type
TForm1 = class(TForm)
...
procedure CreateParams(var Params: TCreateParams); override;
end;
implementation
procedure TForm1.CreateParams(var Params: TCreateParams);
begin
inherited CreateParams(Params);
Params.ExStyle:=Ws_Ex_Traansparent;
end;
procedure TForm1.Create;
begin
Brush.Style:=bsClear;
end