Problem changing icon in Delphi 2007

Question

I've been working with a program someone else has made and I wanted to change the icon.

The icon I have is 256x256. I used http://converticon.com/ to create the icon (from a bmp I think). I used the icon in Inno Setup to create an installer and it worked fine

So I go to Options -> Application and attempt to load it. However, Delphi 2007 gives me an error 'The parameter is incorrect.' with this info: http://i.stack.imgur.com/vRCgs.png

When I do the same thing in Delphi XE, it works and loads the icon and changes it on compile. I can't use XE right now because the program uses a math parser that has a problem with unicode (thats something to fix for later haha)

So, what I did was open the project in XE, change the icon, save it, delete the dproj and open it in 2007. This works, compiles and displays the correct icon, but when I go to the project options, it gives me the same 'The parameter is incorrect' error.

The workaround isn't a big deal, but I shouldn't need to do it. Does anyone know why I can't change the icon in Delphi 2007?

Edit: I just used that same converticon site to convert the 256x256 icon to 192x192 and smaller and now it works perfectly. Thanks for the answers

Answer 1

The "icon" file is actually a collection of images, at different resolution and using different encodings. When I'm creating my icons I'm making sure they don't actually contain the 256x256 PNG-encoded version because development tools built before Windows Vista don't understand that. And that includes your Delphi 2007 and my Delphi 7. I also remove the alpha-encoded 256x256 icon because it simply makes the file needlessly large.

You've got two fixes possible:

• Find an ICO editor and remove all of the larger formats until your Delphi accepts the icon. I personally never seen the 256x256 used in the real world, they'd take up huge amounts of space on user's Desktop or in Windows Explorer.
• Use a dummy icon and replace the icon resource in the generated exe after Delphi is done with it. This way you can keep all of the larger image formats, including the 256x256 PNG image.

---

Edit to correct an error

If possible, always include the 256x256 image, Windows scales that down for everything above 64x64.

I always assumed Windows Explorer would show an image that's based on the closest matching image size available in the ICO. That is, if a 128x128 image is necessary, Windows would use the 128x128 image if available, or scale down the 256x256 image if that's available, or scale up the 96x96 image. Apparently that's not so. I've just made a test icon consisting of several image formats, including 32, 48, 72, 96, 128 and 256 consisting of simple blobs of color (using the flood-fill tool). In Windows Explorer I cycled throw the various Display Modes, and it became apparent that starting with "Large Icon" (and that's not very large) Windows will scale down the 256x256 icon, and if that's not available, use the 48x48 icon, unscaled! The result is truly ugly and unexpected. The 72x72, 96x96 and 128x128 icons were simply ignored.

Thank you David for pointing this out.

Answer 2

Older versions of Delphi don't support 256px Vista icons. I believe that 2010 does not support them so I guess the limitation was fixed in XE.

When working with an older Delphi you'll need to keep the 256px icon out of the IDE. You can still build an executable with a 256px icon from the command line compiler - I used to do just this before upgrading from Delphi 6. But to do this requires the use of a competent resource compiler, for example the Microsoft one.