I'm developing a simple app with a customized background and a button in the middle. I've got the whole different resolutions for different screens down, but do all the versions of the background need to be 9patches? How do I take into consideration the always there android top navigation bar and the possible use of advertisements at the bottom? Do they just cover the design or do they change the resolution?
I've got the whole different resolutions for different screens down that's not how it works on android. see this:
do all the versions of the background need to be 9patches? no . you decide . normally, buttons and views use the 9 patch images, but it can be useful for many other things. more info:
How do I take into consideration the always there android top navigation bar and the possible use of advertisements at the bottom?
you can put a linear layout which has the ad on the bottom , and once it will be shown , the upper view will shrink its size. about the action bar on the top, it doesn't matter , since the layout is below it anyway. if you wish, you can also hide the top bar. however , if you have the bottom navigation bar (as on honeycomb and some ice-cream sandwich devices ) , you can't just hide it , since the end user must be able to press the back and home buttons .
Do they just cover the design or do they change the resolution?
you (and also those components) can't change resolution just like on a PC . everything takes space depending on your code and layout.
it seems that you need some guidelines of how to design for android. may i suggest checking out those links: