Using Windows system dlls on Hololens 2 when compiled with IL2CPP

Questions & Answers
1

Hello,

I’m building an App which requires the use of the MAC Address of the Hololens 2 (I’m not uploading the App to the Windows Store so no worries about security here). To do so I’ve used the iphlpapi.dll. To test that this worked at all, I created a stand alone UWP App and deployed it to the Hololens. This worked perfectly well and there were no issues. I didn’t need to specify the location of the dll etc, the import simply worked.

The code sample I used was from here:

https://stackoverflow.com/questions/34097870/c-sharp-get-mac-address-in-universal-apps/34098615

I built this code into my Unity App, compiled it and then deployed it to the Hololens. It didn’t work of course. I tried hard coding the full dll path in the import in the generated C++ but not luck.

Is there something I need to do, to allow the code to access the DLL?

Any tips or help would be much appreciated. The exact error I can get tomorrow, I’m currently not in the office.

Many thanks in advance,
Peter

2

The Dll needs to be present (Intel Architecture) in the project. However, you need to use this DllImport:

[DllImport("__Internal", CharSet = CharSet.Ansi, ExactSpelling = true)]

This allows the dll to be statically linked. Hope this helps someone as it’s been a real pain for me.