Android SharedPreferences in Fragment

问题:

I am trying to read SharedPreferences inside Fragment. My code is what I use to get preferences in any other Activity.

     SharedPreferences preferences = getSharedPreferences("pref", 0);

I get error

    Cannot make a static reference to the non-static method getSharedPreferences(String, int) from the type ContextWrapper    

I have tried to follow these links but with no luck Accessing SharedPreferences through static methods and Static SharedPreferences. Thank you for any solution.

回答1:

The method getSharedPreferences is a method of the Context object, so just calling getSharedPreferences from a Fragment will not work...because it is not a Context! (Activity is an extension of Context, so we can call getSharedPreferences from it).

So you have to get your applications Context by

// this = your fragment
SharedPreferences preferences = this.getActivity().getSharedPreferences("pref", Context.MODE_PRIVATE);

回答2:

The marked answer didn't work for me, I had to use

SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getActivity());

EDIT:

Or just try removing the this:

SharedPreferences prefs = getActivity().getSharedPreferences("pref", Context.MODE_PRIVATE);

回答3:

As a note of caution this answer provided by the user above me is correct.

SharedPreferences preferences = this.getActivity().getSharedPreferences("pref",0);

However, if you attempt to get anything in the fragment before onAttach is called getActivity() will return null.

回答4:

You can make the SharedPrefences in onAttach method of fragment like this:

@Override
public void onAttach(Context context) {
    super.onAttach(context);
    SharedPreferences preferences = context.getSharedPreferences("pref", 0);
}

回答5:

This did the trick for me

SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getContext());

Check here https://developer.android.com/guide/topics/ui/settings.html#ReadingPrefs

回答6:

getActivity() and onAttach() didnot help me in same situation
maybe I did something wrong
but! I found another decision
I have created a field Context thisContext inside my Fragment
And got a current context from method onCreateView
and now I can work with shared pref from fragment

public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {   
...   
thisContext = container.getContext();   
...   
}