posted 7 years ago
The back button can always cause issues. Similarly, turning the phone on it's side and putting it in the background. In all these cases you need to be able to determine the current state and decide if the application should continue from where it left off, restart, or not do anything at all.
The first step is to determine the state. So, if you are taking three pictures, you need to know two things: 1) That it is taking pictures. 2) Which picture it is up to.
When the user hits the back button, what happens? If the Activity changes, everything should stop. But if you are capturing the button, you can decide what to do based on the current state.