The canvas needs something to draw onto. However, in your case you might be better served adding your code to the draw method in HelloItemizedOverlay. That method has a canvas passed to it which will already by correctly set up.
On Jun 21, 2:05 am, mnish <[email protected]> wrote: > Hello, > I have a problem with drawing lines between two points on google map. > I get nullpointerexception on this line of code: > canvas.drawLine(p1.x, p1.y, p2.x, p2.y, paint); > > I know this is a very basic thing, but I don't know not much about it > and I really really need your help. > > here is were i call this method: > > @Override > public void onCreate(Bundle savedInstanceState) { > super.onCreate(savedInstanceState); > setContentView(R.layout.main); > > linearLayout = (LinearLayout) findViewById > (R.id.zoomview); > mapView = (MapView) findViewById(R.id.mapview); > mapView.setBuiltInZoomControls(on); > mapOverlays = mapView.getOverlays(); > drawable = this.getResources().getDrawable > (R.drawable.circle); > itemizedoverlay = new HelloItemizedOverlay(drawable); > Projection projection = mapView.getProjection(); > > Double lat1 = 30.342833*1E6, lon1 = -91.719033*1E6; > Double lat2 = -37.5262180*1E6, lon2 = 175.8060710*1E6; > point1 = new GeoPoint(lat1.intValue(), lon1.intValue > ()); > point2 = new GeoPoint(lat2.intValue(), lon2.intValue > ()); > p1 = new Point(); > p2 = new Point(); > projection.toPixels(point1, p1); > projection.toPixels(point2, p2); > canvas = new Canvas(); > canvas.drawLine(p1.x, p1.y, p2.x, p2.y, paint); > > }. > > Please tell me what do i do wrong. > Any help is more than welcome --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Android Beginners" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en -~----------~----~----~----~------~----~------~--~---
