BottomNavigation (Android)

Introduction

How can you add bottom navigation to an Android app using Java and XML?

What is Bottom Navigation?

Bottom navigation bars display three to five destinations at the bottom of a screen. Each destination is represented by an icon and an optional text label. When a bottom navigation icon is tapped, the user is taken to the top-level navigation destination associated with that icon.

How to add

Create a `MainActivity.java` file and include the code provided below.

MainActivity.java

Here’s a simple example of a MainActivity.java:

          
    
package com.example.bottomnavigationapp;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;

import android.os.Bundle;
import android.view.MenuItem;

import com.google.android.material.bottomnavigation.BottomNavigationView;

import org.jetbrains.annotations.NotNull;

public class MainActivity extends AppCompatActivity {

    BottomNavigationView bottomNavigationView;

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

        bottomNavigationView = findViewById(R.id.bottomnavigation);
        bottomNavigationView.setOnNavigationItemSelectedListener(navigationItemReselectedListener);

        getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, new HomeFragment()).commit();
    }

    private final BottomNavigationView.OnNavigationItemSelectedListener navigationItemReselectedListener = new BottomNavigationView.OnNavigationItemSelectedListener() {
        @Override
        public boolean onNavigationItemSelected(@NonNull @NotNull MenuItem item) {
            Fragment selectedFragment = null;

            switch (item.getItemId()){
                case R.id.Home:
                    selectedFragment = new HomeFragment();
                    break;
                case R.id.search:
                    selectedFragment = new SearchFragment();
                    break;
                case R.id.Profile:
                    selectedFragment = new ProfileFragment();
                    break;

            }

            getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, selectedFragment).commit();
            return true;
        }
    };

}

Create a `MainActivity.xml` file and include the code provided below.

MainActivity.xml

Here’s a simple example of a MainActivity.xml:

          
    
<?xml version="1.0" encoding="utf-8"?>
<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">

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/bottomnavigation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        app:menu="@menu/navigation_menu"/>

    <FrameLayout
        android:id="@+id/fragment_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@id/bottomnavigation">

    </FrameLayout>
</RelativeLayout>

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