Detect MIDI device connect / disconnect?

[railjonrogut]

See this thread:

How to update Midi Device

I have used JUCE about half a year.Now I'm writing a app need to check and open midi device on OSX .I set up a background thread to check updated midi device all the time by using OSX's API . But devices will either never be found, if they are not connected on startup, MIDIGetNumberOfDestinations() and MIDIGetNumberOfSources() coundn't update about the plugged device . If they are connected on startup,app can find out the device,then unplug ,the two functions didn't found out that device had bee…

Rail