Android-谷歌地图V2：从当前位置跟踪路由到其它目的地 [英] Android- Google Maps V2 : Trace route from current position to an other destination
问题描述
我开始与本例中，画出2个地址，类型由用户之间的路由。这是工作。 <一href=\"http://blog.rolandl.fr/1357-android-des-itineraires-dans-vos-applications-grace-a-lapi-google-direction\" rel=\"nofollow\">http://blog.rolandl.fr/1357-android-des-itineraires-dans-vos-applications-grace-a-lapi-google-direction
I started with this example, to draw a route between 2 address, type by the user. It is working. http://blog.rolandl.fr/1357-android-des-itineraires-dans-vos-applications-grace-a-lapi-google-direction
但现在我想从我的当前位置画一个路线到其他目的地，类型用户。
我的问题是，不知道如何检索当前位置，在这种情况下。
我试图做的事：
But now I would like to draw a route from my current position to an other destination, type by the user. My problem is that I don't know how to retrieve the current position, in this case. I've tried to do :
LocationManager locationmanager=(LocationManager)this.getSystemService(LOCATION_SERVICE);
final double longitude=locationmanager.getLongitude();
final double latitude=locationmanager.getLatitude();
但它不会工作...我想我每次混合例如我发现，这是不好的。
But it will not work... I think I am mixing every example I've found, and it is not good at all.
您可以帮帮我吗？
下面是我的 MapActivity ：
接收由用户在我MainActivity键入2地址
公共类MapActivity扩展活动实现LocationListener的
{
私人GoogleMap的GoogleMap的;
Here is my MapActivity : Receiving 2 address typed by the user in my MainActivity public class MapActivity extends Activity implements LocationListener { private GoogleMap googlemap;
protected void onCreate(final Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_map);
// Recuperation des composants graphiques
googlemap = ((MapFragment)getFragmentManager().findFragmentById(R.id.map)).getMap();
//Recuperations des adresses depart-arrivee
// RETRIEVE DEPARTURE AND DESTINATION ADDRESS
/*
* For editDepart, I would like to replace it by my Current location
*/
final String editDepart = getIntent().getStringExtra("DEPART");
final String editArrivee = getIntent().getStringExtra("ARRIVEE");
/* Appel de la méthode asynchrone // ASYNCHRONOUS METHOD
* ATTENTION : Il faut que ItineraireTask soit extends AsyncTask<Void, Integer, Boolean>
* Sinon, on ne pourra pas utilise la methode execute() */
new ItineraireTask(this, googlemap, editDepart, editArrivee).execute();
}
}
下面是我的 ItineraireTask
public class ItineraireTask extends AsyncTask<Void, Integer, Boolean>
{
private static final String TOAST_MSG = "Calcul de l'itinéraire en cours";
private static final String TOAST_ERR_MAJ = "Impossible de trouver un itinéraire";
private Context context;
private GoogleMap gMap;
private String editDepart;
private String editArrivee;
private final ArrayList<LatLng> lstLatLng = new ArrayList<LatLng>();
/** CONSTRUCTEUR **/
public ItineraireTask(final Context context, final GoogleMap gMap, final String editDepart, final String editArrivee)
{
this.context = context;
this.gMap= gMap;
this.editDepart = editDepart;
this.editArrivee = editArrivee;
}
protected void onPreExecute()
{
Toast.makeText(context, TOAST_MSG, Toast.LENGTH_LONG).show();
}
protected Boolean doInBackground(Void... params)
{
try
{
//Construction de l'url à appeler
final StringBuilder url = new StringBuilder("http://maps.googleapis.com/maps/api/directions/xml?sensor=false&language=fr");
url.append("&origin=");
url.append(editDepart.replace(' ', '+'));
url.append("&destination=");
url.append(editArrivee.replace(' ', '+'));
//Appel du web service
final InputStream stream = new URL(url.toString()).openStream();
//Traitement des données
final DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
documentBuilderFactory.setIgnoringComments(true);
final DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
final Document document = documentBuilder.parse(stream);
document.getDocumentElement().normalize();
//On récupère d'abord le status de la requête
final String status = document.getElementsByTagName("status").item(0).getTextContent();
if(!"OK".equals(status))
{
return false;
}
//On récupère les steps
final Element elementLeg = (Element) document.getElementsByTagName("leg").item(0);
final NodeList nodeListStep = elementLeg.getElementsByTagName("step");
final int length = nodeListStep.getLength();
for(int i=0; i<length; i++)
{
final Node nodeStep = nodeListStep.item(i);
if(nodeStep.getNodeType() == Node.ELEMENT_NODE)
{
final Element elementStep = (Element) nodeStep;
//On décode les points du XML
decodePolylines(elementStep.getElementsByTagName("points").item(0).getTextContent());
}
}
return true;
}
catch(final Exception e)
{
return false;
}
}
/** METHODE QUI DECODE LES POINTS EN LAT-LONG**/
private void decodePolylines(final String encodedPoints)
{
int index = 0;
int lat = 0, lng = 0;
while (index < encodedPoints.length())
{
int b, shift = 0, result = 0;
do
{
b = encodedPoints.charAt(index++) - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lat += dlat;
shift = 0;
result = 0;
do
{
b = encodedPoints.charAt(index++) - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
lng += dlng;
lstLatLng.add(new LatLng((double)lat/1E5, (double)lng/1E5));
}
}
protected void onPostExecute(final Boolean result)
{
if(!result)
{
Toast.makeText(context, TOAST_ERR_MAJ, Toast.LENGTH_SHORT).show();
}
else
{
//On déclare le polyline, c'est-à-dire le trait (ici bleu) que l'on ajoute sur la carte pour tracer l'itinéraire
final PolylineOptions polylines = new PolylineOptions();
polylines.color(Color.BLUE);
//On construit le polyline
for(final LatLng latLng : lstLatLng)
{
polylines.add(latLng);
}
//On déclare un marker vert que l'on placera sur le départ
final MarkerOptions markerA = new MarkerOptions();
markerA.position(lstLatLng.get(0));
markerA.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN));
//On déclare un marker rouge que l'on mettra sur l'arrivée
final MarkerOptions markerB = new MarkerOptions();
markerB.position(lstLatLng.get(lstLatLng.size()-1));
markerB.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
//On met à jour la carte
gMap.moveCamera(CameraUpdateFactory.newLatLngZoom(lstLatLng.get(0), 10));
gMap.addMarker(markerA);
gMap.addPolyline(polylines);
gMap.addMarker(markerB);
}
}
}
感谢你提前！
最好的问候，
Tofuw
推荐答案
下面是一个博客帖子我就这个话题写了，并且可以帮你这一个：
Here is a blog post I wrote on this topic and that can help you with this one:
有就是可以下载和使用的示例项目。
There is a sample project that you can download and use.
这篇关于Android-谷歌地图V2：从当前位置跟踪路由到其它目的地的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
