If I have a long running operation should i spawn a new thread or create new service with different process id (without creating new thread)? Because I'm not sure I understand the difference, despite the fact I read a lot of information concerning the subject.
On Sep 29, 4:32 pm, Streets Of Boston <[email protected]> wrote: > 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 -~----------~----~----~----~------~----~------~--~---
