如何设置android中底部导航栏的顶部边框,如图所示

Question

是否可以在android中设置底部导航栏的顶部边框,如果可能的话告诉我如何做到这一点,我正在使用android的新底部导航视图. 这是我的代码

<?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"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
        <LinearLayout
            android:id="@+id/app_bar_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:layout_alignParentTop="true">
                <include
                    android:id="@+id/gamebar"
                    layout="@layout/gamebar_layout"
                    />
                <include
                    android:id="@+id/toolbar"
                    layout="@layout/toolbar_layout" />
        </LinearLayout>

        <!-- Let's add fragment -->
        <FrameLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@+id/app_bar_layout"
            android:layout_above="@+id/bottom_navigation"
            android:id="@+id/contentContainer"/>
        <android.support.design.widget.BottomNavigationView
            android:id="@+id/bottom_navigation"
            android:layout_width="match_parent"
            android:layout_height="56dp"
            android:layout_alignParentBottom="true"
            app:itemBackground="@color/BottomNavigationBgColor"
            app:itemIconTint="@color/CelestialBlue"
            app:itemTextColor="@color/CelestialBlue"
            app:menu="@menu/bottom_navigation_main" />
</RelativeLayout>

Answer 1

你可以试试这个:在View上面添加一个元素BottomNavigationView

<View
    android:layout_width="match_parent"
    android:layout_height="4dp"
    android:layout_above="@+id/bottom_navigation"
    android:background="#000000"></View>

<android.support.design.widget.BottomNavigationView
    android:id="@+id/bottom_navigation"
    android:layout_width="match_parent"
    android:layout_height="56dp"
    android:layout_alignParentBottom="true"
    app:itemBackground="@color/BottomNavigationBgColor"
    app:itemIconTint="@color/CelestialBlue"
    app:itemTextColor="@color/CelestialBlue"
    app:menu="@menu/bottom_navigation_main" />

Answer 2

1. 使用XML定义可绘制的背景：

   <layer-list xmlns:android="http://schemas.android.com/apk/res/android">
       <item>
           <shape android:shape="rectangle">
               <solid android:color="@color/colorPrimaryDark" />
           </shape>
       </item>
       <item android:top="1dp">
           <shape android:shape="rectangle">
               <solid android:color="@color/colorWhite" />
           </shape>
       </item>
   </layer-list>
   

2. 使用它作为背景

   android:background="@drawable/myBackgroundBottomDrawer"