viewPager2 = findViewById(R.id.viewPager2)
        viewPager2.adapter = Adapter(this)
        viewPager2.registerOnPageChangeCallback(object : ViewPager2.OnPageChangeCallback(){
            override fun onPageSelected(position: Int) {
                super.onPageSelected(position)
                when(position){
                    0 -> bottomNavigationView.selectedItemId = R.id.home
                    1 -> bottomNavigationView.selectedItemId = R.id.message
                    2 -> bottomNavigationView.selectedItemId = R.id.person
                }
            }
        })

        bottomNavigationView = findViewById(R.id.bottom)
        bottomNavigationView.setOnItemSelectedListener {
            when(it.itemId){
                R.id.home -> {viewPager2.currentItem = 0}
                R.id.message -> {viewPager2.currentItem = 1}
                else -> {viewPager2.currentItem = 2}
            }
            true
        }

====================================================================================================================


            AlertDialog.Builder(requireActivity())
                .setTitle("hi")
                .setCancelable(true)
                .setMessage("no hi")
                .setPositiveButton("go"){_,_ ->
                    activity.bottomNavigationView.selectedItemId = R.id.home
                }
                .setNegativeButton("no go"){_, _ ->

                }
                .show()