Extract icon from execute, transparenty\mask problem
lazarus / 39-Graphics

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MaartenJB · 2013-02-28 07:43

Hi,

I've got some code to extract an icon from an execute. This works
okey, but the result is without transparenty\mask.

Is there a way to make this work?

Thanks


Code: [Select]uses ...., LCLType, ShellApi;

var
  LargeIco, SmallIco : hIcon;
  myIcon : TIcon;
begin
  if ExtractIconEx(PChar('C:\Windows\System32\notepad.exe'), 0,
LargeIco, SmallIco, 1) > null then begin

    myIcon := TIcon.Create;
    try
      myIcon.Handle := LargeIco;
      myIcon.Transparent := True;
      myIcon.SaveToFile('c:\temp\abc.ico');
    finally
      myIcon.Free;
    end;
  end;

end;

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BigChimp · 2013-02-28 08:28

Have no experience with this but just a hunch: don't you have to set a
certain pixel colour to mark transparency?

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MaartenJB · 2013-02-28 08:35

thanks for your hunch, but I think not, the icon contains a mask

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vrull · 2013-03-13 19:49

Just add
myIcon.Masked := true;

I tried your code as below and it worked fine
Code: [Select]...// top if the unit
type
  TForm1 = class(TForm)
    Image1: TImage;
    dlgOpen: TOpenDialog;
    procedure Image1DblClick(Sender: TObject);
  private
    { private declarations }
  public
    { public declarations }
  end;

var
  Form1: TForm1;

implementation
   uses LCLType, ShellApi;
{$R *.lfm}

{ TForm1 }

procedure TForm1.Image1DblClick(Sender: TObject);
var
  LargeIco, SmallIco : hIcon;
  myIcon : TIcon;
begin
  if dlgOpen.Execute then
    if ExtractIconEx(PChar(dlgOpen.FileName), 0, LargeIco, SmallIco,
1) > null then
      begin
        myIcon := TIcon.Create;
        try
          myIcon.Transparent := True;
          myIcon.Masked := True;
          myIcon.Handle := LargeIco;
          Image1.Picture.Icon.Assign(myIcon);
        finally
          myIcon.Free;
        end;
    end;
end;

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MaartenJB · 2013-03-14 09:08

Hi, Thanks for your reply.

I've tried that, the "masked" option does not change anything if I try
it. I've made a screenshot of the result I got, the left icon is the
one I extracted with an other application and the right one is
extracted with the code above.

so there is a big difference in icon quality, do you get a better
result?

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vrull · 2013-03-14 19:19

I've made some investigation and found that the problem is not in the
ExtractIconEx function, which works just fine, but in further
manipulation with the icon handler.
The attached project proves, that if one draws the icons straight away
their quality is not deteriorated (double-click on the second image).
So you should find the way to turn icon handle into something more
familiar without damaging the underlying image.

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MaartenJB · 2013-03-15 08:39

That's looking very promising. Thank you very much! 

So the problem is withing TIcon. I'll try to find a way to get around
it.