I hesitate to raise a word against any of Dianne's advice (ever) - and it clearly depends on the nature of your application. But what I find with my code is that most of the global state I want to keep depends on a Context. For example, anything that loads resources, or anything that needs to generate user readable messages. As a consequence I end up with a number of 'helper' classes that hold a reference to a context so that they can do their work. I find that the Application instance is the obvious context for these helpers.
Furthermore, a specialization of the Application class seems the natural place for application code to access these objects, since the Application can instantiate them with itself (eagerly in onCreate or lazily behind accessors). Tom 2009/9/11 Dianne Hackborn <[email protected]> > On Fri, Sep 11, 2009 at 8:10 AM, Mark Murphy <[email protected]>wrote: > >> The four main options I have used are: >> >> 1. Custom application class, like you are proposing >> >> 2. Static data (e.g., singleton class instance holding your configuration) >> >> 3. A service >> >> 4. Shared preferences >> >> "Best" is somewhat subjective -- I certainly do not have a definitive >> "always use X" recommendation. >> > > There isn't a best, it's very much dependent on what semantics you want -- > shared preferences will remain after the process is gone, a service's state > is tied to the process but tells the system to try to keep the process > around, and Application and static data are tied directly to the lifetime of > the process and allow the system to remove them without guilt when the > process isn't in active use. (So Application and static are redundant, and > static data lets you better modularize your code instead of stuffing > everything in to Application, which is why I recommend statics.) > > -- > Dianne Hackborn > Android framework engineer > [email protected] > > Note: please don't send private questions to me, as I don't have time to > provide private support, and so won't reply to such e-mails. All such > questions should be posted on public forums, where I and others can see and > answer them. > > > > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
