What is the difference between getView() and getActivity()?

问题

What is the difference between getView() and getActivity()?

I have used both methods but don't understand the basic difference even methodology of usage are also same in android:

ListView deliverItemList = (ListView) getView().findViewById(R.id.load_item_list);
ListView deliverItemList = (ListView) getActivity().findViewById(R.id.load_item_list);

I have assumed that getView() may produce NullPointerException, share your knowledge with me and which method is recommended?

回答1:

getActivity() returns the Activity hosting the Fragment, while getView() returns the view you inflated and returned by onCreateView. The latter returns a value != null only after onCreateView returns

回答2:

From android docs:

getActivity() returns the Activity this fragment is currently associated with, and getView() returns the root view for the fragment's layout (the one returned by onCreateView(LayoutInflater, ViewGroup, Bundle)), if provided.

So, in your case, by the following line of code:

getView().findViewById(R.id.load_item_list);

you are searching for the view in your fragment, but using the following line of code:

getActivity().findViewById(R.id.load_item_list);

you are searching for the view in your activity hosting your fragment.

About your question of which one to use, it depends. If you are trying to inflate fragment, you need to inflate your xml in onCreateView, and using that inflated view you search for your views like this:

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.your_layout, container, false);
    ListView lv = (ListView)v.findViewById(R.id.view_id);
}

来源：https://stackoverflow.com/questions/32501792/what-is-the-difference-between-getview-and-getactivity