I am attempting to get a Native C/C++ library working with Monodroid in the emulator, using DllImport. I am developing mainly in Windows/Visual Studio 2010.
I have built a native C/C++ library (ZeroMQ) using the Android NDK tools, to both x86 and armeabi platforms, using a Ubuntu virtual machine. Is this correct – x86 for emulator and armeabi for the real device? (This is certainly the case on the iPhone/MonoTouch – though in that case statically linked libzmq.a file and DllImport __Internal)
I have added the x86 version of libzmq.so to my MonoDroid project under the directory structure lib\x86\libzmq.so
When I first attempted to build/deploy to the simulator, I got an error ‘cannot determine abi type’, so I’ve added x86 to the AndroidNativeLibrary Include=”lib\x86\libzmq.so”> project item group. This then deployed.
I have a DllImport for the function to call [DllImport(“libzmq”
I’ve tried libzmq.so, lib/x86/libzmq, lib/x86/libzmq.so etc, but then I call the DllImported method (running in the emulator), I always get a DllNotFoundException.
Can anyone give me some direction?
EDIT: After reading another support answer which states that the emulator uses armeabi .so libraries, I have removed the x86/libzmq and added my lib/armeabi/libzmq.so as an AndroidNativeLibrary. I also removed the project file Abi entry, and indeed the project built and deployed fine.
However, I still get a DllNotFoundException when I try to call a DllImported function. Any ideas?
Many thanks
Ok, I finally got it working! For whatever reason, ZeroMQ doesn’t build correctly using the current/latest NDK r7. The instructions at http://www.zeromq.org/build:android use NDK r6. I also downloaded an old version of the NDK r5b (it was the easiest old version to find a download for), and rebuilt ZeroMQ using it. Result, it now works on emulator and phone!