getContext() method returns null in fragment. Is it a good idea to keep the context in a variable? I want to understand the pros and cons

Question

What I do is

Approach 1:

public View onCreateView(.....){
     context = getContext();
}

I am using this context object wherever I need. Is this the right approach or I should use getContext != null and use the value returned by getContext(). Also I understand that I can get the context from getActivity() but it will also return null if 'getContext()' is returning null.

As an alternative I can do this every time I need the context.

Approach 2:

if(getActivity() != null){
      //use getActivity() here
}

I want to understand which one is a better way and why?

Answer 1

In your fragment override the function

private Context mContext;

@override
void onAttach(Context context) {
    mContext = context;
}

This is how you’ll get context in fragment as it is never recommended to pass context to fragments and adapters from activities.

Answer 2

getActivity() and getContext() both will return null if your fragment is not attached to an activity/context. If they are returning null, I won't suggest using any previously stored value as the stored context may have been detached and can lead to memory leaks.

Generally, you get a context after the fragment is attached. You can store the context in the onAttach(Context) callback.

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

However, be sure to set it to null whenever the fragment gets detached to avoid memory leaks.

@Override
public void onDetach() {
    this.activity = null;
    super.onDetach();
}

There are no cons of storing the context in a variable that I can think of except you need to be careful about fragment state changes. The onDetach() call takes care of that.

Answer 3

Well, if you need to get context and keep it, i recommend create a static variable on your current activity (if you only use one activity)

//if use only one Activity
private static Context context;
public static Context getRunningContext() {
    return context;
}
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ...
    this.context=getApplicationContext();
}

or use getActivity() instead.

    Context context;
   public View onCreateView(.....){
   context = getActivity();
}