Android: Can't Update Textview In Fragment From Activity. Nullpointerexception

I'm trying to update textview in fragment from another activity. But I'm getting a NUllPointerException when calling the setText method. I have tried the following, but still getti

Solution 1:

Use below callback:

Fragment Class:

publicclassFragmentOneextendsFragment {


private ViewCallback mCallback;

 publicFragmentOne(ViewCallback mCallback) {
    this.mCallback = mCallback;
}

@Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    view = inflater.inflate(R.layout.fragment_one, container, false);
    mCallback.updateTextView((TextView) view.findViewById(R.id.fragmentTextView));
    return view;
}

publicinterfaceViewCallback {
    voidupdateTextView(TextView view);
}
}

Below is the Activity class:

publicclassMainCallbackActivityextendsActivityimplementsCallbackFragment.ViewCallback {

publicTextView textView;

@OverrideprotectedvoidonCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_callback);

    FragmentOne fragment = newFragmentOne(this);
    getFragmentManager().beginTransaction().add(R.id.frameLayout, fragment).commit();

}

@OverrideprotectedvoidonResume() {
    super.onResume();
    if (textView != null)
        textView.setText("Updating Fragment TextView in Activity..!!");
}

@OverridepublicvoidupdateTextView(TextView view) {
    this.textView = view;
}
}

Implment that call back in your activity class..then update the textview.