Why does BottomNavigationView not changing selected tab Icon?

Question

I have added BottomNavigationView. When i tap on any tab then only Fragment is get replaced, it does not showing the new selected tab Icon and Title (Home tab is always shows as selected) What is the problem?

My XML layout - MainActivity.xml

<RelativeLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <FrameLayout
        android:id="@+id/FragmentContainerFrameLayout"
        android:layout_above="@id/bottomNavAppBar"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <com.google.android.material.appbar.AppBarLayout
        android:id="@+id/bottomNavAppBar"
        android:layout_alignParentBottom="true"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <com.google.android.material.bottomnavigation.BottomNavigationView
            app:labelVisibilityMode="unlabeled"
            android:id="@+id/bottomNavgView"
            app:menu="@menu/bottom_nav"
            android:background="?android:attr/windowBackground"
            app:itemTextColor="#000"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>
    </com.google.android.material.appbar.AppBarLayout>

</RelativeLayout>

My java code - MainActivity.java

public class MainActivity extends AppCompatActivity implements BottomNavigationView.OnNavigationItemSelectedListener {

    BottomNavigationView bottomNavigationView;
    Fragment selectedFragment;
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        bottomNavigationView=findViewById(R.id.bottomNavgView);
        bottomNavigationView.setOnNavigationItemSelectedListener(this);
    }

    @Override
    public boolean onNavigationItemSelected(@NonNull MenuItem item) {
        switch (item.getItemId())
        {
            case R.id.homeMenu:
                selectedFragment=new HomeFragment();
                break;

            case R.id.searchMenu:
                selectedFragment=new SearchFragment();
                break;

            case R.id.addPostMenu:
                selectedFragment=null;
                startActivity(new Intent(MainActivity.this,AddPostActivity.class));
                break;

            case R.id.likesMenu:
                selectedFragment=new LikesFragment();
                break;

            case R.id.profileMenu:
                selectedFragment=new ProfileFragment();
                break;
        }

        if(selectedFragment!=null)
        {
            FragmentTransaction transaction=getSupportFragmentManager().beginTransaction();
            transaction.replace(R.id.FragmentContainerFrameLayout,selectedFragment);
            transaction.commit();
        }
        return false;
    }
}

Color file - @menu/bottom_nav

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:color="@android:color/black" android:state_checked="true"/>
    <item android:color="@android:color/darker_gray"/>
</selector>

Gradle file

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])

    implementation 'androidx.appcompat:appcompat:1.1.0'
    implementation 'com.google.android.material:material:1.1.0'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    implementation 'androidx.legacy:legacy-support-v4:1.0.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
}

Menu file

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item

        android:id="@+id/homeMenu"
        android:title="Home"
        android:icon="@drawable/ic_home"></item>

    <item
        android:id="@+id/searchMenu"
        android:title="Search"
        android:icon="@drawable/ic_search"></item>


    <item
        android:id="@+id/addPostMenu"
        android:title="Add Post"
        android:icon="@drawable/ic_add_post"></item>


    <item
        android:id="@+id/likesMenu"
        android:title="Likes"
        android:icon="@drawable/ic_like"></item>

    <item
        android:id="@+id/profileMenu"
        android:title="Profile"
        android:icon="@drawable/ic_profile"></item>

</menu>

I have not performed something out of the world, Why does this happening? Please Help me.

• First menu item icon is always selected,not changing

• Proper Fragment is replaced but not showing Icon and Title.

Answer 1

You have to return true in the onNavigationItemSelected method:

    @Override
    public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
       ...
       return true;  
    }

You can check the doc:

Returns

boolean true to display the item as the selected item and false if the item should not be selected. Consider setting non-selectable items as disabled preemptively to make them appear non-interactive.

Also you are using app:labelVisibilityMode="unlabeled".
It means that the label is hidden for all navigation items (LABEL_VISIBILITY_UNLABELED)