Vertical Viewpager not working in kotlin android - android-studio

Question

I have been working on an app where were people can watch videos like tik tok. At first I made it with recyclerview and later on I realized that I should use Vertical Viewpager. Then I used Viewpager2 but I faced some problems so I replaced it with viewpager1. But still it is not working. I am doing this in my fragment. I want to play videos from firebase in Vertical viewpager using videoview.
In Viewpager_Adapter u can see that I have called one more layout there which is viewer_page but when I run my app I don't get that layout in my fragment
ViewpagerAdapter
class ViewpagerAdapter(var context: Context) : PagerAdapter() {
lateinit var inflater: LayoutInflater
var contentDTOs: ArrayList<ContentDTOs> = arrayListOf()
var contentUidList: ArrayList<String> = arrayListOf()
override fun isViewFromObject(view: View, `object`: Any): Boolean {
return view == `object` as ConstraintLayout
}
override fun destroyItem(container: ViewGroup, position: Int, `object`: Any) {
container.removeView(`object`as ConstraintLayout)
}
override fun instantiateItem(container: ViewGroup, position: Int): Any {
inflater = context.getSystemService(container.context.toString())as LayoutInflater
val view =inflater.inflate(R.layout.viewer_page,container,false)
val exo : View? = view?.findViewById(R.id.videoviews)
val path = Uri.parse(contentDTOs[position].videourl)
val views = view.findViewById<VideoView>(R.id.videoviews)
views.setVideoURI(path)
views.requestFocus()
views.setOnPreparedListener {
views.start()
}
container.addView(view)
return view
}
override fun getCount(): Int {
return contentDTOs.size
}
}
Watch_video_fragment
#SuppressLint("ResourceAsColor")
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
val fragmentview = inflater.inflate(R.layout.fragment_watch_video, container, false)
fragmentview.videofragment?.setOnClickListener {
var fragment = Watch_video()
activity?.supportFragmentManager?.beginTransaction()?.replace(R.id.frag, fragment)
?.commit()
}
fragmentview.memefragment?.setOnClickListener {
var fragment = DetailViewFragment()
activity?.supportFragmentManager?.beginTransaction()?.replace(R.id.frag, fragment)
?.commit()
}
firestore = FirebaseFirestore.getInstance()
uid = FirebaseAuth.getInstance().currentUser?.uid
fragmentview.videofragment?.setOnClickListener {
var fragment = Watch_video()
activity?.supportFragmentManager?.beginTransaction()?.replace(R.id.frag, fragment)
?.commit()
}
//
fragmentview.vertical_viewpager.adapter = ViewpagerAdapter(requireContext())
fragmentview.vertical_viewpager.setPageTransformer(false
) { page, position ->
page.rotationY = position * -30 // animation style... change as you want..
}
Can u guys plz help me