Change View content in activity dynamically

Question

My abstract class extended from Activity class consists of three Views as described in the following XML snippet:

Answer 1

First change the view in your main layout into a view group (for example, a LinearLayout). Then you can add views to it. If you add a unique view, it will have exactly the effect you want to achieve.

class OneActivity extends MyActivity {
   @Override
   protected void initializeContent() {
      final ViewGroup viewGroup = (ViewGroup) findViewById(R.id.activity_content);
      viewGroup.addView(View.inflate(this, R.layout.some_view, null)); 
   }
}

In your case that should work. If your custom view group contained other views from higher up in the hierarchy, you can clean it before adding your custom view:

viewGroup.removeAllViews();

It works, I do exactly that in most of my projects.

An alternative is to look at the Fragments API, available for latest versions of the SDK.