I'm guessing that your first background task was running the whole time, and when you restarted your application you got a new instance of the activity, and probably you created a new instance of the background task so now you have two tasks running. The old activity is not accessible to you anymore, and perhaps there's something else in your background task that you're not showing, (in the part that updates progress perhaps?) that is trying to access something that's just not there.
If your application stays alive but the activity is re-created, you need some way to re-establish a connection between your new activity and your old background task. Firing up a second task is not what you want to do. You could check out onRetainNonConfigurationChange() and getLastNonConfigurationInstance() as one possible way to hang on to the background task between activities, or you might want to keep a pointer to the background task in your application context. Your code in the background task that updates the activity needs to know when the activity has gone away and when you get a new one. Or you could put something in the background task to kill it off when the activity goes away, like calling a method within the activity's onDestroy() to tell your task class to wrap it up and stop. - dave www.androidbook.com On Oct 23, 6:45 am, Mark Murphy <mmur...@commonsware.com> wrote: > On Sat, Oct 23, 2010 at 4:57 AM, chcat <vlyamt...@gmail.com> wrote: > > I have activity class running infinite loop in BackgroundAsyncTask > > The AsyncTask is designed for a "task", something that will run for a > short while and end. If you want a long-running background thread, I > recommend you fork your own thread. > > > I have a problem trying to "finish" this activity, when i press > > "btnClose" the activity window disappears > > Please let the user exit the activity using the BACK button. There is > no need to have a separate UI widget for this. > > > Any idea where is null pointer exception coming from and how to do it > > right? > > Based on the code that you posted, your socket is null, because you > never open one. > > -- > Mark Murphy (a Commons > Guy)http://commonsware.com|http://github.com/commonsguyhttp://commonsware.com/blog|http://twitter.com/commonsguy > > Android 2.2 Programming Books:http://commonsware.com/books -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
