Thanks a lot guys for the information, I found this article http://peacemoon.wordpress.com/2009/08/23/android-developing-orientation-aware-android-applications/ I need to save many objects so basically onSavedInstanceState is not of full use . So i am going forward with onRetainNonConfigurationInstance(). @Charlie, why is this method not so reliable? Thanks, Alok. On Fri, May 14, 2010 at 6:25 AM, Charlie Collins <charlie.coll...@gmail.com>wrote:
> http://developer.android.com/intl/de/guide/topics/fundamentals.html#actlife > > "Saving activity state > > When the system, rather than the user, shuts down an activity to > conserve memory, the user may expect to return to the activity and > find it in its previous state. > > To capture that state before the activity is killed, you can implement > an onSaveInstanceState() method for the activity. Android calls this > method before making the activity vulnerable to being destroyed — that > is, before onPause() is called. It passes the method a Bundle object > where you can record the dynamic state of the activity as name-value > pairs. When the activity is again started, the Bundle is passed both > to onCreate() and to a method that's called after onStart(), > onRestoreInstanceState(), so that either or both of them can recreate > the captured state. > > Unlike onPause() and the other methods discussed earlier, > onSaveInstanceState() and onRestoreInstanceState() are not lifecycle > methods. They are not always called. For example, Android calls > onSaveInstanceState() before the activity becomes vulnerable to being > destroyed by the system, but does not bother calling it when the > instance is actually being destroyed by a user action (such as > pressing the BACK key). In that case, the user won't expect to return > to the activity, so there's no reason to save its state. > > Because onSaveInstanceState() is not always called, you should use it > only to record the transient state of the activity, not to store > persistent data. Use onPause() for that purpose instead." > > http://developer.android.com/intl/de/reference/android/app/Activity.html > > "Configuration Changes > If the configuration of the device (as defined by the > Resources.Configuration class) changes, then anything displaying a > user interface will need to update to match that configuration. > Because Activity is the primary mechanism for interacting with the > user, it includes special support for handling configuration changes. > > Unless you specify otherwise, a configuration change (such as a change > in screen orientation, language, input devices, etc) will cause your > current activity to be destroyed, going through the normal activity > lifecycle process of onPause(), onStop(), and onDestroy() as > appropriate. If the activity had been in the foreground or visible to > the user, once onDestroy() is called in that instance then a new > instance of the activity will be created, with whatever > savedInstanceState the previous instance had generated from > onSaveInstanceState(Bundle). > > This is done because any application resource, including layout files, > can change based on any configuration value. Thus the only safe way to > handle a configuration change is to re-retrieve all resources, > including layouts, drawables, and strings. Because activities must > already know how to save their state and re-create themselves from > that state, this is a convenient way to have an activity restart > itself with a new configuration. > > In some special cases, you may want to bypass restarting of your > activity based on one or more types of configuration changes. This is > done with the android:configChanges attribute in its manifest. For any > types of configuration changes you say that you handle there, you will > receive a call to your current activity's > onConfigurationChanged(Configuration) method instead of being > restarted. If a configuration change involves any that you do not > handle, however, the activity will still be restarted and > onConfigurationChanged(Configuration) will not be called." > > That should get you going in the right direction. There is also > onRetainNonConfigurationInstance (Activity method) but it's not what > you should rely on (can be used to optimize), but the basics are the > onSaveInstanceState and onRestoreInstanceState methods. > > > On May 13, 4:29 am, Alok Kulkarni <kulsu...@gmail.com> wrote: > > I am having an application showing ListItems and Dialog boxes in it.. > > I want that when i change the orientation from Portrait to landscape > mode, i > > need to maintain the state of the application .. I have seperate XMLs for > > landscape and portrait mode.. > > What is the best way to achieve this > > > Thanks , > > Alok. > > > > -- > > 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<android-developers%2bunsubscr...@googlegroups.com> > > For more options, visit this group athttp:// > groups.google.com/group/android-developers?hl=en > > -- > 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<android-developers%2bunsubscr...@googlegroups.com> > For more options, visit this group at > http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups "Android Developers" group. 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