Question

I cannot seem to find out what this error means. Can you all help me out?

Here is my source code in the MainView.java. After logging into the app, this is the first screen you see, it should show the header, then a google maps api, then the menu at the bottom.

public class MainView extends FragmentActivity implements OnClickListener {

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        return inflater.inflate(R.layout.main_view, container, false);
    }


    @Override
    protected void onStart() {
        // TODO Auto-generated method stub
        super.onStart();

        Fragment fragment;

        Button openDrawer = (Button) findViewById(R.id.openDrawer);
        openDrawer.setOnClickListener(this);

        Button openUploader = (Button) findViewById(R.id.menuButtonAdd);
        openUploader.setOnClickListener(this);
        Button openEditor = (Button) findViewById(R.id.menuButtonEdit);
        openEditor.setOnClickListener(this);
        Button openMap = (Button) findViewById(R.id.menuButtonMap);
        openMap.setOnClickListener(this);
        Button openPeople = (Button) findViewById(R.id.menuButtonPeople);
        openPeople.setOnClickListener(this);

        FragmentManager fm = getSupportFragmentManager();
        FragmentTransaction ft = fm.beginTransaction();

        Map myFragment = new Map();
        ft.add(R.id.mainFragment, myFragment);
        ft.commit();
    }


    public void onClick(View arg0) {
        Fragment newFragment = new Map();

        switch (arg0.getId()) {
        case(R.id.openDrawer):
            SlidingDrawer menuDrawer = (SlidingDrawer) findViewById(R.id.menuDrawer);
            //SlidingDrawer textDrawer = (SlidingDrawer) findViewById(R.id.textDrawer);
            if (menuDrawer.isOpened() == true) {
                menuDrawer.animateClose();
                //textDrawer.animateClose();
            } else if (menuDrawer.isOpened() == false) {
                menuDrawer.animateOpen();
                //textDrawer.animateOpen();
            }
            break;
        case(R.id.menuButtonAdd):
            newFragment = new UploadFragment();
            break;
        case(R.id.menuButtonEdit):
            newFragment = new EditGallery();
            break;
        case(R.id.menuButtonMap):
            newFragment = new Map();
            break;
        case(R.id.menuButtonPeople):
            // TODO present an error
            break;
        default:
            newFragment = new Map();
            break;
        }

        FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
        transaction.replace(R.id.mainFragment, newFragment);
        transaction.commit();
    }
}

Code at line 37:

openDrawer.setOnClickListener(this);

Answer 1

It means you’ve got a NullPointerException on this line: com.fotolife.app.MainView.onStart(MainView.java:37)

This is because openDrawer is null, because it cannot be found in the view.

You need to add this:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main_view);
}

and remove the onCreateView method.