Android BottomNavigation Bar Round효과

drawable -> bottom_nav_round.xml 파일 생성후 아래와 같이 작성

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <solid
        android:color="@color/white"/>
    <corners
        android:topRightRadius="20dp"
        android:topLeftRadius="20dp"/>
    <stroke
        android:color="#F5F5F5"
        android:width="1dp"/>
</shape>

---

BottomBavigation태그 안에서 background color를 방금 만들어준 xml파일로 설정

android:background="@drawable/bottom_nav_round"

<?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">

    <fragment
        android:id="@+id/nav_host"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        app:navGraph="@navigation/nav_graph"
        app:defaultNavHost="true"
        app:layout_constraintBottom_toTopOf="@id/nav_bar"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/nav_bar"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:layout_gravity="bottom"
        android:background="@drawable/bottom_nav_round"
        app:itemIconTint="@drawable/item_color"
        app:itemTextColor="@drawable/menu_selector"
        app:labelVisibilityMode="labeled"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:menu="@menu/nav_bottom" />

</androidx.constraintlayout.widget.ConstraintLayout>

---

이렇게하면 위와 같이 변경된다.