一些经典的drawable样式案例

• 透明渐变底色

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <gradient
        android:startColor="#22000000"
        android:endColor="#88000000"
        android:angle="90"/>
</shape>

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <gradient
        android:startColor="#00000000"
        android:centerColor="#11000000"
        android:endColor="#55000000"
        android:angle="270"/>
</shape>