按钮状态自定义：
<?xml version="1.0" encoding="UTF-8"?> <selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:state_pressed="true" android:drawable="@drawable/play_pressed" /> <!-- pressed --> <item android:state_focused="true" android:drawable="@drawable/play_normal" /> <!-- focused --> <item android:drawable="@drawable/play_normal" /> <!-- default --> </selector>