I have initialized paint now. The nullpointerexception is solved by this. But i still can't see any line on the map. As you said I have to attach the canvas to the view or so. I have read the links you supplied. But I dont understand it. I need to use the MapView and draw lines on it. How can i do this. Could you please show me in a simple way how i can do this?
thank you On Jun 21, 4:55 am, Marco Nelissen <marc...@android.com> wrote: > The problem is those last two lines: canvas = new Canvas(); > canvas.drawLine(p1.x, p1.y, p2.x, p2.y, paint); > > That creates a new Canvas, then draws in to it. The problem with that is > that the Canvas isn't "attached" to anything, so you're essentially drawing > in to something that is not visible. > You should probably have a look > at:http://developer.android.com/reference/android/view/View.html#onDraw(...) > > On Sat, Jun 20, 2009 at 7:14 PM, nEx.Software > <justin.shapc...@gmail.com>wrote: > > > > > In your code, I am not seeing anywhere that you have initialized > > paint. That would be the first place I'd look. > > > On Jun 20, 5:50 pm, mnish <twan...@gmail.com> 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); > > > > } > > > > Any help is more than welcome. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -~----------~----~----~----~------~----~------~--~---
