给控件添加阴影

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#484"
    android:clipChildren="false"
    android:gravity="center"
    android:orientation="vertical"
    tools:ignore="MissingDefaultResource">

    <LinearLayout 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="@dimen/dp60"
        android:background="@color/white"
        android:clipChildren="false"
        android:gravity="bottom"
        android:orientation="horizontal"
        tools:background="#484"
        tools:parentTag="androidx.appcompat.widget.LinearLayoutCompat">

        <View
            android:layout_width="@dimen/dp60"
            android:layout_height="@dimen/dp60"
            android:background="#00FF00" />

        <LinearLayout 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="wrap_content"
            android:layout_height="@dimen/dp50"
            android:background="@color/white"
            android:clipChildren="false"
            android:gravity="center"
            android:orientation="horizontal"
            tools:background="#484"
            tools:parentTag="androidx.appcompat.widget.LinearLayoutCompat">

            <LinearLayout 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="wrap_content"
                android:layout_height="@dimen/dp50"
                android:background="@color/white"
                android:clipChildren="false"
                android:gravity="center"
                android:orientation="vertical"
                tools:background="#484"
                tools:parentTag="androidx.appcompat.widget.LinearLayoutCompat">

                <View
                    android:layout_width="@dimen/dp60"
                    android:layout_height="@dimen/dp30"
                    android:background="#00FF00" />

                <View
                    android:layout_width="@dimen/dp60"
                    android:layout_height="@dimen/dp20"
                    android:background="#FF0000" />
            </LinearLayout>

            <View
                android:layout_width="@dimen/dp60"
                android:layout_height="@dimen/dp60"
                android:background="#0000FF" />
        </LinearLayout>

        <View
            android:layout_width="@dimen/dp60"
            android:layout_height="@dimen/dp55"
            android:background="@color/purple" />
    </LinearLayout>

    <View
        android:layout_width="@dimen/dp58"
        android:layout_height="@dimen/dp58"
        android:layout_gravity="center"
        android:layout_marginTop="@dimen/dp9"
        android:layout_marginBottom="@dimen/dp9"
        android:background="@drawable/white_circle_shape" />

    <View
        android:layout_width="@dimen/dp58"
        android:layout_height="@dimen/dp58"
        android:layout_gravity="center"
        android:layout_marginTop="@dimen/dp9"
        android:layout_marginBottom="@dimen/dp9"
        android:background="@drawable/white_circle_shape2" />

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="@dimen/dp88"
        android:background="#484"
        android:clipChildren="false"
        android:gravity="center"
        android:orientation="horizontal"
        android:visibility="visible"
        tools:ignore="MissingDefaultResource">

        <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
            xmlns:tools="http://schemas.android.com/tools"
            android:layout_width="@dimen/dp50"
            android:layout_height="@dimen/dp50"
            android:background="#FF00"
            android:clipChildren="false"
            android:gravity="center"
            android:orientation="vertical"
            tools:ignore="MissingDefaultResource" />

        <LinearLayout 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:id="@+id/rank_level_layout"
            android:layout_width="wrap_content"
            android:layout_height="@dimen/dp50"
            android:background="@color/white"
            android:clipChildren="false"
            android:gravity="center"
            android:orientation="vertical"
            tools:background="#484"
            tools:parentTag="androidx.appcompat.widget.LinearLayoutCompat">

            <FrameLayout
                android:layout_width="wrap_content"
                android:layout_height="@dimen/dp35"
                android:layout_gravity="center|bottom"
                android:clipChildren="false">

                <FrameLayout
                    android:id="@+id/contentlayout"
                    android:layout_width="@dimen/dp44"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center"
                    android:visibility="visible"
                    app:layout_constraintTop_toTopOf="parent">

                    <ImageView
                        android:id="@+id/images"
                        android:layout_width="@dimen/dp24"
                        android:layout_height="@dimen/dp24"
                        android:layout_gravity="center"
                        android:scaleType="fitXY"
                        app:layout_constraintLeft_toLeftOf="parent"
                        app:layout_constraintRight_toRightOf="parent"
                        tools:src="@drawable/main_tab_circle" />

                    <TextView
                        android:id="@+id/unread"
                        android:layout_width="@dimen/dp7"
                        android:layout_height="@dimen/dp7"
                        android:layout_gravity="right"
                        android:layout_marginRight="@dimen/dp10"
                        android:background="@drawable/msg_tips_shape"
                        android:gravity="center"
                        android:singleLine="true"
                        android:textColor="@color/white"
                        android:visibility="gone"
                        tools:text=""
                        tools:visibility="visible" />
                </FrameLayout>

                <!--                <FrameLayout 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="@dimen/dp58"-->
                <!--                    android:layout_height="@dimen/dp58"-->
                <!--                    android:layout_gravity="center"-->
                <!--            -->
                <!--                    android:visibility="gone"-->
                <!--                    app:layout_constraintTop_toTopOf="parent"-->
                <!--                    tools:showIn="@layout/widget_image_key_vertical_func_layout"-->
                <!--                    tools:visibility="visible">-->
                <!--                    <View-->
                <!--                        android:id="@+id/shadow_layer1"-->
                <!--                        android:layout_width="@dimen/dp58"-->
                <!--                        android:layout_height="@dimen/dp58"-->
                <!--                        android:layout_marginBottom="@dimen/dp9"-->
                <!--                        android:background="@drawable/main_tab_shadow_circle" />-->
                <!--                </FrameLayout>-->
                <!--                                <FrameLayout 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="@dimen/dp58"-->
                <!--                                    android:layout_height="@dimen/dp58"-->
                <!--                                    android:layout_gravity="center"-->
                <!--                            -->
                <!--                                    android:visibility="gone"-->
                <!--                                    app:layout_constraintTop_toTopOf="parent"-->
                <!--                                    tools:showIn="@layout/widget_image_key_vertical_func_layout"-->
                <!--                                    tools:visibility="visible">-->
                <!--                                </FrameLayout>-->
                <View
                    android:id="@+id/shadow_layer1"
                    android:layout_width="@dimen/dp58"
                    android:layout_height="@dimen/dp58"
                    android:layout_gravity="center"
                    android:layout_marginBottom="@dimen/dp9"
                    android:background="@drawable/white_circle_shape2" />
                <!--                    android:background="@drawable/main_tab_shadow_circle" />-->

                <View
                    android:id="@+id/shadow_layer2"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:background="@color/white" />

                <FrameLayout 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:id="@+id/shadow_layer3"
                    android:layout_width="@dimen/dp58"
                    android:layout_height="@dimen/dp58"
                    android:layout_gravity="center"
                    android:layout_marginBottom="@dimen/dp9"
                    android:visibility="visible"
                    app:layout_constraintTop_toTopOf="parent"
                    tools:showIn="@layout/widget_image_key_vertical_func_layout"
                    tools:visibility="visible">

                    <ImageView
                        android:id="@+id/shadow_images"
                        android:layout_width="@dimen/dp38"
                        android:layout_height="@dimen/dp38"
                        android:layout_gravity="center"
                        android:scaleType="fitXY"
                        android:src="@drawable/main_tab_circle"
                        app:layout_constraintLeft_toLeftOf="parent"
                        app:layout_constraintRight_toRightOf="parent" />

                    <TextView
                        android:id="@+id/shadow_unread"
                        android:layout_width="@dimen/dp7"
                        android:layout_height="@dimen/dp7"
                        android:layout_gravity="right"
                        android:layout_marginTop="@dimen/dp12"
                        android:layout_marginRight="@dimen/dp12"
                        android:background="@drawable/msg_tips_shape"
                        android:gravity="center"
                        android:singleLine="true"
                        android:textColor="@color/white"
                        android:visibility="gone"
                        tools:text=""
                        tools:visibility="visible" />
                </FrameLayout>

            </FrameLayout>

            <TextView
                android:id="@+id/keys"
                android:layout_width="wrap_content"
                android:layout_height="@dimen/dp15"
                android:includeFontPadding="false"
                android:textColor="@color/color_333333"
                android:textSize="9sp"
                android:textStyle="bold"
                app:layout_constraintTop_toBottomOf="@+id/contentlayout"
                tools:text="首页" />

        </LinearLayout>

        <!--        <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"-->
        <!--            xmlns:tools="http://schemas.android.com/tools"-->
        <!--            android:layout_width="@dimen/dp67"-->
        <!--            android:layout_height="@dimen/dp67"-->
        <!--            android:background="#FF00"-->
        <!--            android:clipChildren="false"-->
        <!--            android:gravity="center"-->
        <!--            android:orientation="vertical"-->
        <!--            tools:ignore="MissingDefaultResource" />-->

    </LinearLayout>

    <ImageView
        android:layout_width="@dimen/dp48"
        android:layout_height="@dimen/dp48"
        android:background="@drawable/white_circle_shape"
        android:visibility="gone" />

    <FrameLayout
        android:layout_width="@dimen/dp54_5"
        android:layout_height="@dimen/dp54_5"
        android:clipChildren="false"
        android:visibility="gone">

        <View
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_marginBottom="@dimen/dp6_5"
            android:background="@drawable/main_tab_shadow_circle" />

        <View
            android:layout_width="match_parent"
            android:layout_height="@dimen/dp35"
            android:layout_gravity="bottom"
            android:background="#FF00" />

        <ImageView
            android:layout_width="@dimen/dp38"
            android:layout_height="@dimen/dp38"
            android:layout_gravity="center"
            android:scaleType="fitXY"
            android:src="@drawable/main_tab_circle" />
    </FrameLayout>
</LinearLayout>

white_circle_shape2.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    tools:ignore="MissingDefaultResource">
    <item>
        <shape android:shape="oval">
            <padding
                android:bottom="@dimen/dp1"
                android:left="@dimen/dp1"
                android:right="@dimen/dp1"
                android:top="@dimen/dp1" />
            <solid android:color="#00CCCCCC" />
        </shape>
    </item>
    <item>
        <shape android:shape="oval">
            <padding
                android:bottom="@dimen/dp1"
                android:left="@dimen/dp1"
                android:right="@dimen/dp1"
                android:top="@dimen/dp1" />
            <solid android:color="#10CCCCCC" />
        </shape>
    </item>
    <item>
        <shape android:shape="oval">
            <padding
                android:bottom="@dimen/dp1"
                android:left="@dimen/dp1"
                android:right="@dimen/dp1"
                android:top="@dimen/dp1" />
            <solid android:color="#20CCCCCC" />
        </shape>
    </item>
    <item>
        <shape android:shape="oval">
            <padding
                android:bottom="@dimen/dp1"
                android:left="@dimen/dp1"
                android:right="@dimen/dp1"
                android:top="@dimen/dp1" />
            <solid android:color="#30CCCCCC" />
        </shape>
    </item>
    <item>
        <shape android:shape="oval">
            <padding
                android:bottom="@dimen/dp1"
                android:left="@dimen/dp1"
                android:right="@dimen/dp1"
                android:top="@dimen/dp1" />
            <solid android:color="#50CCCCCC" />
        </shape>
    </item>

    <!-- 中心背景 -->
    <item>
        <shape android:shape="oval">
            <!-- 实心 -->
            <solid android:color="#ffffff" />
                                    <padding
                                        android:bottom="@dimen/dp10"
                                        android:left="@dimen/dp10"
                                        android:right="@dimen/dp10"
                                        android:top="@dimen/dp10" />
        </shape>
    </item>
</layer-list>

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval">
    <solid android:color="@color/red" />

</shape>