AsyncTaskLoader vs AsyncTask

OKA picture OKA · Aug 19, 2011 · Viewed 49.9k times · Source

Since Honeycomb and the v4 Compatibility Library it is possible to use AsyncTaskLoader. From what I understand, the AsyncTaskLoader can survive through config changes like screen flips.

Is it recommended to use AsyncTaskLoader instead of AsyncTask? Does LoaderManager get in the picture too?

But I haven't found any good example(s) about how to correctly use the AsyncTaskLoader. The docs also provide no examples. Can anyone provide some good examples.

Answer

Nikolay Elenkov picture Nikolay Elenkov · Aug 19, 2011

You can have a look at the compatibility library's source code to get more info. What a FragmentActivity does is:

  • keep a list of LoaderManager's
  • make sure they don't get destroyed when you flip your phone (or another configuration change occurs) by saving instances using onRetainNonConfigurationInstance()
  • kick the right loader when you call initLoader() in your Activity

You need to use the LoaderManager to interface with the loaders, and provide the needed callbacks to create your loader(s) and populate your views with the data they return.

Generally it should be easier than managing AsyncTask's yourself. However, AsyncTaskLoader is not exactly well documented, so you should study the example in the docs and/or model your code after CursorLoader.