我的应用程序出现问题.. 使用 XML 文件我正在获取地理点来绘制两个位置之间的路径..但​​它只显示距离小于 300 公里的路线.. 否则它不会绘制完整路径..

将 xml 文件分成 block 的任何解决方案..或任何替代方案..因为它给出的方向即使对于长距离也是完美的...那么问题是什么？我无法理解..

请帮忙..

编辑: 我发现 KML 文件有问题。 如果距离很长，它会提供两行字符串标签，每个字符串标签都有完整路径的坐标列表，分为多个部分。如下

<GeometryCollection>
<LineString>
<coordinates> 70.799640,22.283370,... </coordinates> </LineString>
<LineString>
<coordinates> 73.005940,21.536300,.... </coordinates> </LineString>
</GeometryCollection>

这就是为什么它将仅在字符串的后半部分的 map 上绘制路线。 所以..任何人都知道如何解决这个问题..

已编辑:-

public class DrivingDirectionsGoogleKML extends DrivingDirections
{
    @Override
    protected void startDrivingTo (GeoPoint startPoint, GeoPoint endPoint, Mode mode, IDirectionsListener listener)
    {
        new LoadDirectionsTask(startPoint, endPoint).execute(mode);
    }

    private class LoadDirectionsTask extends AsyncTask<Mode, Void, RouteImpl>
    {
        private static final String BASE_URL = "http://maps.google.com/maps?f=d&hl=en";
        private static final String ELEMENT_PLACEMARK = "Placemark";
        private static final String ELEMENT_NAME = "name";
        private static final String ELEMENT_DESC = "description";
        private static final String ELEMENT_POINT = "Point";
        private static final String ELEMENT_ROUTE = "Route";
        private static final String ELEMENT_GEOM = "GeometryCollection";

        private GeoPoint startPoint;
        private GeoPoint endPoint;

        public LoadDirectionsTask (GeoPoint startPoint, GeoPoint endPoint)
        {
            this.startPoint = startPoint;
            this.endPoint = endPoint;
        }

        @Override
        protected void onPreExecute() 
        {
            super.onPreExecute();
        }

        @Override
        protected RouteImpl doInBackground(Mode... params)
        {
            // Connect to the Google Maps web service that will return a KML string
            // containing the directions from one point to another.
            //
            StringBuilder urlString = new StringBuilder();
            urlString
                .append(BASE_URL)
                .append("&saddr=")
                .append(startPoint.getLatitudeE6() / 1E6)
                .append(",")
                .append(startPoint.getLongitudeE6() / 1E6)
                .append("&daddr=")
                .append(endPoint.getLatitudeE6() / 1E6)
                .append(",")
                .append(endPoint.getLongitudeE6() / 1E6)
                .append("&ie=UTF8&0&om=0&output=kml");

            if (params[0] == Mode.WALKING) 
            {
                urlString.append("&dirflg=w");
            }

            RouteImpl route = null;
            try 
            {
                URL url = new URL (urlString.toString());

                Log.i("-------- Url",url.toString());

                HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                connection.setRequestMethod("GET");
                connection.setDoOutput(true);
                connection.setDoInput(true);
                connection.connect();

                route = parseResponse (connection.getInputStream()); 
            }
            catch (Exception e) 
            {
                route = null;
            }

            return route;
        }

        private RouteImpl parseResponse(InputStream inputStream) throws Exception
        {
            // Parse the KML file returned by the Google Maps web service
            // using the default XML DOM parser.
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = factory.newDocumentBuilder();
            Document document = builder.parse(inputStream);         
            NodeList placemarkList = document.getElementsByTagName(ELEMENT_PLACEMARK);

            // Get the list of placemarks to plot along the route.
            List<Placemark> placemarks = new ArrayList<Placemark>();
            for (int i = 0; i < placemarkList.getLength(); i++)
            {
                PlacemarkImpl placemark = parsePlacemark (placemarkList.item(i));
                if (placemark != null) {
                    placemarks.add(placemark);
                }
            }

            // Get the route defining the driving directions.
            RouteImpl route = parseRoute (placemarkList);
            route.setPlacemarks(placemarks);
            return route;
        }

        private PlacemarkImpl parsePlacemark(Node item)
        {
            PlacemarkImpl placemark = new PlacemarkImpl ();

            boolean isRouteElement = false;
            NodeList children = item.getChildNodes();
            for (int i = 0; i < children.getLength(); i++)
            {
                Node node = children.item(i);
                if (node.getNodeName().equals(ELEMENT_NAME)) 
                {
                    String name = node.getFirstChild().getNodeValue();
                    if (name.equals(ELEMENT_ROUTE)) 
                    {
                        isRouteElement = true;
                    }
                    else 
                    {
                        isRouteElement = false;
                        placemark.setInstructions(name);
                    }
                }
                else if (node.getNodeName().equals(ELEMENT_DESC)) 
                {
                    if (!isRouteElement) 
                    {
                        String distance = node.getFirstChild().getNodeValue();
                        placemark.setDistance(distance.substring(3).replace("&#160;", " "));
                    }
                }
                else if (node.getNodeName().equals(ELEMENT_POINT)) 
                {
                    if (!isRouteElement) 
                    {
                        String coords = node.getFirstChild().getFirstChild().getNodeValue();
                        String[] latlon = coords.split(",");
                        placemark.setLocation(new GeoPoint ((int) (Double.parseDouble(latlon[1]) * 1E6),(int) (Double.parseDouble(latlon[0]) * 1E6)));
                    }
                }
            }
            return isRouteElement ? null : placemark;
        }

        private RouteImpl parseRoute(NodeList placemarkList)
        {
            RouteImpl route = null;

            for (int i = 0; i < placemarkList.getLength(); i++)
            {
                // Iterate through all the <Placemark> KML tags to find the one
                // whose child <name> tag is "Route".
                //
                Node item = placemarkList.item(i);
                NodeList children = item.getChildNodes();
                for (int j = 0; j < children.getLength(); j++)
                {
                    Node node = children.item(j);
                    if (node.getNodeName().equals(ELEMENT_NAME))
                    {
                        String name = node.getFirstChild().getNodeValue();
                        if (name.equals(ELEMENT_ROUTE))
                        {
                            route = parseRoute (item);
                            break;
                        }
                    }
                }
            }
            return route;
        }

        private RouteImpl parseRoute(Node item)
        {
            RouteImpl route = new RouteImpl ();

            NodeList children = item.getChildNodes();
            for (int i = 0; i < children.getLength(); i++)
            {
                Node node = children.item(i);

                if (node.getNodeName().equals(ELEMENT_DESC)) 
                {
                    // Get the value of the <description> KML tag.
                    String distance = node.getFirstChild().getNodeValue();
                    route.setTotalDistance(distance.split("<br/>")[0].substring(10).replace("&#160;", " "));
                }
                else if (node.getNodeName().equals(ELEMENT_GEOM)) //Here Reading Co-Ordinates..///
                {

                    String path = node.getFirstChild().getFirstChild().getFirstChild().getNodeValue();
                    String[] pairs = path.split(" ");

                    // For each coordinate, get its {latitude, longitude} values and add the corresponding geographical point to the route.

                    List<GeoPoint> geoPoints = new ArrayList<GeoPoint>();
                    for (int p = 0; p < pairs.length; p++) 
                    {
                        String[] coords = pairs[p].split(",");
                        GeoPoint geoPoint = new GeoPoint ((int) (Double.parseDouble(coords[1]) * 1E6),(int) (Double.parseDouble(coords[0]) * 1E6));
                        geoPoints.add (geoPoint);
                    }
                    route.setGeoPoints(geoPoints);

                }
            }

            return route;
        }

        protected void onPostExecute (RouteImpl route)
        {
            if (route == null) 
            {
                DrivingDirectionsGoogleKML.this.onDirectionsNotAvailable();
            }
            else 
            {
                DrivingDirectionsGoogleKML.this.onDirectionsAvailable(route); 
            }
        }
    }
}

最佳答案

我已经找到解决方案了.. 创建的节点列表 <GeometryCollection>....</GeometryCollection> 它将提供两个位置之间的所有坐标..

private RouteImpl parseRoute(Node item)
        {
            RouteImpl route = new RouteImpl ();
            NodeList children = item.getChildNodes();
            for (int i = 0; i < children.getLength(); i++)
            {
                Node node = children.item(i);

                if (node.getNodeName().equals(ELEMENT_DESC)) 
                {
                    // Get the value of the <description> KML tag.
                    //
                    String distance = node.getFirstChild().getNodeValue();
                    route.setTotalDistance(distance.split("<br/>")[0].substring(10).replace("&#160;", " "));
                }
                else if (node.getNodeName().equals(ELEMENT_GEOM)) 
                {
                    // Get the space-separated coordinates of the geographical points defining the route.
                    //

                    List<GeoPoint> geoPoints = new ArrayList<GeoPoint>();

                                    // Create a NodeList  here ..
                    NodeList geoMetryChildren = node.getChildNodes();

                    for(int k=0;k<geoMetryChildren.getLength();k++)
                    {
                        Node geoMetryChildrenNode = geoMetryChildren.item(k);
                        String path = geoMetryChildrenNode.getFirstChild().getFirstChild().getNodeValue();

                        String[] pairs = path.split(" ");

                        for (int p = 0; p < pairs.length; p++) 
                        {
                            String[] coords = pairs[p].split(",");
                            GeoPoint geoPoint = new GeoPoint ((int) (Double.parseDouble(coords[1]) * 1E6),(int) (Double.parseDouble(coords[0]) * 1E6));
                            geoPoints.add (geoPoint);
                        }
                    }
                    route.setGeoPoints(geoPoints);
                }
            }

            return route;
        }

关于使用 XML 解析在 MapView 上绘制长路径的 Android 问题，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/5298418/