实现按钮的selector
<?xml version=”1.0″ encoding=”utf-8″?><selector xmlns:android=”http://schemas.android.com/apk/res/android”> <item android:drawable=”@drawable/common_topbar_route_bus_pressed” android:state_pressed=”true”/> <item android:drawable=”@drawable/common_topbar_route_bus_pressed” android:state_selected=”true”/> <item android:drawable=”@drawable/common_topbar_route_bus_normal” android:state_enabled=”true”/> <item android:drawable=”@drawable/common_topbar_route_bus_normal” /></selector>