the menu items cant appear in navigatin bar in android studio

Question

I'm trying to make navigatin bar I did menu and put 2 items but when i ame trying to put it in activity_main.xml the items not appear(buttons)

here my codes:

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

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/bottom_navigatin_view"
        android:layout_width="match_parent"
        android:layout_height="70dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:menu="@menu/menu"/>

</androidx.constraintlayout.widget.ConstraintLayout>

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



    <item
        android:id="@+id/homeFragment"
        android:icon="@drawable/home_icon"
        android:title="Item"
        />

    <item
        android:id="@+id/creatFragment"
        android:icon="@drawable/creat_icon"
        android:title="Item"
        />

</menu>

Answer 1

Here’s the dependency we need to add:

implementation ‘com.google.android.material:material:1.2.0’

activity_main.xml file

   <?xml version="1.0" encoding="utf-8"?>
<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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
 
    <FrameLayout
        android:id="@+id/flFragment"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        app:layout_constraintBottom_toTopOf="@+id/bottomNavigationView"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
 
    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/bottomNavigationView"
        android:layout_width="match_parent"
        android:layout_height="75dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toStartOf="parent"
        app:menu="@menu/bottom_nav_menu"/>
     
</androidx.constraintlayout.widget.ConstraintLayout>

You can customize the Action Bar:

<resources>
    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.MaterialComponents.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>
 
</resources>

And then creating Fragments to display:

<?xml version="1.0" encoding="utf-8"?>
<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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/firstFragment"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello Param"
        android:textColor="#43a047"
        android:textSize="40sp"
        android:textStyle="italic|bold"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

Activity:

import java.io.*;
import androidx.appcompat.app.AppCompatActivity;
import androidx.annotation.NonNull;
import com.example.Fragment.*;
import com.google.android.material.bottomnavigation.BottomNavigationView;
import android.os.Bundle;
import android.view.MenuItem;

public class MainActivity extends AppCompatActivity implements BottomNavigationView.OnNavigationItemSelectedListener {

    BottomNavigationView bottomNavigationView;

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

        bottomNavigationView = findViewById(R.id.bottomNavigationView);
    
        bottomNavigationView.setOnNavigationItemSelectedListener(this);
        bottomNavigationView.setSelectedItemId(R.id.homeFragment);

    }
    FirstFragment firstFragment = new FirstFragment();
    SecondFragment secondFragment = new SecondFragment();
    
    @Override
    public boolean onNavigationItemSelected(@NonNull MenuItem item) {

        switch (item.getItemId()) {
            case R.id.homeFragment:
                getSupportFragmentManager().beginTransaction().replace(R.id.container, firstFragment).commit();
                return true;

            case R.id.create_icon:
                getSupportFragmentManager().beginTransaction().replace(R.id.container, secondFragment).commit();
                return true;

        }
        return false;
    }
}

Please change your resouce activity:

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

    <item
        android:id="@+id/homeFragment"
        android:icon="@drawable/home_icon"
        android:title="Item"
        />

    <item
        android:id="@+id/creatFragment"
        android:icon="@drawable/creat_icon"
        android:title="Item"
        />

</menu>