I found a tutorial to create android custom button :
http://developer.android.com/resources/tutorials/views/hello-formstuff.html#CustomButton
What is the differences between pressed and focused
And please tell me a focused condition on this button. because I couldn’t find any condition which can make this button turned orange.
You can focus buttons without clicking them. This was a bug in a application i developed recently. I set them to be focusable: then the first click on them was just focusing the user on the button and the second was actually triggering the onClick event. This is not so good user experience, but I imagine there might be cases where this is useful.