ViewModel in Kotlin: Unresolved Reference

Question

I am trying to implement ViewModel in a 100% Kotlin app. Every piece of documentation I can find says I want to use this to get the ViewModel instance:

ViewM         


        

Answer 1

This can also be resolved by targeting minSdkVersion to 21.

If you have minSdkVersion 21 or higher, you won't need implementation "android.arch.lifecycle:extensions:1.1.1".

Answer 2

Include the following as a dependency:

implementation "android.arch.lifecycle:extensions:1.1.1"

This dependency is for both ViewModel and LiveData and thus would not require you to give separate dependencies for the same either; i.e. the first two dependencies indicated by you can be replaced by the aforementioned lifecycle extensions dependency.

Answer 3

android {
    kotlinOptions {
        jvmTarget = '1.8'
    } 
}

project e app level

Answer 4

I faced this kind of problem in AndroidStudio 3.0.1 and solved by adding following dependencies in the proper build.gradle:

implementation "android.arch.lifecycle:extensions:1.1.1"
annotationProcessor "android.arch.lifecycle:compiler:1.1.1"

version code may be different as AndroidStudio tells you if it differs.

Answer 5

In my case I was missing :

implementation "androidx.fragment:fragment-ktx:1.1.0"

Answer 6

If the above "adding/updating dependecies" did not resolve your issue then try to restart your android studio. It´s just to root, I do not see any major issue with it. Hope it helps.