How to convert wav to flac on Android?

I want to convert a wav file to a flac file on Android. I found this:

I’ve put it into Plugins/Android folder but I don’t know how to use its function in C# scripts. I tried this:

[DllImport(“javaFlacEncoder-0.3.1”)]

But it gave the following error:

error CS0592: The attribute System.Runtime.InteropServices.DllImportAttribute' is not valid on this declaration type. It is valid on method’ declarations only

you can use Avdshare Audio Converter to Convert WAV to FLAC,MP3, AIFF, AAC, WMA, AC3, MP2, OGG, M4A and other audio formats to further extend WAV usage on more media players or portable devices.