Answers for "hide bottom navigation bar android"

android hide and show bottom navigation

public class BottomNavigationViewBehavior extends CoordinatorLayout.Behavior<BottomNavigationView> {

private int height;

@Override
public boolean onLayoutChild(CoordinatorLayout parent, BottomNavigationView child, int layoutDirection) {
    height = child.getHeight();
    return super.onLayoutChild(parent, child, layoutDirection);
}

@Override
public boolean onStartNestedScroll(@NonNull CoordinatorLayout coordinatorLayout,
                               BottomNavigationView child, @NonNull 
                               View directTargetChild, @NonNull View target,
                               int axes, int type)
{
    return axes == ViewCompat.SCROLL_AXIS_VERTICAL;
}

@Override
public void onNestedScroll(@NonNull CoordinatorLayout coordinatorLayout, @NonNull BottomNavigationView child,
           @NonNull View target, int dxConsumed, int dyConsumed,
           int dxUnconsumed, int dyUnconsumed, 
            @ViewCompat.NestedScrollType int type)
{
   if (dyConsumed > 0) {
       slideDown(child);
   } else if (dyConsumed < 0) {
       slideUp(child);
   }
}

private void slideUp(BottomNavigationView child) {
    child.clearAnimation();
    child.animate().translationY(0).setDuration(200);
}

private void slideDown(BottomNavigationView child) {
    child.clearAnimation();
    child.animate().translationY(height).setDuration(200);
}

remove elivation on android studio bottom navigation bar

<android.support.design.widget.BottomNavigationView
    android:id="@+id/bottom_navigation"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:background="@android:color/white"
    app:elevation="0dp"
    app:menu="@menu/bottom_navigation_main" />