BottomNavigationView(1)

implementation 'com.google.android.material:material:1.2.1'

<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/navigation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:background="@android:color/white"
        app:layout_constraintBottom_toBottomOf="parent"
        app:menu="@menu/menu2" />



</androidx.constraintlayout.widget.ConstraintLayout>

public class MainActivity extends AppCompatActivity {

    private TextView mTextMessage;
    private static final String TAG = "MainActivity";
    BottomNavigationView navigation;//底部导航栏对象


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        init();

    }

    private void init() {

    navigation = (BottomNavigationView)findViewById(R.id.navigation);
    // 重新点击监听(即点击目前选中的Tab时触发)
        navigation.setOnNavigationItemReselectedListener(new BottomNavigationView.OnNavigationItemReselectedListener() {
        @Override
        public void onNavigationItemReselected(@NonNull MenuItem item) {
            Log.e("ee","Reselected Item:"+item.getTitle());
        }
    });
        navigation.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
        @Override
        public boolean onNavigationItemSelected(@NonNull MenuItem item) {
            Log.e("ee","Selected Item:"+item.getTitle());
            onTabSelected(item.getItemId());
            return true;
        }
    });
    onTabSelected(R.id.navigation_home);
}

　　　　

<menu xmlns:android="http://schemas.android.com/apk/res/android">


    <item
        android:id="@+id/navigation_home"
        android:icon="@drawable/bottom1"
        android:title="home" />

    <item
        android:id="@+id/navigation_dashboard"
        android:icon="@drawable/bottom2"
        android:title="dashboard" />

    <item
        android:id="@+id/navigation_notifications"
        android:icon="@drawable/bottom3"
        android:title="notifications" />

    <item
        android:id="@+id/navigation_setting"
        android:icon="@drawable/bottom4"
        android:title="share" />


</menu>