Button setonclicklistener error

Question

I am having a problem right now with setOnClickListener.

When i put this following line:

button.setOnClickListener(this);

Answer 1

Although it's been a long time, thought it might help others who have this problem, it took me many trials to get it right. But i think what finally solved my problem was setting the clickable attribute of a button in the layout's xml to true.
Code sample:

Further, if you would've looked at the DDMS perspective, you would've seen that the cause of the error was NullPointerException, which ofcourse was showing because clickable wasn't set. Correct me if i am wrong.