Difference between onKey(), OnKeyDown() and dispatchKeyEvent() methods provided by Android?

Question

What is the difference between onKey(), OnKeyDown() and dispatchKeyEvent() methods provided by Android?
I Would like to know when and where each of these can be used.

Answer 1

DispatchKeyEvent Hardware key events are always delivered to the View currently in focus. They are dispatched starting from the top of the View hierarchy, and then down, until they reach the appropriate destination. If your View (or a child of your View) currently has focus, then you can see the event travel through the dispatchKeyEvent() method. In short, dispatchKeyEvent() will be only called if TextView/EditText is in focus.

onKeyDown Called when a key was pressed down and not handled by any of the views inside of the activity