Put on the right the indicator of an ExpandableListView in Android

I don’t know a way to do that from XML but i’ll tell you a way to do so dynamically in your adapter.

First you have to remove group indicator from your xml

 <ExpandableListView [...] 
    android:groupIndicator="@null" />

Then in your layout of the parent add an imageview in the right position of your layout.

Then in your custom adapter do the following

public View getGroupView(int groupPosition, boolean isExpanded,
        View convertView, ViewGroup parent) {
  ...

    if (isExpanded) {
        groupHolder.img.setImageResource(R.drawable.group_down);
    } else {
        groupHolder.img.setImageResource(R.drawable.group_up);
    }
  ...

}