Kuidas rakendatakse ViewModeli kasutamist Jetpackis kasutajaliidese oleku haldamiseks?

Jetpack's ViewModel is used to store and manage UI state, preserving data during configuration changes (e.g., screen rotation). ViewModel separates UI logic from Activity or Fragment, making testing and maintenance easier.

Usage example:

class MyViewModel : ViewModel() {
    private val _text = MutableLiveData<String>()
    val text: LiveData<String> = _text

    fun updateText(newText: String) {
        _text.value = newText
    }
}

// In Activity or Fragment
val viewModel = ViewModelProvider(this).get(MyViewModel::class.java)
viewModel.text.observe(this) { updatedText ->
    textView.text = updatedText
}

Thus, ViewModel stores data that survives UI recreation and provides it via LiveData for reactive UI updates.