Nougat 7.0  |  7.0.0_r31
Xml文件  |  5行  |  187 B 

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@color/camera_gray_background" />
</layer-list>