Question

我是Android新手。我想在我的应用程序中从一个位置绘制一条线到另一个位置。如何在Android中的两点之间画一条线？请帮帮我。

Answer 1

您应该向地图添加Overlay并覆盖它的onDraw()方法。这样你就可以在地图上绘制任何你想要的东西。

Answer 2

使用它对我来说很好用

mapView.setBuiltInZoomControls(true);
            mapController = mapView.getController();
            ArrayList allGeoPoints = getDirections(8.487495, 76.948623,toLat 10.015861, 76.341867toLon);
            GeoPoint moveTo =  new GeoPoint(startLattitude, startLongigude);
            mapController.setCenter(moveTo);
            //mc.animateTo(moveTo);
            mapController.setZoom(12);
            mapView.getOverlays().add(new MyOverlay(allGeoPoints));


public static ArrayList getDirections(double lat1, double lon1, double lat2, double lon2) {
        String url = "http://maps.googleapis.com/maps/api/directions/xml?origin=" +lat1 + "," + lon1  + "&destination=" + lat2 + "," + lon2 + "&sensor=false&units=metric";
        String tag[] = { "lat", "lng" };
        ArrayList listOfGeopoints = new ArrayList();
        HttpResponse response = null;
        try {
            HttpClient httpClient = new DefaultHttpClient();
            HttpContext localContext = new BasicHttpContext();
            HttpPost httpPost = new HttpPost(url);
            response = httpClient.execute(httpPost, localContext);
            InputStream in = response.getEntity().getContent();
            DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
            Document doc = builder.parse(in);
            Log.e("**********************   ",new JsonOperations().convertStreamToString(in).toString());
            if (doc != null) {
                NodeList nl1, nl2;
                nl1 = doc.getElementsByTagName(tag[0]);
                nl2 = doc.getElementsByTagName(tag[1]);
                if (nl1.getLength() > 0) {
                    listOfGeopoints = new ArrayList();
                    for (int i = 0; i < nl1.getLength(); i++) {
                        Node node1 = nl1.item(i);
                        Node node2 = nl2.item(i);
                        double lat = Double.parseDouble(node1.getTextContent());
                        double lng = Double.parseDouble(node2.getTextContent());
                        listOfGeopoints.add(new GeoPoint((int) (lat * 1E6), (int) (lng * 1E6)));
                    }
                } else {
                    // No points found
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return listOfGeopoints;
    }

和myoverlay类

public class MyOverlay extends Overlay {

    private ArrayList allGeoPoints;

    public MyOverlay(ArrayList allGeoPoints) {
        super();
        this.allGeoPoints = allGeoPoints;
    }

    @Override
    public boolean draw(Canvas canvas, MapView mv, boolean shadow, long when) {
        super.draw(canvas, mv, shadow);
        drawPath(mv, canvas);
        return true;
    }

    public void drawPath(MapView mv, Canvas canvas) {
        int xPrev = -1, yPrev = -1, xNow = -1, yNow = -1;
        Paint paint = new Paint();
        paint.setColor(Color.BLUE);
        paint.setStyle(Paint.Style.STROKE);
        paint.setStrokeWidth(4);
        //paint.setAlpha(100);
        if (allGeoPoints != null)
            for (int i = 0; i < allGeoPoints.size() - 4; i++) {
                GeoPoint gp = (GeoPoint) allGeoPoints.get(i);
                Point point = new Point();
                mv.getProjection().toPixels(gp, point);
                xNow = point.x;
                yNow = point.y;
                if (xPrev != -1) {
                    canvas.drawLine(xPrev, yPrev, xNow, yNow, paint);
                }
                xPrev = xNow;
                yPrev = yNow;
            }
    }
}

如何在Android中的Google地图中的两点之间画一条线？

2 个答案: