unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TForm1 = class(TForm) Button1: TButton; Button2: TButton; procedure Button1Click(Sender: TObject); procedure Button2Click(Sender: TObject); private FullRgn, ClientRgn, CtlRgn: THandle; procedure MakeTransparent; procedure UndoTransparent; public { Public declarations } end; var Form1: TForm1; implementation {$R *.dfm} procedure TForm1.MakeTransparent; var AControl: TControl; A, Margin, X, Y, CtlX, CtlY: 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); for A := 0 to ControlCount - 1 do begin AControl := Controls[A]; if (AControl is TWinControl) or (AControl is TGraphicControl) then with AControl do begin if Visible then begin CtlX := X + Left; CtlY := Y + Top; CtlRgn := CreateRectRgn(CtlX, CtlY, CtlX + Width, CtlY + Height); CombineRgn(FullRgn, FullRgn, CtlRgn, RGN_OR); end; end; end; SetWindowRgn(Handle, FullRgn, True); end; procedure TForm1.UndoTransparent; begin FullRgn := CreateRectRgn(0, 0, Width, Height); CombineRgn(FullRgn, FullRgn, FullRgn, RGN_COPY); SetWindowRgn(Handle, FullRgn, True); end; procedure TForm1.Button1Click(Sender: TObject); begin MakeTransparent; end; procedure TForm1.Button2Click(Sender: TObject); begin UndoTransparent; end; end.
Saludos.