You create a CursorLoader
within a loader framework. To set up the framework, you implement theLoaderCallbacks<Cursor>
as part of an
Activity
. In addition, to provide compatibility compatible with platform versions starting with Android 1.6, you must extend theActivity
with the
FragmentActivity
class. http://blog.csdn.net/sergeycao
Note: A Fragment
is not a prerequisite forCursorLoader
. As a convenience, the support library classFragmentActivity
contains the fragment and
the loader frameworks, but they are completely independent of each other.
Before you can use the loader framework, you need to initialize it. To do this, retrieve aLoaderManager
object and call its
initLoader()
method.
If you do use one or more Fragment
objects in an
, the
ActivityLoaderManager
you retrieve is available to all of them.
Extend an Activity
To set up an Activity
subclass to contain a
, extend the subclass with must extend
CursorLoaderFragmentActivity
, which provides the loader framework, and implement theLoaderCallbacks<Cursor>
interface, which specifies method
signatures that the loader framework uses to interact with theActivity
.
For example:
public class DisplayActivity extends FragmentActivity implements LoaderManager.LoaderCallbacks<Cursor>
Retrieve a LoaderManager
To get an instance LoaderManager
for use in your
, call
ActivityFragmentActivity.getSupportLoaderManager()
at the beginning of theonCreate()
method. For example:
private LoaderManager mLoaderManager; public void onCreate() { ... mLoaderManager = this.getSupportLoaderManager();
Initialize the Loader Framework
Once you have the LoaderManager
object, initialize it by callinginitLoader()
. For example:
// CursorLoader instance identifier public static final int URL_LOADER = 0; ... // Initializes the CursorLoader getSupportLoaderManager().initLoader(URL_LOADER, null, this);