On Wed, Mar 4, 2009 at 2:41 PM, Chronos <g358279012044...@gmail.com> wrote: > > Thanks for the idea - but this is not my problem: the result sent is > the result I set in the onCreate method (a default result); if I fail > to do this, I will get a java.lang.NullPointerException, which > underlines my point - setResult() in onPause() is too late; my > activity is not cancelled either - I always get an Activity.RESULT_OK.
You should set the result when your child activity is about to exit - for example I set the result from my child activity when a button is clicked and just before exiting it, e.g.: // in a button click handler setResult(...); finish(); The documentation for Activity mentions that "When an activity exits, it can call setResult(int) to return data back to its parent." When you're getting a NPE what does you stacktrace look like? > > Do you think, onPause() is the correct point to setResult() ? It seems > to me, that the result has already been transmitted in some > communication queue at this point - all calls to setResult() are in > vain. btw, you shouldn't assume that the parent activity will outlive the child one - that is, the fact that your parent activity has spawned another one for result doesn't mean it won't be destroyed should the system need to destroy it because it's not in the foreground. > > > On Mar 4, 12:39 pm, Stoyan Damov <stoyan.da...@gmail.com> wrote: >> Actually read >> carefullyhttp://developer.android.com/reference/android/app/Activity.html#star...) >> >> On Wed, Mar 4, 2009 at 1:31 PM, Stoyan Damov <stoyan.da...@gmail.com> wrote: >> > Re: >> >> > - setResult() in client.onPause() is called TOO LATE; the result has >> > already been transmitted to the parent (although the method >> > client.onPause() seems to be called in time). >> >> > If the result has been already set, this means that the result value >> > is CANCELLED immediately after your child activity started. >> > Read carefully about the launchMode property - >> >http://developer.android.com/guide/topics/manifest/activity-element.h... >> >> > Cheers >> >> > On Wed, Mar 4, 2009 at 12:59 PM,Chronos<g358279012044...@gmail.com> wrote: >> >> >> Hello there ;) >> >> >> I have some - maybe simple - problem; unfortunately I cannot find a >> >> solution: >> >> >> I have two activities which communicate via: startActivityForResult(), >> >> setResult(), onActivityResult. I will call the first activity "parent" >> >> and the second one "client", although this may not be technically >> >> correct; so the order of calls must be: >> >> >> parent.startActivityForResult() >> >> client.setResult() >> >> parent.onActivityResult() >> >> >> Now, where should I call setResult in the client activity ? >> >> >> I have already tried various possibilities which have all failed: >> >> >> - setResult() in client.onPause() is called TOO LATE; the result has >> >> already been transmitted to the parent (although the method >> >> client.onPause() seems to be called in time). >> >> - client.onSaveInstanceState() is not guaranteed to be called at all >> >> (and the documentation hints at the same timing problem). >> >> - The only TECHNICALLY POSSIBLE solution seems to implement a change- >> >> listener for any screen element and set the result there. This may >> >> work in theory, but is NOT VIABLE in practice: (1) it is strenuous and >> >> error-prone for activities with many elements; (2) it gets even more >> >> complicated, when side-effects kick in (change one field in dependency >> >> to another); (3) it is really slow, since one must write ALL contents >> >> any time, a SINGLE element changes (and the generic Intent >> >> communication is already slow by design). >> >> >> To me, it would seem most natural to overload the onPause() method and >> >> setResult() there - once and for all. There MUST be some easier way >> >> than implementing zounds of listeners ... >> >> >> Am I overlooking something ? Another listener I haven't stumbled over >> >> yet ? Please prove me wrong ;) > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
