navigation bar or drawal android studio code example

Example 1: android studio remove navigation bar

protected void onResume() {
        super.onResume();
        View decorView = getWindow().getDecorView();
        // Hides the status and navigation bar until the user clicks
        // on the screeen.
        int uiOptions = View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                | View.SYSTEM_UI_FLAG_FULLSCREEN;
        decorView.setSystemUiVisibility(uiOptions);

Example 2: android bottom navigation hiding views

private fun setupNav() {
    val navController = findNavController(R.id.nav_host_fragment)
    findViewById<BottomNavigationView>(R.id.bottomNav)
        .setupWithNavController(navController)

    navController.addOnDestinationChangedListener { _, destination, _ ->
        when (destination.id) {
            R.id.mainFragment -> showBottomNav()
            R.id.mineFragment -> showBottomNav()
            else -> hideBottomNav()
        }
    }
}

private fun showBottomNav() {
    bottomNav.visibility = View.VISIBLE

}

private fun hideBottomNav() {
    bottomNav.visibility = View.GONE

}