Using context in a fragment

Question

How can I get the context in a fragment?

I need to use my database whose constructor takes in the context, but getApplicationContext() and FragmentClass.this don't work so what can I do?

Database constructor

public Database(Context ctx)
{
    this.context = ctx;
    DBHelper = new DatabaseHelper(context);
}

Answer 1

public class MenuFragment extends Fragment implements View.OnClickListener {
    private Context mContext;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        FragmentMenuBinding binding=FragmentMenuBinding.inflate(inflater,container,false);
        View view=binding.getRoot();
        mContext=view.getContext();
        return view;
    }
}

Answer 2

You can use getActivity(), which returns the activity associated with a fragment.
The activity is a context (since Activity extends Context).

Answer 3

Since API level 23 there is getContext() but if you want to support older versions you can use getActivity().getApplicationContext() while I still recommend using the support version of Fragment which is android.support.v4.app.Fragment.

Answer 4

I need context for using arrayAdapter IN fragment, when I was using getActivity error occurs but when i replace it with getContext it works for me

listView LV=getView().findViewById(R.id.listOFsensors);
LV.setAdapter(new ArrayAdapter<String>(getContext(),android.R.layout.simple_list_item_1 ,listSensorType));

Answer 5

You can use getActivity() or getContext in Fragment.

Documentation

/**
 * Return the {@link FragmentActivity} this fragment is currently associated with.
 * May return {@code null} if the fragment is associated with a {@link Context}
 * instead.
 *
 * @see #requireActivity()
 */
@Nullable
final public FragmentActivity getActivity() {
    return mHost == null ? null : (FragmentActivity) mHost.getActivity();
}

and

 /**
     * Return the {@link Context} this fragment is currently associated with.
     *
     * @see #requireContext()
     */
    @Nullable
    public Context getContext() {
        return mHost == null ? null : mHost.getContext();
    }

Pro tip

Check always if(getActivity!=null) because it can be null when fragment is not attached to activity. Sometimes doing long operation in fragment (like fetching data from rest api) takes some time. and if user navigate to another fragment. Then getActivity will be null. And you will get NPE if you did not handle it.

Answer 6

Previously I'm using onAttach (Activity activity) to get context in Fragment

Problem

The onAttach (Activity activity) method was deprecated in API level 23.

Solution

Now to get context in Fragment we can use onAttach (Context context)

onAttach (Context context)

• Called when a fragment is first attached to its context. onCreate(Bundle) will be called after this.

Documentation

/**
 * Called when a fragment is first attached to its context.
 * {@link #onCreate(Bundle)} will be called after this.
 */
@CallSuper
public void onAttach(Context context) {
    mCalled = true;
    final Activity hostActivity = mHost == null ? null : mHost.getActivity();
    if (hostActivity != null) {
        mCalled = false;
        onAttach(hostActivity);
    }
}

SAMPLE CODE

public class FirstFragment extends Fragment {


    private Context mContext;
    public FirstFragment() {
        // Required empty public constructor
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        mContext=context;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rooView=inflater.inflate(R.layout.fragment_first, container, false);

        Toast.makeText(mContext, "THIS IS SAMPLE TOAST", Toast.LENGTH_SHORT).show();
        // Inflate the layout for this fragment
        return rooView;
    }

}

NOTE

We can also use getActivity() to get context in Fragments but getActivity() can return null if the your fragment is not currently attached to a parent activity,