Exactly my experience. In general, for the sane person, it is impossible to write more than a few lines of Win32 API code without copy/paste... ChatGPT came quite handy here.

I'm confused. Are you sure high DPI needs patching system controls to avoid pixelation? Doesn't dpiAwareness avoid the pixelation? I certainly haven't needed to patch anything for this in the past. If you have an example you could point to, that would be great, since I don't know if I'm missing something here.

Also, question: do you know of a good way to test for high-DPI mode on a low-DPI screen?

You just need to add a manifest to your app indicating that you support high DPI. To test your app just change the DPI in the display settings.

I guess I was hoping for something little clunky than that, but thanks for the suggestion.

Nope, you get the pleasure of implementing dpi support yourself.

https://building.enlyze.com/posts/writing-win32-apps-like-it...

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?

I think you should try a plain win32 program on a high dpi and just see for yourself.

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 don't know why you assume I'm here to give you helpful answers, but I'll bite.

Try a combo box on high dpi. The arrow button gets a lot thinner than on 96 dpi.

Reply to your answer below: That is not the default Win32 combobox. I don't know what you're using, but it's not the plain c api

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.

And I did just try what you said and the combo box fine to me: https://imgur.com/a/Mb83tPj

That is not the default Win32 combobox. I don't know what you're using, but it's not the plain c api.

That is the default combobox if you enable "visual styles" (which you should do on Windows XP and above)

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.

The best UI is the UI your users are used to, and 1% of Windows users are used to the Win 2000 gray UI.

Win XP came out 22 years ago.

oblio: Have you seen the other comments for this post? There's plenty of people who think the default win32 gui is awesome.

This is most definitely the default combo box. At this point I'm very confused what you are using.

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.

I'm not sure if this makes a difference but do you see that problem with dialogs (resources + DialogBox) rather than basic windows?

If I remember & get a chance later I can try to make a minimal example.

No, win10

When you load a dialog from resource, windows scales it proportionally to specified font size (DS_FONT style).