[BUG]: Device add/removal not changing midiInGetNumDevs as expected

[Psychlist1972]

Windows Version

Canary 27808 / 27802

Service Installation Method

GitHub

SDK version, if appropriate

Customer Preview 2

Location

Application using WinMM MIDI 1.0 (Classic API)

Type of bug

Application not working as expected

Steps to reproduce

Reported by Giel Bremmers on Discord https://discord.com/channels/980245825202552942/1348006763122655302

Start WinMM version of MultitrackStudio
Plug in a USB keyboard (I used a plain old MIDI 1.0 keyboard)

observed: midiInGetNumDevs() returns the same number. Midi.exe does enumerate the new keyboard though. You have to close MultitrackStudio and start it again to see the new keyboard.

The same problem exists when you unplug the keyboard: midiInGetNumDevs() still returns the same number, and you can still get the name of the keyboard.

I doubt it's related to that issue ( #483 ). It works fine if MultitrackStudio uses the Windows MIDI Services. It does not work as expected if MultitrackStudio uses WinMM. So to me it looks like it's not the service or the driver, it's the WinMM layer. But I don't know anything about how that works internally, so I could be wrong

Expected behavior

expected: midiInGetNumDevs() now returns a different number (one more than before)

Additional notes

No response

[Psychlist1972]

This has been fixed in Preview 13