AndEngine Onscreen controls

I wish to create Onscreen controls in my game, but i don't how to create Onscreen controls.

My开发者_Go百科 doubts are:

1. How to create OnScreen Control?
2. Where should the OnScreen Controls be implemented in our game project?
3. Types of OnScreen Controls?

Now I am creating this game. I have one ball but I wish to create Left, Right, Up and Down move activities. which controls are suitable for this game?

Check

AnalogOnScreenControlExample.java here

Or

DigitalOnScreenControlExample.java here