如何访问在 Android Jetpack Compose 中注册到 MainActivity 的 ViewModel？

Question

Android documentation https://developer.android.com/topic/libraries/architecture/viewmodel details the creation and remember/retrieval of ViewModel instance that is registered with MainActivity .

My question is - how can I access this viewModel instant from other ViewModel or from @Compose function?

I have tried code

private val sessionViewModel: SessionViewModel by viewModels()

both in my classes descending from ViewModel and in @Composable functions, but viewModels() function is not available there.

He is how I have done registration:

class MainActivity : AppCompatActivity() {
    //...
    val sessionViewModel: SessionViewModel by viewModels<SessionViewModel>()
}

Answer 1

From a Composable, you would access you viewModel like this:

    @Composable
    fun MyScreen(
    viewModel: MyViewModel = viewModel()
    ) {
    // use viewModel here
    }

Source

As far as I know, you cannot access a viewModel from another viewModel, but see comment from Martin Marconcini below.