Create Bottom Navigation in Android

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Mamu create

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<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:title="action_Home"
        android:id="@+id/Home"
        android:icon="@drawable/home"
        />
    <item
        android:title="Action_setting"
        android:id="@+id/view"
        android:icon="@drawable/ic_baseline_settings_24"/>

</menu>

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Calling the fragments

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loadFragment(new HomeFragment());

   binding.bottomNav.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
       @Override
       public boolean onNavigationItemSelected(@NonNull MenuItem item) {
           switch (item.getItemId()){
               case R.id.Home:
                   loadFragment(new HomeFragment());
                   break;

               default:
                   loadFragment(new SettingFragment());
                   break;
           }
           return true;
       }
   });

private void loadFragment(Fragment f){
    FragmentTransaction  ft =
            getSupportFragmentManager().beginTransaction();
    ft.replace(R.id.frament_container, f);
    ft.commit();
}

 

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XML side code create bottom navigation

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<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=".bottomnav">

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

</RelativeLayout>

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bottom navigation Back state Save

//============================java Code Start =========================================

@Override public void onBackPressed() {
    Fragment fragment = getSupportFragmentManager().findFragmentById(R.id.fragment_container);
    if (!(fragment instanceof HomeFragment)) {
        loadFragment(new HomeFragment());
    }
    else { super.onBackPressed();
    }
}