Launching FragmentActivity From Fragment

Question

I'm having problems getting the below code to Work. When I hit the Image button it crashes the app. Can some one please point to where I am going wrong with the below code?

public class training extends Fragment {
        ImageButton run;
        public training()
        {
        }

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


            return rootView;
        }
        @Override
        public void onActivityCreated(Bundle savedInstanceState) {
            super.onActivityCreated(savedInstanceState);
            run = (ImageButton) getActivity().findViewById
                    (R.id.StartRunClass);
            run.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Intent i= new Intent(getActivity(),Running.class);
                    getActivity().startActivity(i);
                }
            });


        }
    }

All I have in the Class Being Called is

public class Running extends FragmentActivity
        //implements LocationProvider.LocationCallback {
   // private GoogleMap mMap; // Might be null if Google Play services APK is not available.
    //public LocationProvider mLocationProvider;
{
    ImageButton start, stop;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.fragment_run);

Getting the Following Run Time Errors

02-24 16:12:26.377  30732-30732/project.project E/AndroidRuntime﹕ FATAL EXCEPTION: main
    java.lang.NullPointerException
            at project.project.training.run(training.java:38)
            at project.project.training.onCreateView(training.java:30)
            at android.app.Fragment.performCreateView(Fragment.java:1695)
            at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:885)
            at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1057)
            at android.app.BackStackRecord.run(BackStackRecord.java:694)
            at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1435)
            at android.app.FragmentManagerImpl$1.run(FragmentManager.java:441)
            at android.os.Handler.handleCallback(Handler.java:800)
            at android.os.Handler.dispatchMessage(Handler.java:100)
            at android.os.Looper.loop(Looper.java:194)
            at android.app.ActivityThread.main(ActivityThread.java:5392)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:525)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
            at dalvik.system.NativeStart.main(Native Method)

Answer 1

I'm pretty sure the problem is with getActivity() returning null .

Override OnAttach and store a reference to attached activity:

Activity activity;

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

Replace getActivity() by your reference:

@Override
public void onClick(View v) {
    Intent i= new Intent(activity,Running.class);
    activity.startActivity(i);
}

---

EDIT

It crashes because run is null. I think the problem is with the way you use findViewByID :

run = (ImageButton) getActivity().findViewById(R.id.StartRunClass);

You should do that at onCreateView and using rootView instead of getActivity :

View rootView = inflater.inflate(R.layout.fragment_training, container, false);
run = (ImageButton) rootView.findViewById(R.id.StartRunClass);

If it still crashes, check fragment_training layout to be sure that it contains an ImageView called StartRunClass .