On Mon, Sep 26, 2011 at 4:33 PM, John Goche <[email protected]>wrote:
> Now I see what you mean. So these bundle objects are better than parcels to > pass things around. Still don't understand why parcelable isn't > working since my process was still around when I called it in some cases. > Not sure - but even if you figure that out, you'll run into the issue I described. Honestly, best to just forget about custom Parcelable types, IMO. > Anyways, besides designing parcelable as a performance improvement over > serializable I'm still puzzled by why the android team had to come up with > both bundles and parcels and not just have say bundles. > Good question. I'd love to hear on that as well. > Also, if an application has a unique context, then does a context > correspond to a process? I see context passed around as a parameter a lot, > but don't understand exactly what I am passing and why. It seems to me I > keep on passing the same thing around. Or does each activity have a > different context. Please help coming to grips with these presumably > simple concepts. > Each Activity *is* a different Context (see the inheritance hierarchy in the docs). What is it? The way I think about things named "context" (GL and GWT have the same concept) is "thingie that describes the environment you're running in, which provides and interface to that environment". On Android a Context is usually your primary gateway to the system APIs. It's more of an abstract concept than an true object. > Finally, I think as an alternative to using the Bundleable interface > described below I think it is also possible to pass parameters around by > storing them in an SQLite database since most applications will already have > one. Any disadvantages with this alternative approach (which at least should > work not only when the process is killed but also across reboots???) > I wouldn't call storing data in a database to retrieve later "passing parameters around". I wouldn't say "most applications already have one". If an developer needs one, they'll make one in their app. Primary disadvantage to this: I'd imaging saving to and reading from a DB will be considerably slower than putting that data in a Bundle. Not to mention the extra code to write to and read from the DB. There may also be concurrency considerations. Besides that, these are two fundamentally different concepts: marshalling data vs storing and persisting it. You could certainly use a DB to "pass data" around, but I'll bet you'll regret it later. ------------------------------------------------------------------------------------------------- TreKing <http://sites.google.com/site/rezmobileapps/treking> - Chicago transit tracking app for Android-powered devices -- 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
