Question

I am creating an app which has action bar and 2 tabs. like this:

Tab1: on click should display some details of a place.
Tab2: on click should display maps.

I am using Fragments for this.

My tablistener:

private class MyTabListener implements ActionBar.TabListener {
        @Override
        public void onTabSelected(Tab tab,
                android.support.v4.app.FragmentTransaction ft) {
            // TODO Auto-generated method stub
            if (tab.getPosition() == 0) {
                DetailsFragment fragment = new DetailsFragment();
                ft.replace(android.R.id.content, fragment);

            } else {
                MapsFragment fragment = new MapsFragment();
                ft.replace(android.R.id.content, fragment);
                //ft.commit();
            }
        }

MapsFragment.java

public class MapsFragment extends MapFragment {

    private MapView map = null;
    private MyLocationOverlay me = null;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        return (new FrameLayout(getActivity()));
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        map = new MapView(getActivity(),
                "0rQAS47Cicu2t7z4w8Ev6A6de7QlbjvKyi8I-QQ");
        map.setClickable(true);

        map.getController().setCenter(
                getPoint(40.76793169992044, -73.98180484771729));
        map.getController().setZoom(17);
        map.setBuiltInZoomControls(true);

        Drawable marker = getResources().getDrawable(R.drawable.marker);

        marker.setBounds(0, 0, marker.getIntrinsicWidth(),
                marker.getIntrinsicHeight());

        map.getOverlays().add(new SitesOverlay(marker));

        me = new MyLocationOverlay(getActivity(), map);
        map.getOverlays().add(me);

        ((ViewGroup) getView()).addView(map);
    }

    @Override
    public void onResume() {
        super.onResume();

        me.enableCompass();
    }

    @Override
    public void onPause() {
        super.onPause();

        me.disableCompass();
    }

    private GeoPoint getPoint(double lat, double lon) {
        return (new GeoPoint((int) (lat * 1000000.0), (int) (lon * 1000000.0)));
    }

    private class SitesOverlay extends ItemizedOverlay<OverlayItem> {
        private List<OverlayItem> items = new ArrayList<OverlayItem>();

        public SitesOverlay(Drawable marker) {
            super(marker);

            boundCenterBottom(marker);

            items.add(new OverlayItem(getPoint(40.748963847316034,
                    -73.96807193756104), "UN", "United Nations"));
            items.add(new OverlayItem(getPoint(40.76866299974387,
                    -73.98268461227417), "Lincoln Center",
                    "Home of Jazz at Lincoln Center"));
            items.add(new OverlayItem(getPoint(40.765136435316755,
                    -73.97989511489868), "Carnegie Hall",
                    "Where you go with practice, practice, practice"));
            items.add(new OverlayItem(getPoint(40.70686417491799,
                    -74.01572942733765), "The Downtown Club",
                    "Original home of the Heisman Trophy"));

            populate();
        }

        @Override
        protected OverlayItem createItem(int i) {
            return (items.get(i));
        }

        @Override
        protected boolean onTap(int i) {
            Toast.makeText(getActivity(), items.get(i).getSnippet(),
                    Toast.LENGTH_SHORT).show();

            return (true);
        }

        @Override
        public int size() {
            return (items.size());
        }
    }
}

The problem is when i click on maps tab for the first time map appears. but wen i go to details tab and again come back to maps tab, my app crashes with an error:

Logcat:

12-04 03:28:02.228: E/AndroidRuntime(14466): FATAL EXCEPTION: main
12-04 03:28:02.228: E/AndroidRuntime(14466): java.lang.IllegalStateException: You are only allowed to have a single MapView in a MapActivity
12-04 03:28:02.228: E/AndroidRuntime(14466):    at com.google.android.maps.MapActivity.setupMapView(MapActivity.java:398)
12-04 03:28:02.228: E/AndroidRuntime(14466):    at com.google.android.maps.MapView.<init>(MapView.java:289)
12-04 03:28:02.228: E/AndroidRuntime(14466):    at com.google.android.maps.MapView.<init>(MapView.java:235)
12-04 03:28:02.228: E/AndroidRuntime(14466):    at com.m7.nomad.MapsFragment.onCreate(MapsFragment.java:34)
12-04 03:28:02.228: E/AndroidRuntime(14466):    at android.support.v4.app.FragmentManagerImpl.moveToState(Unknown Source)
12-04 03:28:02.228: E/AndroidRuntime(14466):    at android.support.v4.app.FragmentManagerImpl.moveToState(Unknown Source)
12-04 03:28:02.228: E/AndroidRuntime(14466):    at android.support.v4.app.BackStackRecord.run(Unknown Source)
12-04 03:28:02.228: E/AndroidRuntime(14466):    at android.support.v4.app.FragmentManagerImpl.execPendingActions(Unknown Source)
12-04 03:28:02.228: E/AndroidRuntime(14466):    at android.support.v4.app.FragmentManagerImpl$1.run(Unknown Source)
12-04 03:28:02.228: E/AndroidRuntime(14466):    at android.os.Handler.handleCallback(Handler.java:725)
12-04 03:28:02.228: E/AndroidRuntime(14466):    at android.os.Handler.dispatchMessage(Handler.java:92)
12-04 03:28:02.228: E/AndroidRuntime(14466):    at android.os.Looper.loop(Looper.java:137)
12-04 03:28:02.228: E/AndroidRuntime(14466):    at android.app.ActivityThread.main(ActivityThread.java:5039)
12-04 03:28:02.228: E/AndroidRuntime(14466):    at java.lang.reflect.Method.invokeNative(Native Method)
12-04 03:28:02.228: E/AndroidRuntime(14466):    at java.lang.reflect.Method.invoke(Method.java:511)
12-04 03:28:02.228: E/AndroidRuntime(14466):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
12-04 03:28:02.228: E/AndroidRuntime(14466):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
12-04 03:28:02.228: E/AndroidRuntime(14466):    at dalvik.system.NativeStart.main(Native Method)

What is the problem. I know that MapView cant be inflated from fragment. But i used this technique:
http://xrigau.wordpress.com/2012/03/22/howto-actionbarsherlock-mapfragment-listfragment/

But still this doesn’t work. I need some Help.

Answer 1

Just some days ago Google has introduced Map Api 2. And it containts MapFragment. So now you don’t need such hooks.
https://developers.google.com/maps/documentation/android/reference/com/google/android/gms/maps/MapFragment