Create mapView programmatically

Question

I want to instantiate a MapView programmatically. I'm using Osmdroid. I wrote this, but map is not displayed (with or without setting the parameters)! What's wrong?

    LinearLayout contentLayout = (LinearLayout) findViewById(R.id.contentLayout);

    m_mapView = new MapView(this, 10);

    org.osmdroid.views.MapView.LayoutParams mapParams = new org.osmdroid.views.MapView.LayoutParams(
            org.osmdroid.views.MapView.LayoutParams.MATCH_PARENT,
            org.osmdroid.views.MapView.LayoutParams.MATCH_PARENT,
            null, 0, 0, 0);

    m_mapView.setBuiltInZoomControls(true);

    m_mapView.setMultiTouchControls(false);     

    mapController = this.m_mapView.getController();
    mapController.setZoom(MAP_DEFAULT_ZOOM);
    m_mapView.getController().setCenter( new GeoPoint(MAP_DEFAULT_LATITUDE, MAP_DEFAULT_LONGITUDE));

    m_mapView.invalidate();

    contentLayout.addView(m_mapView,mapParams);

Answer 1

I really want to help you because your post helped me with my problem displaying an osmdroid map programmatically: I was adding the map view to a linear layout as you did, but was not including the layout parameters as you did, and the map was coming up blank. Thank you!

I think your problem is that you did not specify a tile source. Here's the code I used, and it successfully drew the map. It's identical to yours except for adding a tile source, replacing your constants with values, and for changing your variable name mapController to m_mapController, which I assume was defined the same was as your mapView. I just didn't want anyone to think it was defined within the method and not shown.

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    LinearLayout contentLayout = (LinearLayout) findViewById(R.id.contentLayout);
    m_mapView = new MapView(this, 10);
    m_mapView.setTileSource(TileSourceFactory.MAPNIK);
    org.osmdroid.views.MapView.LayoutParams mapParams = new org.osmdroid.views.MapView.LayoutParams(
            org.osmdroid.views.MapView.LayoutParams.MATCH_PARENT,
            org.osmdroid.views.MapView.LayoutParams.MATCH_PARENT,
            null, 0, 0, 0);
    m_mapView.setBuiltInZoomControls(true);
    m_mapView.setMultiTouchControls(false);     
    m_mapController = this.m_mapView.getController();
    m_mapController.setZoom(15);
    m_mapView.getController().setCenter( new GeoPoint(51496994, -134733));
    m_mapView.invalidate();
    contentLayout.addView(m_mapView, mapParams);
}

I used this helpful page when I started with osmdroid, and it makes a good sanity check when I'm off in the weeds with my own modifications.

I hope this helps... thanks again for the hint you provided me with!