Overlay icons in Windows

Question

How to overlay an icon over a folder or a file icon. For eg. the way Tortoise SVN, Dropbox etc. put a tick mark over a file icon and a folder icon? How to do it programmatically, for eg. from VB.Net .

Answer 1

You need to write a Shell Icon Overlay Handler.

Answer 2

Be advised that overlay icons are a tightly limited resource, which is why the various Tortoise extensions now share overlays. According to "The overlay icons appear, but not all of them" in the TortoiseSVN FAQ, there can only be 15 overlay icons in total, and 4 of these are already used by Windows.

If you would actually be happy using the same icons as Tortoise*, you too should use TortoiseOverlays. For details on how to do this, see TortoiseOverlays/Documentation.txt in the TortoiseSVN tree.