSolid;
Brush.Color :=
TitlColors[Act];
PaintRgn(Handle, rTitleBar);
R :=
RL;
Brush.Color := TitlColors[Act];
Font.Name :=
'Arial';
Font.Size := 12;
Font.Color :=
TxtColors[Act];
Font.Style :=
[fsBold];
GetObject(Font.Handle, SizeOf(TLogFont),
@TF);
FOR N := 1 TO Length(Caption) DO
BEGIN
X :=
Center.X-Round((Center.X-6)*Sin(R));
Y :=
Center.Y-Round((Center.Y-6)*Cos(R));
TF.lfEscapement :=
Round(R * 1800 / pi);
Font.Handle :=
CreateFontIndirect(TF);
TextOut(X, Y, Caption[N]);
R :=
R - (((TextWidth(Caption[N]))+2) / Center.X);
IF R < RR
THEN Break;
END;
Font.Name := 'MS Sans
Serif';
Font.Size := 8;
Font.Color :=
clWindowText;
Font.Style := [];
end;
end;

procedure
TForm1.FormPaint(Sender: TObject);
begin
WITH Canvas
DO
BEGIN
Pen.Color := clBlack;
Brush.Style :=
bsClear;
Pen.Width := 1;
Pen.Color := clWhite;
Arc(1,
1, Width-1, Height-1, Width, 0, 0, Height);
Arc((Width DIV
4)-1, (Height DIV 4)-1,
3*(Width DIV 4)+1, 3*(Height DIV
4)+1, 0, Height, Width, 0);
Pen.Color := clBlack;
Arc(1,
1, Width-1, Height-1, 0, Height, Width, 0);
Arc((Width DIV
4)-1, (Height DIV 4)-1,
3*(Width DIV 4)+1, 3*(Height DIV
4)+1, Width, 0, 0,
Height);
TitleBar(Active);
END;
end;

size=2>end.