ExpandableListView的小图标有个状态

expandableView.setGroupIndicator(this.getResources().getDrawable(R.drawable.ic));
 /////////////////////

res/drawable/ic.xml:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_expanded="true"    
android:drawable="@drawable/icon" />
 
<item     
android:drawable="@drawable/grid_view_01" />
 
</selector>