问题
At zoom levels not included in my map cache, generated by MapTiler, Android Maps v2 does not display the map. My understanding was that Android Maps v2 will use the highest zoom level available for a given tile cache, so why is it hiding the layer?
On closer inspection, it's because the tile provider I've implemented returns null, indicating no tile available. Android Maps v2 doesn't seem to hold onto the lower resolution copy and display it, instead just opting to show nothing.
回答1:
This is expected behavior. If you don't like it, you may post a feature request on gmaps-api-issues. I have a feeling it won't be implemented, because the tiles would look ugly.
来源：https://stackoverflow.com/questions/17712898/android-maps-v2-custom-overlay-disappears-on-zoom