get value of a checkbox in another fragment : I would like to get the value of my checkbox that is in my confiFragment and get that value in MainActivity . 
the configFragment is related to the confiActivity. 

I tried this method but i get a null ; can someone help me please? 

this is my fragment: 

    public class configFragment extends android.support.v4.app.Fragment {
        CheckBox check;
        configActivity cmt;
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.config_layout, container, false);
            check = (CheckBox) rootView.findViewById(R.id.checkbox1);
            TextView text1=(TextView) rootView.findViewById(R.id.text1);
            text1.setText("hello ");
    
            cmt=(configActivity) getActivity();
            check.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    if(check.isChecked()){
    
                        Log.d("status","checked");
                        //check.setChecked(true);
                        cmt.checking=true;
    
                    }else{
                        Log.d("status","not checked");
                        //check.setChecked(false);
                    cmt.checking=false;
                    }
                }
            });
    
            //cmt.checking=load();
    
    
    
    
    
    
            //  check();
            return rootView;
        }
    
    
        @Override
        public void onPause() {
            super.onPause();
            save(check.isChecked());
        }
    
        @Override
        public void onResume() {
            super.onResume();
            check.setChecked(load());
        }
    
        private void save(final boolean isChecked) {
            SharedPreferences sharedPreferences = getActivity().getPreferences(Context.MODE_PRIVATE);
            SharedPreferences.Editor editor = sharedPreferences.edit();
            editor.putBoolean("check", isChecked);
            editor.commit();
        }
    
        public boolean load() {
            SharedPreferences sharedPreferences = getActivity().getPreferences(Context.MODE_PRIVATE);
            return sharedPreferences.getBoolean("check", check.isChecked());
        }

    }
 and this is the activity of this fragment: 

    public class configActivity extends SingleFragmentActivity {

    public Boolean checking;

    @Override
    protected Fragment createFragment()
    {
        return new configFragment();
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        configFragment cf=new configFragment();
        SharedPreferences sharedPreferences = this.getPreferences(Context.MODE_PRIVATE);
        checking=sharedPreferences.getBoolean("check", cf.check.isChecked());
    }
}

and this is my main activity :

    public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        TextView hello=(TextView) findViewById(R.id.hello);
        Button but1=(Button) findViewById(R.id.button1);


        but1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent i=new Intent(MainActivity.this,configActivity.class);
                startActivity(i);

            }
        });

        hello.setText("Hello world");
       configActivity config=new configActivity();
        Log.d("status of checking",config.checking.toString());
        if(config.checking=true){
            Log.d("checked","true");
        }else{
            Log.d("not checked","false");
        }



    }



