ScopedViewModel

DetailViewModel.kt

class DetailViewModel : ScopedViewModel() {
  
    fun startTask() {
        launch {
            // Switch the 'background' thread 
            withContext(Dispatchers.Default) {
                // do your long-running thing
            }
            // We're now back on the Android's Main thread
            updateUi()
        }
    }
    
}

ScopedViewModel.kt

open class ScopedViewModel : ViewModel(), CoroutineScope {
    private val job = Job()
   
    override val coroutineContext: CoroutineContext
        get() = job + Dispatchers.Main

    override fun onCleared() {
        super.onCleared()
        job.cancel()
    }
}