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如何在谷歌地图上找到两点之间的最佳路线并将其突出显示？

androidgoogle-mapsgps
4
假设我在谷歌地图上有两个地理位置（点），现在我想通过不同的城市突出这两个点之间的最佳路线。我该怎么做？我在互联网上搜索并发现在谷歌地图上绘制直线/路径，但这只解释了如何在两个点之间画一条直线。我需要找到连接不同城市和至少穿过两个点之间的地方的路线，而不是一条直线。有人能给我一些好的教程或一些思路吗？
回答：如果其他人也遇到这个问题，请查看被采纳的答案。要实施最佳路线，请参考http://csie-tw.blogspot.com/2009/06/android-driving-direction-route-path.html。这是一个带有工作代码的优秀教程。您可以根据需要进行修改。还有一件事，在测试时，请只提供可能存在路径的坐标（这是我的错误）。其余都没问题。请使用这些代码。谢谢。
你是想使用Google Maps API来计算路线，还是尝试自己通过网络定义来实现？ - ViennaMike
2个回答
1

仔细阅读这些代码。根据你的需求修改代码。

//mapdirection.java
public class mapdirection extends MapActivity{

MapView mapview;
MapRouteOverlay mapoverlay;
Context _context;
List<Overlay> maplistoverlay;
Drawable drawable,drawable2;
MapOverlay mapoverlay2,mapoverlay3;
GeoPoint srcpoint,destpoint;
Overlay overlayitem;
public void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);  
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
    setContentView(R.layout.map_direction);
    RegisterActivities.registerActivity(this);
    mapview=(MapView)this.findViewById(R.id.mapview);

    callMap();
}
private void callMap() {
      srcpoint=new GeoPoint((int)(Data.src_lat_date*1E6),(int)(Data.src_long_data*1E6));
      maplistoverlay=mapview.getOverlays();
      drawable=this.getResources().getDrawable(R.drawable.green_a);
      mapoverlay2=new MapOverlay(drawable);
      OverlayItem overlayitem = new OverlayItem(srcpoint, "", "");
      mapoverlay2.addOverlay(overlayitem);
      maplistoverlay.add(mapoverlay2);

      destpoint=new GeoPoint((int)(Data.dest_lat_data*1E6),(int)(Data.dest_long_data*1E6));
      drawable2=this.getResources().getDrawable(R.drawable.green_b);
      mapoverlay3=new MapOverlay(drawable2);
      OverlayItem overlayitem3 = new OverlayItem(destpoint, "", "");
      mapoverlay3.addOverlay(overlayitem3);
      maplistoverlay.add(mapoverlay3);


  double dest_lat = Data.dest_lat_data;
  double dest_long = Data.dest_long_data;

  GeoPoint srcGeoPoint = new GeoPoint((int) (Data.src_lat_date* 1E6),
  (int) (Data.src_long_data * 1E6));
  GeoPoint destGeoPoint = new GeoPoint((int) (dest_lat * 1E6),
  (int) (dest_long * 1E6));

  DrawPath(srcGeoPoint, destGeoPoint, Color.BLUE, mapview);

  mapview.getController().animateTo(srcGeoPoint);
  mapview.getController().setZoom(13);
  //mapview.setStreetView(true);
  mapview.setBuiltInZoomControls(true);
  mapview.invalidate();


}
private void DrawPath(GeoPoint src, GeoPoint dest, int color,
        MapView mMapView01) {

    // connect to map web service
    StringBuilder urlString = new StringBuilder();
    urlString.append("http://maps.google.com/maps?f=d&hl=en");
    urlString.append("&saddr=");//from
    urlString.append( Double.toString((double)src.getLatitudeE6()/1.0E6 ));
    urlString.append(",");
    urlString.append( Double.toString((double)src.getLongitudeE6()/1.0E6 ));
    urlString.append("&daddr=");//to
    urlString.append( Double.toString((double)dest.getLatitudeE6()/1.0E6 ));
    urlString.append(",");
    urlString.append( Double.toString((double)dest.getLongitudeE6()/1.0E6 ));
    urlString.append("&ie=UTF8&0&om=0&output=kml");
    Log.d("xxx","URL="+urlString.toString());

    //System.out.println(urlString);
    // get the kml (XML) doc. And parse it to get the coordinates(direction route).
    Document doc = null;
    HttpURLConnection urlConnection= null;
    URL url = null;
    try
    {
    url = new URL(urlString.toString());
    urlConnection=(HttpURLConnection)url.openConnection();
    urlConnection.setRequestMethod("GET");
    urlConnection.setDoOutput(true);
    urlConnection.setDoInput(true);
    urlConnection.connect();

    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    DocumentBuilder db = dbf.newDocumentBuilder();
    doc = db.parse(urlConnection.getInputStream());

    if(doc.getElementsByTagName("GeometryCollection").getLength()>0)
    {
    //String path = doc.getElementsByTagName("GeometryCollection").item(0).getFirstChild().getFirstChild().getNodeName();
    String path = doc.getElementsByTagName("GeometryCollection").item(0).getFirstChild().getFirstChild().getFirstChild().getNodeValue() ;
    Log.d("xxx","path="+ path);
    String [] pairs = path.split(" ");
    String[] lngLat = pairs[0].split(","); // lngLat[0]=longitude lngLat[1]=latitude lngLat[2]=height
    // src
    GeoPoint startGP = new GeoPoint((int)(Double.parseDouble(lngLat[1])*1E6),(int)(Double.parseDouble(lngLat[0])*1E6));
    //mMapView01.getOverlays().add(overlayitem);
    GeoPoint gp1;
    GeoPoint gp2 = startGP;
    for(int i=1;i<pairs.length;i++) // the last one would be crash
    {
    lngLat = pairs[i].split(",");
    gp1 = gp2;
    // watch out! For GeoPoint, first:latitude, second:longitude
    gp2 = new GeoPoint((int)(Double.parseDouble(lngLat[1])*1E6),(int)(Double.parseDouble(lngLat[0])*1E6));
    mMapView01.getOverlays().add(new MapRouteOverlay(gp1,gp2,2,color));
    Log.d("xxx","pair:" + pairs[i]);
    }
    //mMapView01.getOverlays().add(new MapRouteOverlay(dest,dest, 3)); // use the default color
    }
    }
    catch (MalformedURLException e)
    {
    e.printStackTrace();
    }
    catch (IOException e)
    {
    e.printStackTrace();
    }
    catch (ParserConfigurationException e)
    {
    e.printStackTrace();
    }
    catch (SAXException e)
    {
    e.printStackTrace();
    }       
}
@Override
protected boolean isRouteDisplayed() {
    // TODO Auto-generated method stub
    return false;
}
//MapRouteOverlay.java

public class MapRouteOverlay extends Overlay {

private GeoPoint gp1;
private GeoPoint gp2;

private int mode=0;
private int defaultColor;

public MapRouteOverlay(GeoPoint gp1,GeoPoint gp2,int mode) // GeoPoint is a int. (6E)
{
this.gp1 = gp1;
this.gp2 = gp2;
this.mode = mode;
defaultColor = 999; // no defaultColor

}

public MapRouteOverlay(GeoPoint gp1,GeoPoint gp2,int mode, int defaultColor)
{
this.gp1 = gp1;
this.gp2 = gp2;
this.mode = mode;
this.defaultColor = defaultColor;
}

public int getMode()
{
return mode;
}

public boolean draw
(Canvas canvas, MapView mapView, boolean shadow, long when)
{
Projection projection = mapView.getProjection();
if (shadow == false)
{

Paint paint = new Paint();
paint.setAntiAlias(true);
Point point = new Point();
projection.toPixels(gp1, point);

if(mode==2)
{
if(defaultColor==999)
paint.setColor(Color.RED);
else
paint.setColor(defaultColor);
Point point2 = new Point();
projection.toPixels(gp2, point2);
paint.setStrokeWidth(5);
paint.setAlpha(120);
canvas.drawLine(point.x, point.y, point2.x,point2.y, paint);
}
}
return super.draw(canvas, mapView, shadow, when);
}
}
很抱歉要说，但它仍然无法工作。这次我尝试了有效的输入，如“27.11 78.11”和“25.00 81.45”。你能帮我看看哪里出了问题吗？我一定会为你的答案投票并接受它，但请帮帮我。我真的被卡住了。 - dark_shadow
请发送你的新的日志输出。 - Waza_Be
这是我的新logcat输出，但不知何故我觉得问题在于它无法从互联网下载KML文件，但请看看是否有我漏掉的东西。http://pastebin.com/YE2eMYk4 - dark_shadow
你在应用清单中添加了网络权限吗？ - Waza_Be
你的 pastebin 链接中，kml 文件地址在第 166 行，这个可以正常工作！我不理解。 - Waza_Be
显示剩余7条评论
1

是的，我知道回答这个问题有些晚了。但我认为这可以帮助其他人。

将此代码放在onCreate中或自己的方法中。

    MapView mv = (MapView)findViewById(R.id.mvGoogle);
    mv.setBuiltInZoomControls(true);
    MapController mc = mv.getController();
    //getDirections(lat1,lon2,lat2,lon2);
    ArrayList<GeoPoint> all_geo_points = getDirections(10.154929, 76.390316, 10.015861, 76.341867);
    if(all_geo_points.size()>0){
    GeoPoint moveTo = all_geo_points.get(0);
    mc.animateTo(moveTo);
    mc.setZoom(12);
    mv.getOverlays().add(new MyOverlay(all_geo_points));
    }else {
        Toast.makeText(getApplicationContext(), "Not able to show route !!", Toast.LENGTH_LONG).show();
    }

现在创建你自己的自定义覆盖层类。
    public class MyOverlay extends Overlay {
    private ArrayList<GeoPoint> all_geo_points;

    public MyOverlay(ArrayList<GeoPoint> allGeoPoints) {
        super();
        this.all_geo_points = 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.FILL_AND_STROKE);
        paint.setStrokeWidth(4);
        paint.setAlpha(100);
        if (all_geo_points != null) for (int i = 0; i < all_geo_points.size() - 4; i++) {
            GeoPoint gp = all_geo_points.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;
        }
    }
}

现在这个方法将会给你所有的 GeoPoints 以便画出路线。我建议把这段代码放在单独的 AsyncTask 中。
public static ArrayList<GeoPoint> 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<GeoPoint> list_of_geopoints = new ArrayList<GeoPoint>();
    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);
        if (doc != null) {
            NodeList nl1, nl2;
            nl1 = doc.getElementsByTagName(tag[0]);
            nl2 = doc.getElementsByTagName(tag[1]);
            if (nl1.getLength() > 0) {
                list_of_geopoints = new ArrayList<GeoPoint>();
                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());
                    list_of_geopoints.add(new GeoPoint((int) (lat * 1E6), (int) (lng * 1E6)));
                }
            } else {
                // No points found
            }
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
    return list_of_geopoints;
}
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