Junior — Middle

How is the ViewModel used in Jetpack to manage UI state?

sobes.tech AI

Answer from AI

The ViewModel in Jetpack is used to store and manage UI-related data, preserving it during configuration changes (such as screen rotations). ViewModel separates UI logic from Activity or Fragment, making testing and maintenance easier.

Example usage:

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 through LiveData for reactive UI updates.

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