How to find the local IP (LAN) address of the PC

[andreaQt]

Please read all, and don't tell me: if you forced it you know it, my goal is to find the IP of LAN even if i don't forced it.

I use Qt version 5.12.0 (see Version.jpg).

I built this program/modify because i need to have an interface that show the incoming UDP message on a specific port, my trouble is that i can't find the IP of the LAN (that i've forced before, see LAN.jpg) if i'm connected to internet => the program that i've wrote show me the IP of the internet connection and if i'm not connected to interne the program show me the right IP of the LAN (this is done in "Test cath Info 1").
Using "Test catch Info 2" i can show all the current connection LAN + internet, ecc, i test it that it is right using ipconfig command.
Using "Test catch Info 3" i try to find it by using the procedure/class "QNetworkInterface::xxxxxxxxxxxxxxx" but with no result at the moment (see Test_3a.jpg & Test_3_b.jpg).

Tell me where i do the mistake, or an alternative solution.

Thank you.

[Lesiok]

What does it mean "i'm connected to internet" ?
I'm connected to internet and Your program shows correct interface data (that is, the address in the internal network).

PS.
QNetworkInterface::inetrfaceFromName looks for interface name not host name.