now i use the code above to control the map.
i want to handle the event when user zoom in or zoom out the map by the controls provided.
how can i get the event, then i will get the mapCenter and the latitudeSpan and longitudeSpan.?

hi tanran,

i just released a new library that addresses to your needs.
check out: http://code.google.com/p/mapview-overlay-manager/

would be great if you give me some feedback