addView(View) is not supported in AdapterView

You are trying to set it to your ListView. That's not going to work. Try setting it to it's parent. With something like

listContacts.getParent().addView(aux);

Edit after comments

To add an item to your ListView you need to add it to whatever list you use to populate your ListView and call setAdapter() on it or notifyDataSetChanged() on your Adapter.

You don't add items to your ListView. You add items to your Adapter and set the Adapter on the ListView.

I suggest going through this tutorial

and reading through the docs thoroughly.

ListView

Adapter

From the docs

An Adapter object acts as a bridge between an AdapterView and the underlying data for that view. The Adapter provides access to the data items. The Adapter is also responsible for making a View for each item in the data set.

Your ListView is the AdapterView here (it could be a Spinner or other such things)