CODEWITHSUNDEEP
androidandroid-fragmentskotlin
Karl
Karl

Reputation: 111

Fragment$InstantiationException Kotlin MediaPlayer

I'm pretty new to Kotlin and I'm trying to create some exercise application in Android Studio. Now, I am using the Fragment Architecture for my app. I have a problem while trying to play a particular song on a fragment when I press a button to activate it.

private var mediaPlayer: MediaPlayer? = MediaPlayer.create(context, R.raw.workout_music)

and then in my onCreateView function:

mediaPlayer?.start()

and getting this error: 

android.support.v4.app.Fragment$InstantiationException: Unable to instantiate fragment com.example.bitamirshafiee.fitnessapp.ExerciseFragment: calling Fragment constructor caused an exception
        at android.support.v4.app.Fragment.instantiate(Fragment.java:465)

Upvotes: 0

Views: 146

Answers (1)

Demonick
Demonick

Reputation: 2126

context is null, because the constructor is called outside of the lifecycle, in field declaration, where context is not yet made. So that is why it can crash.

Making mediaPlayer a lateinit variable would remove the need for nullability. private lateinit var mediaPlayer: MediaPlayer then in onCreateView it could be initialised like mediaPlayer = MediaPlayer.create(context, R.raw.workout_music).

Upvotes: 1

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