whats new ¦  programming tips ¦  indy articles ¦  intraweb articles ¦  informations ¦  links ¦  interviews
 misc ¦  tutorials ¦  Add&Win Game

Tips (1541)

Database (90)
Files (137)
Forms (107)
Graphic (114)
IDE (21)
Indy (5)
Internet / LAN (130)
IntraWeb (0)
Math (76)
Misc (126)
Multimedia (45)
Objects/
ActiveX (51)

OpenTools API (3)
Printing (35)
Strings (83)
System (266)
VCL (242)

Top15

Tips sort by
component


Search Tip

Add new Tip

Add&Win Game

Advertising

28 Visitors Online


 
...Create a transparent TForm?
Autor: Mohammad Khorsandy
[ Print tip ]  

Tip Rating (9):  
     


  private
    
{ Private declarations }
    
FullRgn, ClientRgn, CtlRgn: THandle;
    procedure MakeTransparent;
    procedure UndoTransparent;
  end;

{...}

implementation

{...}

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;

// Test it:

procedure TForm1.Button1Click(Sender: TObject);
begin
  
MakeTransparent
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  
UndoTransparent
end;

 

Rate this tip:

poor
very good


Copyright © by SwissDelphiCenter.ch
All trademarks are the sole property of their respective owners