I have implemented some computationaly heavy functions into my application. Depending on the type of input it can take up to several minutes for a thread to return. During this time, I want the user to be able to work with other activities to perform different tasks (i.e. prepare data for the next run). Then, after the Service has finished it’s computations, the user should be notified with a Toast that the result is ready and that he should check back to the Activity he started the Service in. Unfortunately I’m stuck at this point.
Is it possible to somehow communicate with an Activity which is destroyed at the moment? Like modifying the saved state, so that when it get’s recreated the result will be displayed. The only way of communication I did find was via broadcasting from the Service, but this requires the Activity to listen, which is not possible as it doesn’t exist at the moment the Service finishes.
The only solution that occured to me was writing a file when the Service is finished and then trying to read it in the Activity, but I would prefer not to work with the file system if that’s possible.
Am I missing something here or thinking in the wrong direction?
use Asynctask
http://developer.android.com/reference/android/os/AsyncTask.html