guanguan_app1/app/src/main/res/drawable/sidebar_background.xml

<?xml version="1.0" encoding="utf-8"?>
<shape android:shape="rectangle"
  xmlns:android="http://schemas.android.com/apk/res/android">
    <gradient android:startColor="#E7E7E7" android:endColor="#E7E7E7" android:angle="90.0" />
    
    <corners
        android:topLeftRadius="8dip"
        android:bottomLeftRadius="8dip"/>
    
</shape>