How can I icrease the canvas of a transparent icon?

Question

I have some transparent icons smaller in size than the ImageList where I want to add them. I try to add them as usual with ImageList.AddIcon(IcoHandle); but it seems they are scaled to the ImageList size. I want find a way to increase the canvas of my Icon with transparent color so it will be added in the ImageList without scaling. Is this possible ?

Update1:

I've done as David said, but the icon lost transparency...

 LoadIconWithScaleDown(HInstance, PChar('NUT_VITAL'), ISmall, ISmall, hI);
 Ico.Handle:= hI;

 Bmp:= TBitmap.Create;
 Bmp.Transparent:= True;
 Bmp.PixelFormat:= pf32bit;
 Bmp.SetSize(ISize, ISize);
 Bmp.Canvas.Draw(0, 0, Ico);
 Pics.Add(Bmp, nil);
 Bmp.Free;

Create a new image of the required size, and draw the smaller image onto it — David Heffernan, Jan 26 '20 at 22:25
Why are you creating a visual control (TImage) to copy the icon? That's totally inappropriate (and unnecessary). — Ken White, Jan 27 '20 at 13:46
Create a `TBitmap` in code instead, and use it in place of the `TImage`. A `TImage` control is for visually displaying an image to a user. — Ken White, Jan 27 '20 at 13:49

score 0 · Accepted Answer · edited Jan 28 '20 at 10:53

0

I finally figured it out... thanks to David, Ken and Torbins answer from here.

I had to set brush style to bsClear before setting the size of the bitmap. :)

LoadIconWithScaleDown(HInstance, PChar('NUT_VITAL'), ISmall, ISmall, hI);
Ico.Handle := hI;

Bmp := TBitmap.Create;
try
  Bmp.Canvas.Brush.Style := bsClear;
  Bmp.SetSize(ISize, ISize);
  N := (ISize - ISmall) div 2;
  Bmp.Canvas.Draw(N, N, Ico);
  Pics.Add(Bmp, nil);
finally
  Bmp.Free; 
end;

edited Jan 28 '20 at 10:53

Andreas Rejbrand

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answered Jan 27 '20 at 14:22

Marus Gradinaru

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Weird. Why don't you pass ISize to LoadIconWithScaleDown – David Heffernan Jan 27 '20 at 14:24
`ISize` is my image list size, but I want some icons to be samller than the usual size... – Marus Gradinaru Jan 27 '20 at 14:33
If you have the thing sitting in a resource, call LoadIconWithScaleDown as many times as you need to get it loaded at whichever size you need at that point in the code – David Heffernan Jan 27 '20 at 14:52
Yes, but I use those icons for some TButton, and they work with a ImageList. – Marus Gradinaru Jan 27 '20 at 16:04
There is nothing stopping you doing both. What you makes you think you can only call LoadIconWithScaleDown once? – David Heffernan Jan 27 '20 at 16:20
But I cannot load a image into a TButton, his image is set by `ImageIndex` property. – Marus Gradinaru Jan 27 '20 at 16:28
You can absolutely do this. But if you don't want to, fine. – David Heffernan Jan 27 '20 at 17:25
David, I don't know how, other than setting the `ImageIndex`... – Marus Gradinaru Jan 27 '20 at 17:46
You load the icon at the desired size and the add it to the image list. – David Heffernan Jan 27 '20 at 17:55

How can I icrease the canvas of a transparent icon?

1 Answers1