BottomNavigationView+ViewPager打造底部导航栏

效果

BottomNavigationView的简单使用
官网推荐使用方式：

layout resource file:
 "http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     android:id="@+id/navigation"
     android:layout_width="match_parent"
     android:layout_height="56dp"
     android:layout_gravity="start"
     app:menu="@menu/my_navigation_items" />

 res/menu/my_navigation_items.xml:
 "http://schemas.android.com/apk/res/android">
     <item android:id="@+id/action_search"
          android:title="@string/menu_search"
          android:icon="@drawable/ic_search" />
     <item android:id="@+id/action_settings"
          android:title="@string/menu_settings"
          android:icon="@drawable/ic_add" />
     <item android:id="@+id/action_navigation"
          android:title="@string/menu_navigation"
          android:icon="@drawable/ic_action_navigation_menu" />