从 MVVM 架构中的 ViewModel 更改片段

Question

I am developing an agenda app for practise MVVM architecture and SQLite databases but i need to change fragment from inside of fragment. So for calendarFragment i created this viewModel but i can't use .supportFragmentManager method without MainActivity context. How can i solve this problem ?

class calendarFragmentViewModel(application: Application) : AndroidViewModel(application) {

    fun fragmentChanger(fragment : Fragment, context: Context?) {
        var transaction = (context as MainActivity).supportFragmentManager.beginTransaction()
            transaction.replace(com.cagataysencan.agendea.R.id.frameLayout,fragment)
            transaction.commit()
        }
    }

Answer 1

You can use LiveData with your ViewModel for this purpose.

Observe the LiveData from your Fragment and once that LiveData provides an update, we'll get it in Fragment. Inside the callback, you can launch from the observing fragment.