ThreeLocation/app/src/main/res/values-v21/styles.xml

<resources>
    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/black</item>
        <item name="colorPrimaryDark">@color/black</item>
        <item name="colorAccent">@color/colorAccent</item>
        <!--导航栏不透明-->
        <item name="android:windowTranslucentNavigation">false</item>
        <!--导航栏为黑色-->
        <item name="android:navigationBarColor">@color/black</item>
    </style>

</resources>