tryradiobutton_bg.xml<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android"> 
<item 
android:state_enabled="true"
android:state_checked="true"
android:drawable="@android:drawable/radiobutton_off_background" /> 
<item 
android:state_enabled="true" 
android:state_checked="false"
android:drawable="@android:drawable/radiobutton_off_background" />
</selector>
 android:button="@drawable/radiobutton_bg"