Android:如何从Kotlin调用ndk函数？

Question

此代码适用于Java.但是在迁移到Kotlin之后,native fun stringFromNative(): String使用以下文本将编译器higlits方法 作为错误:

没有身体的功能必须是抽象的

class MainActivity : AppCompatActivity() {

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

    Toast.makeText(this, stringFromNative(), Toast.LENGTH_LONG).show()
}

companion object {

    init {
        System.loadLibrary("_ndkkt")
    }
    native fun stringFromNative(): String
}
}

谢谢@KenVanHoeylandt!

Andswer是:

class MainActivity : AppCompatActivity() {

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

    Toast.makeText(this, stringFromNative(), Toast.LENGTH_LONG).show()
}

   init {
        System.loadLibrary("_ndkkt")
    }

    external fun getStringFromNative(): String
}

}

Answer 1

Kotlin :

call method from ndk file
 external fun stringFromJNI(): String


 load c++ file
 companion object {
        init {
            System.loadLibrary("native-lib")
        }
    }

Answer 2

放在external fun stringFromNative(): String伴侣物体外面并进入MainActivity.

(我通过查看https://github.com/ligee/kotlin-ndk-samples找到答案)