I think you mixed UI code with platform channel code. The only code that use platform channel is this line. https://github.com/flutter/flutter/blob/master/exam

I think you mixed UI code with platform channel code. The only code that use platform channel is this line. https://github.com/flutter/flutter/blob/master/examples/platform_channel/lib/main.dart#L27 https://github.com/flutter/flutter/blob/master/examples/plat... I really hope flutter can provide a guide for FFI though.