Android Studio 3.4.1, Kotlin "unresolved reference: mutableListOf"

Question

I am building an AAR with Kotlin in Android Studio 3.4.1, and I get the dreaded "unresolved reference" error when I try to use mutableListOf.

 val myBuffer: mutableListOf<Byte>()

I updated Kotlin to the latest version at the time of writing

In build.gradle, the Kotlin version is also consistently defined.

In the module build.gradle, the following plugins are used:

apply plugin: 'com.android.library'

apply plugin: 'kotlin-android'

apply plugin: 'kotlin-android-extensions'

I understood from what I read, that the Kotlin language plugin, including collection classes, should be automatically included in Android Studio. In any case, I'm using other Kotlin classes, eg ByteArray, without a problem.

Following advice that I found online, I cleaned and re-built, also selected File | Invalidate Caches/Restart and re-built. It did not work; the reference is still unresolved.

The Kotlin documentation doesn't say that this function is deprecated, which was another possible cause that I found.

What am I missing?

Answer 1

You have made some typo error: use = and not : :

 val myBuffer = mutableListOf<Byte>()

or specify type explicitly:

 val myBuffer: MutableList<Byte> = mutableListOf<>()

Answer 2

未解决的mutableListOf或MutableList引用请尝试实现此依赖项：

implementation 'androidx.core:core-ktx:$kotlin_version'

Answer 3

lates version:

val myBuffer: MutableList<Byte> = mutableListOf()