AdapterClass:
class TeamsAdapter(
supportFragmentManager: FragmentManager,
teams_list: MutableList<Team>,
match_id: String
) : FragmentPagerAdapter(supportFragmentManager) {code}
Fragment Class:
lateinit var teamsAdapter: TeamsAdapter
teamsAdapter = TeamsAdapter(supportFragmentManager, match?.teams!!, matchId)
Error: Unresolved reference: supportFragmentManager
But the entire code works fine when inside an Activity instead of Fragment Class.
Solved by casting activity if you are using fragment then cast with context
fragmentManager = (activity as FragmentActivity).supportFragmentManager
childFragmentManager for nesting fragments.you can use parentFragmentManager or childFragmentManager for using fragment manager inside of a fragment. There is no need to use any sort of casting for using a fragment manager.
parentFragmentManager or getParentFragmentManager()
Return the FragmentManager for interacting with fragments associated with this fragment's activity. Note that this will available slightly before {@link #getActivity()}, during the time from when the fragment is placed in a {@link FragmentTransaction} until it is committed and attached to its activity.If this Fragment is a child of another Fragment, the FragmentManager returned here will be the parent's {@link #getChildFragmentManager()}. @throws IllegalStateException if not associated with a transaction or host.
childFragmentManager or getChildFragmentManager()
Return a private FragmentManager for placing and managing Fragments inside of this Fragment.
I just read that you are learning something new, so I suggest it is better to use the best practices. Casting sometimes generates errors and crashes, so I suggest you use these.
When your fragment contains a ViewPager that uses fragments, you must always use the childFragmentManager for that ViewPager as that's what allows FragmentManager to properly nest those fragments and ensure that their state is properly saved and restored.
You should use supportFragmentManager if you are supporting device below API 14, otherwise just use fragmentManager
androidx.fragment.app.Fragment is based on support library (android.app.Fragment was deprecated). So, you cannot use fragmentManager, only supportFragmentManager . Also fragmentManager was deprecated.