Attempt to invoke virtual method on a null object reference

Question

I try to call Fragment method from Activity. Need to set text t1..t6 (which are in fragment.xml) from activity. So there is an error

FATAL EXCEPTION: java.lang.NullPointerException: Attempt to invoke virtual method 'void PageFragment.setTime(java.lang.String)' on a null object reference.

PageFragment.java

public class PageFragment extends Fragment {

        static final String ARGUMENT_PAGE_NUMBER = "arg_page_number";
        TextView t1,t2,t3,t4,t5,t6;
        int pageNumber;

        static PageFragment newInstance(int page) {
            PageFragment pageFragment = new PageFragment();
            Bundle arguments = new Bundle();
            arguments.putInt(ARGUMENT_PAGE_NUMBER, page);

            pageFragment.setArguments(arguments);
            return pageFragment;
        }

        @Override
        public void onAttach(Activity activity) {
            super.onAttach(activity);   
        }

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            pageNumber = getArguments().getInt(ARGUMENT_PAGE_NUMBER);
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            View view = inflater.inflate(R.layout.fragment, null);
            t1=(TextView)view.findViewById(R.id.t1);
            t2=(TextView)view.findViewById(R.id.t2);
            t3=(TextView)view.findViewById(R.id.t3);
            t4=(TextView)view.findViewById(R.id.t4);
            t5=(TextView)view.findViewById(R.id.t5);
            t6=(TextView)view.findViewById(R.id.t6);
            return view;
        }

        public void setTime(String a){
            t1.setText(a);
        }
    }

Schedule.java

FragmentManager fm = getSupportFragmentManager();
PageFragment fragment =(PageFragment)fm.findFragmentById(R.id.RelativeLayout1);
fragment.setTime((input1.getText().toString()));

You class are extending Fragment. `onCreate` method is not needed. — John Joe, May 17 '17 at 15:15

John Joe · Answer 1 · 2017-05-17T15:30:13.507

0

The way you are trying to pass data to fragment is wrong.This is the correct way

Schedule.java

 Bundle bundle = new Bundle();
 bundle.putString("arg_page_number", input1.getText().toString());
 // set Fragmentclass Arguments
 PageFragment fragobj = new PageFragment();
 fragobj.setArguments(bundle);

PageFragment.java

Receive data inside fragment onCreateView method

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
     View view = inflater.inflate(R.layout.fragment, null);
     pageNumber = getArguments().getInt(ARGUMENT_PAGE_NUMBER,0);
     t1=(TextView)view.findViewById(R.id.t1);
     t2=(TextView)view.findViewById(R.id.t2);
               .......           
    return view;
   }

Again, you are extending your class to Fragment. OnCreate method is not needed.

edited May 17 '17 at 15:30

answered May 17 '17 at 15:22

John Joe

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public void setTime(String a){ t1.setText(a); } this method doesnt work, need to set text t1 – Oleg May 17 '17 at 15:30
can you explain what you trying to achieve ? – John Joe May 17 '17 at 15:31
Why you need this line `fragment.setTime((input1.getText().toString()));` ? Pass to fragment ? – John Joe May 17 '17 at 15:34
So i need to initialize t1..t6(TextView) from activity, but still cant do it. Yes, I think i need to pass to fragment. – Oleg May 17 '17 at 18:35
Thank you for your support, but I still didn't resolve my problem( – Oleg May 17 '17 at 18:38
I don't understand what you trying to achieve. Are you want to pass the `input1.getText().toString())` from activity to fragment, than set the value to all TextView ? And what is setTime about ? – John Joe May 18 '17 at 02:06
Also what is `pageNumber` ? – John Joe May 18 '17 at 02:07
Need to initialize variables which are in fragment.xml from my activity. – Oleg May 18 '17 at 11:02

Attempt to invoke virtual method on a null object reference

1 Answers1