Binding iOS Static Library to Xamarin.iOS and using the dll

Question

I am able to successfully create dll file for my Objective-C static library. But when I am try to reference that dll from Xamarin.iOS application and compiling, it is giving me lot of error like...

Error MT5210: Native linking failed, undefined symbol: _AudioFileClose. Please verify that all the necessary frameworks have been referenced and native libraries are properly linked in. (MT5210)

Error MT5210: Native linking failed, undefined symbol: std::ios_base::Init::Init(). Please verify that all the necessary frameworks have been referenced and native libraries are properly linked in. (MT5210)

Error MT5202: Native linking failed. Please review the build log. (MT5202)

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After this, I tried to link my .a library using Addtional mtouch Arguments. After adding those arguments, I am getting the new error.

Could not parse the command line arguments: Cannot bundle unregistered option '-o'.

Could someone please help me in resolving this issues.

Answer 1

As Stephane mentioned, there's a IsCxx property on the LinkWithAttribute that you can set to specify that the .a library is a c++ library. That'll solve the std::ios_base::Init::Init() error.

To solve the undefined symbol: _AudioFileClose error, you might try adding the CoreAudio or perhaps AudioToolbox framework to the list of frameworks to link against:

[assembly: LinkWith (..., IsCxx = true, Frameworks = "CoreAudio AudioToolbox")]

Hopefully even if that doesn't quite work, it'll get you headed in the right direction.

Answer 2

Finally figured out the error!!

    [assembly: LinkWith (..., IsCxx = true, Frameworks = "CoreAudio AudioToolbox", LinkerFlags = "-lstdc++ -lz" )]

In iOS Binding Projet

Options > Build > Compiler > Addition Arguments

    -cxx -gcc_flags "-stdlib=libstdc++ -L${ProjectDir} -lMylibrary -force_load ${ProjectDir}/libMylibrary.a”

In my demo application

Options > iOS Buidl > Addtional mtouch Arguments

    --gcc_flags="-stdlib=libstdc++"

By giving the proper flags in all the places it resolved my issue.

Answer 3

I resolved this problem installing the new version of Xcode. (now 7.1) The error is misleading but now it works!