android 图片背景使用这种方式很爽

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
 <item
  android:state_pressed="false"
  android:drawable="@drawable/button_green_three1"
 />
 
 <item
  android:state_pressed="true"
  android:drawable="@drawable/button_green_three_press"
 />
 
 <item
  android:drawable="@drawable/button_green_three1"
 />
</selector>