toolbar添加背景

drawable:toolbar_shadow

<?xml version="1.0" encoding="utf-8"?>
<shape android:shape="rectangle"
    xmlns:android="http://schemas.android.com/apk/res/android">
    <gradient android:angle="90"
        android:startColor="@android:color/transparent"
        android:endColor="#FFC2C0C0">
    </gradient>
</shape>

<androidx.appcompat.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="@dimen/dp_44"/>

    <View
        android:layout_width="match_parent"
        android:layout_height="4dp"
        android:layout_below="@+id/toolbar"
        android:background="@drawable/toolbar_shadow"/>

本文地址：https://blog.csdn.net/qq_46237697/article/details/109379167