CODEWITHSUNDEEP
androidkotlinandroid-jetpackandroid-viewmodel
Jeffy
Jeffy

Reputation: 286

Lifecycle in Activity is not triggered in ViewModel

I am trying to execute a method(fun onCreateViewModel()) in viewModel whenever the onCreate of the Activity is invoked. But the method is not getting executed.

ViewModel

class MainActivityViewModel(startingCount : Int) : ViewModel(), LifecycleObserver {
    var count = 0

    init {
        count = startingCount
    }

    fun getCurrentCount(): Int{
        return count
    }

    fun getUpdatedCount(): Int {
        count ++
        return count
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_CREATE)
    public fun onCreateViewModel(){
        Log.i("Jts","   ViewModel created")
    }
}

Activity

class MainActivity : AppCompatActivity() {

    private lateinit var binding: ActivityMainBinding
    private var user = User("Jeffin T", "26")
    private lateinit var mainActivityViewModel: MainActivityViewModel
    private lateinit var mainActivityViewModelFactory: MainActivityViewModelFactory


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
//        mainActivityViewModel = ViewModelProviders.of()
        mainActivityViewModelFactory = MainActivityViewModelFactory(123)
        mainActivityViewModel = ViewModelProviders.of(this, mainActivityViewModelFactory)
            .get(MainActivityViewModel::class.java)
        binding = DataBindingUtil.setContentView(this, R.layout.activity_main)
        binding.tvName.text = mainActivityViewModel.getCurrentCount().toString()
        binding.user = user
        binding.btnName.setOnClickListener {
            binding.tvName.text = mainActivityViewModel.getUpdatedCount().toString()
        }
    }

    private fun displayGreeting() {
        binding.apply { tvName.setText("Hello! " + user?.name) }
    }
}

Upvotes: 1

Views: 723

Answers (1)

ritatferreira
ritatferreira

Reputation: 61

You have to add the viewmodel as an observer of the lifecycle of your activity. You need to add this in your Activity

getLifecycle().addObserver(viewModel)

More info here

Upvotes: 3

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