Depends.
If premature interruption of the long running operation could cause
data-corruption (e.g. uploading a large image on a remote server, for
example), yes you should use a service. Note that Android can kill
service-processes whenever it deems it necessary, or the user can
power-off the phone... But Android kills hidden activities much much
more aggressively than services.
If the long running operation is just to show something on a screen,
then i would just use a thread. The thread, along with the process,
could be restarted and the operation should work fine again (just
would take a little longer).
On Sep 30, 5:49 am, Kacper86 <cpph...@gmail.com> wrote:
> 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 <flyingdutc...@gmail.com> 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 <cpph...@gmail.com> 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 <broc.s...@gmail.com> 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 <cpph...@gmail.com> 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 <manojkumar.m...@gmail.com> 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 <cpph...@gmail.com> 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 -- Hide quoted text -
>
> - Show quoted text -
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