How to load data to make them visible in an ActivityList?

I'm relatively new to Android and have the following question. I have a local DB on the device from which I want to display the content in an ActivityList. Let's say there is a table "person" on the DB containing general information like "name, surname etc." Every row in the table should be displayed as an item within the ActivityList.

I know that there exists a sort of Adapter with which I can directly fill the ActivityList with my table data, but is this the way to do it? Isn't it better to load all the data at startup and then hold them for the entire session and pass the data from one activity to another(or make them static..) if necessary, instead of loading the data every time I change to another Activity?

If I would have a normal Java application I would load the Data at startup and then just work with the loaded objects (at least for reasonable data sets).

Doesn't it make sense for an Android App too?开发者_如何学Python

I will up-rate every answer that makes sense to me.

Thanks! Slash

I would have a look at the ContentProvider.

You can use it to query your database and then show the content in the ListView using a CursorAdapter.

You need to use an Adapter if you want to work with ListView. So, that is a must. And you can set the Adapter data from your Activity.

As for the "sense" question, it probably makes sense. But as always it depends on a few things:

Will this data be used through out the application? Then it absolutely makes sense to load it once and use it everywhere. How you do that is up to your needs, static access or passing the data, all should work.

And DB access is always expensive. And if you have lots of rows, the loading process from the database can be extremely slow. So, again, load it once and use it everywhere is a good plan.

But be careful about blocking the UI thread when you load this data. You should never access DB from your UI thread. Instead use a worker thread or AsyncTask.