Thanks for the link. Glancing at it, I still don't see where there's a need to patch system controls for high DPI support, though. The closest thing I see there is for changing their fonts, but that seems different from patching them (no superclassing that I can see, etc.). Moreover, it's for dynamic DPI support (i.e. supporting DPI changes), not high DPI support. Is that what you were referring to?
That's not exactly a... helpful answer. In fact I already have a Win32 (dialog-based, if that makes any difference) one that looks just fine on 200% DPI on Windows 10. All it required handling was scaling the obvious stuff (icon sizes, overall window size, etc.) and the manifest, nothing that required superclassing or otherwise patching common controls. i.e. I just haven't run into the problem you're mentioning. I'm kind of confused why you linked to an article that doesn't support your claim either. Hence why I'm asking you instead of spending hours trying to reproduce what you're saying.
I didn't assume you'd give a helpful answer, but I didn't expect you to give that kind of an answer, either. You're always welcome not to respond if this is taking too much of your time. I figured maybe at least one of us would learn something about high DPI issues, hence why I engaged.
This is most definitely the default combo box. In fact, I just tried the version without visual styles as well, and that one looks fine under high DPI too (see screenshot). At this point I'm very confused what you are doing. Perhaps you're not on Windows 10?
dataflow: That is indeed a nice looking combobox in your new screenshot. I'm not getting that result on win10 when using the Win32 c api, and if you're not using something like WinForms, MFC or another abstraction, it's hard to say why it works for you. I'm on a 4k resolution with 200% scaling and the button is way too thin.
binjooou: The whole point for me when using win32 is to use the default look, since it's a better ui compared to todays flat design. But I acknowledge that there could be a little less dpi work associated with enabling visual styles.
https://building.enlyze.com/posts/writing-win32-apps-like-it...