處理已啟用已禁用狀態

建立選擇器以啟用/禁用選單項。

selector.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:color="@color/white" android:state_enabled="true" />
    <item android:color="@color/colorPrimaryDark" android:state_enabled="false" />
</selector>

design.xml

<android.support.design.widget.BottomNavigationView
    android:id="@+id/bottom_navigation"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    app:itemBackground="@color/colorPrimary"
    app:itemIconTint="@drawable/nav_item_color_state"
    app:itemTextColor="@drawable/nav_item_color_state"
    app:menu="@menu/bottom_navigation_main" />