If you want to keep your thread running after you press the home or back button, i'm afraid you'd have to use a service.
When your activity is popped off the back-stack (e.g. pressing home), the OS could kill the process in which your activity is running and your thread will be terminated. As far as I know, there's no way around that. If you just want to keep the progress dialog up and running after keyboard changes and orientation changes, put the progress bar in a Dialog managed by the activity (showDialog(dialogID)). The activity then makes sure that the progress dialog is shown again after orientation change. On Sep 29, 3:11 am, Kacper86 <[email protected]> wrote: > hi! > > first of all, i have to admit that i was wrong. when you set > Dialog#setCancelable(false), hit home button, rerun your app, then > your progress dialog does not always work. so i'm still stuck :/ > > @Broc Seib: > thank you for your response! you said that you terminate your thread > when gui thread is dead. however i just want to do the opposite - i > want my thread to be alive while gui is gone. and when gui is > restarted, it should still be able to receive messages from running > thread. do know if that can be achieved without creating service with > thread and binding to it? > > On Sep 28, 4:43 am, Broc Seib <[email protected]> wrote: > > > > > I have built progress bars where I hay d a background thread that updated my > > Activity via callbacks (to do GUI updates in the UI thread). > > > I ended up using a WeakReference object to hold the callback pointer to my > > Activity. I have made the assumption (right or wrong) that my UI thread may > > be gone while my background thread still exists. I was experiencing some > > funky exceptions while testing my app -- I was rudely interrupting my > > application by pressing the back or home button in the middle of my > > background thread doing some non-GUI work. > > So when it is time for my background thread to report to my UI thread, if my > > WeakReference returns null, then I just silently exit my thread in the > > background, knowing my UI thread is gone. > > > Below is a canonical example demonstrating what I am doing. There may be > > more suitable solutions that I have not learned yet. > > -broc > > > package foo.example; > > > import java.lang.ref.WeakReference; > > > public class BackgroundThreadExample extends Thread { > > public interface Callback { > > public void onSomeBadEventUpdateGuiThread(Object stuff); > > public void onSomeGoodEventUpdateGuiThread(Object things); > > > } > > > private WeakReference<Callback> weakCallback; > > private Object stuffYouCareAbout; > > public BackgroundThreadExample(Callback callback, Object stuffYouCareAbout) > > { > > super("myThreadName"); > > this.weakCallback = new WeakReference<Callback>(callback); > > this.stuffYouCareAbout = stuffYouCareAbout;} > > > �...@override > > public void run() { > > // do background stuff > > boolean isGood = doStuff(this.stuffYouCareAbout); > > try { > > // inform our UI via callback. > > if ( isGood ) { > > getCallback().onSomeGoodEventUpdateGuiThread("was good");} else { > > > getCallback().onSomeBadEventUpdateGuiThread("was bad");} > > } > > > catch (MyWeakRefException e) { > > // our UI thread object is gone. bummer. > > // silently fall thru to exit this thread. > > > } > > } > > > private boolean doStuff(Object stuffYouCareAbout) { > > // some useful stuff might go here. > > return true;} > > > private Callback getCallback() throws MyWeakRefException { > > Callback callback = weakCallback.get(); > > if ( callback == null ) { > > throw new MyWeakRefException(); > > > } else { > > return callback; > > } > > } > > } > > On Sat, Sep 26, 2009 at 8:17 PM, Kacper86 <[email protected]> wrote: > > > > Thank you for your response! It works great - now I can change the > > > orientation and the ProgressDialog works. And do have any ideas how to > > > solve the problem with user hitting "back" or "home" button? I found > > > that you may set your Dialog with Dialog#setCancelable(false). Then, > > > the user can only hit "home" button, and when he launches the app > > > again, ProgressDialog is still there! > > > > However, what should be done if I want Dialog that can be cancelable? > > > So that the user can cancel ProgressDialog, set something in the app > > > settings, hit "home" button, run sth else, and then relaunch my app to > > > check the progress? > > > > On Sep 26, 11:36 am, manoj <[email protected]> wrote: > > > > You need to implement the method > > > > public void onConfigurationChanged(Configuration arg0) > > > > { > > > > super.onConfigurationChanged(arg0); > > > > } > > > > > in your activity. and in manifest file, you have to the statement > > > > android:configChanges="keyboardHidden|orientation" for that activity. > > > > > so when your screen orientation is changed, it wont call the onCreate > > > > () method again. > > > > > On Sep 26, 1:21 pm, Kacper86 <[email protected]> wrote: > > > > > > Hi! > > > > > > I've created ProgressDialog with a second thread according to the > > > > > DevGuide: > > > >http://developer.android.com/guide/topics/ui/dialogs.html#ProgressDialog > > > > > It works great till user: > > > > > > 1) changes screen orientation or > > > > > 2) hits the back button twice (first to hide the dialog, second to > > > > > hide the app) to hide the application and run the app again after a > > > > > while. > > > > > > Then, onCreate() is called (for the second time), and progress bar > > > > > stops responding properly. My thread may work for a few minutes and I > > > > > want to give the user possibility to hide it and do sth else. After a > > > > > while he might want to run the app again in order to check the > > > > > progress. > > > > > > I found a few articles concerning this topic, but I couldn't find the > > > > > exact solution I should chose for this problem. So, could you tell mi > > > > > what is the proper way to handle this? Should i save the handler and > > > > > dialog state with "onRetainNonConfigurationInstance()"? If so, how to > > > > > do it properly and is it safe? > > > > > > Or maybe my solution is wrong and I should create service, which > > > > > spawns the thread and communicates with activity (progress bar) with > > > > > AIDL? But this will mean that the article in DevGuide is wrong, cause > > > > > it doesn't give a long term solution for creating a progress bar... > > > > > > I'm stuck, and I'd appreciate all the response!- Hide quoted text - > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -~----------~----~----~----~------~----~------~--~---
