Desenhar uma linha / caminho no Google Maps

Há muito tempo estou ocupado descobrindo como traçar uma linha entre dois pontos (GPS) no mapa em HelloMapView, mas sem sorte.

Alguém poderia me dizer como fazer isso.

Suponha que eu use o HelloMapView, que estende o MapView. Preciso usar sobreposições? Nesse caso, tenho que substituir o método onDraw () da sobreposição e desenhar uma linha aqui? Na verdade, tentei essas coisas, mas sem resultado.

Agradeço antecipadamente!

Obrigado pela ajuda. Por fim, consegui traçar uma linha no mapa. Foi assim que eu fiz:

/** Called when the activity is first created. */
private List<Overlay> mapOverlays;

private Projection projection;  

@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(true);

    mapOverlays = mapView.getOverlays();        
    projection = mapView.getProjection();
    mapOverlays.add(new MyOverlay());        

}

@Override
protected boolean isRouteDisplayed() {
    return false;
}

class MyOverlay extends Overlay{

    public MyOverlay(){

    }   

    public void draw(Canvas canvas, MapView mapv, boolean shadow){
        super.draw(canvas, mapv, shadow);

        Paint   mPaint = new Paint();
        mPaint.setDither(true);
        mPaint.setColor(Color.RED);
        mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
        mPaint.setStrokeJoin(Paint.Join.ROUND);
        mPaint.setStrokeCap(Paint.Cap.ROUND);
        mPaint.setStrokeWidth(2);

        GeoPoint gP1 = new GeoPoint(19240000,-99120000);
        GeoPoint gP2 = new GeoPoint(37423157, -122085008);

        Point p1 = new Point();
        Point p2 = new Point();
        Path path = new Path();

        Projection projection=mapv.getProjection();
        projection.toPixels(gP1, p1);
        projection.toPixels(gP2, p2);

        path.moveTo(p2.x, p2.y);
        path.lineTo(p1.x,p1.y);

        canvas.drawPath(path, mPaint);
    }

Para quem realmente quer traçar uma linha simples - existe também a versão curta.

GoogleMap map;
// ... get a map.
// Add a thin red line from London to New York.
Polyline line = map.addPolyline(new PolylineOptions()
    .add(new LatLng(51.5, -0.1), new LatLng(40.7, -74.0))
    .width(5)
    .color(Color.RED));

de https://developers.google.com/maps/documentation/android/reference/com/google/android/gms/maps/model/Polyline

// This Activity will draw a line between two selected points on Map

public class MainActivity extends MapActivity {
 MapView myMapView = null;
 MapController myMC = null;
 GeoPoint geoPoint = null;

 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle savedInstanceState) {


  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  myMapView = (MapView) findViewById(R.id.mapview);
  geoPoint = null;
  myMapView.setSatellite(false);

  String pairs[] = getDirectionData("ahmedabad", "vadodara");
  String[] lngLat = pairs[0].split(",");

  // STARTING POINT
  GeoPoint startGP = new GeoPoint(
    (int) (Double.parseDouble(lngLat[1]) * 1E6), (int) (Double
      .parseDouble(lngLat[0]) * 1E6));

  myMC = myMapView.getController();
  geoPoint = startGP;
  myMC.setCenter(geoPoint);
  myMC.setZoom(15);
  myMapView.getOverlays().add(new DirectionPathOverlay(startGP, startGP));

  // NAVIGATE THE PATH

  GeoPoint gp1;
  GeoPoint gp2 = startGP;

  for (int i = 1; i < pairs.length; i++) {
   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));
   myMapView.getOverlays().add(new DirectionPathOverlay(gp1, gp2));
   Log.d("xxx", "pair:" + pairs[i]);
  }

  // END POINT
  myMapView.getOverlays().add(new DirectionPathOverlay(gp2, gp2));

  myMapView.getController().animateTo(startGP);
  myMapView.setBuiltInZoomControls(true);
  myMapView.displayZoomControls(true);

 }

 @Override
 protected boolean isRouteDisplayed() {
  // TODO Auto-generated method stub
  return false;
 }

 private String[] getDirectionData(String srcPlace, String destPlace) {

  String urlString = "http://maps.google.com/maps?f=d&hl=en&saddr="
   + srcPlace + "&daddr=" + destPlace
   + "&ie=UTF8&0&om=0&output=kml";

  Log.d("URL", urlString);
  Document doc = null;
  HttpURLConnection urlConnection = null;
  URL url = null;
  String pathConent = "";

  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());

  } catch (Exception e) {
  }

  NodeList nl = doc.getElementsByTagName("LineString");
  for (int s = 0; s < nl.getLength(); s++) {
   Node rootNode = nl.item(s);
   NodeList configItems = rootNode.getChildNodes();
   for (int x = 0; x < configItems.getLength(); x++) {
    Node lineStringNode = configItems.item(x);
    NodeList path = lineStringNode.getChildNodes();
    pathConent = path.item(0).getNodeValue();
   }
  }
  String[] tempContent = pathConent.split(" ");
  return tempContent;
 }

}


//*****************************************************************************

DirectionPathOverlay

public class DirectionPathOverlay extends Overlay {

    private GeoPoint gp1;
    private GeoPoint gp2;

    public DirectionPathOverlay(GeoPoint gp1, GeoPoint gp2) {
        this.gp1 = gp1;
        this.gp2 = gp2;
    }

    @Override
    public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
            long when) {
        // TODO Auto-generated method stub
        Projection projection = mapView.getProjection();
        if (shadow == false) {

            Paint paint = new Paint();
            paint.setAntiAlias(true);
            Point point = new Point();
            projection.toPixels(gp1, point);
            paint.setColor(Color.BLUE);
            Point point2 = new Point();
            projection.toPixels(gp2, point2);
            paint.setStrokeWidth(2);
            canvas.drawLine((float) point.x, (float) point.y, (float) point2.x,
                    (float) point2.y, paint);
        }
        return super.draw(canvas, mapView, shadow, when);
    }

    @Override
    public void draw(Canvas canvas, MapView mapView, boolean shadow) {
        // TODO Auto-generated method stub

        super.draw(canvas, mapView, shadow);
    }

}

Este é um código-fonte completo para desenhar o caminho de direção da latitude e longitude de origem até a latitude e longitude de destino. Eu mudei o código acima para se adequar à latitude e longitude em vez de origem e destino. Assim, qualquer pessoa que esteja acessando sua latitude e longitude através de seu GPS pode obter a direção de seu dispositivo de GPS para as coordenadas de destino.

Graças às respostas acima, podemos fazer essa mudança e obter a direção do caminho.

public class DrawMapActivity extends MapActivity {
     MapView myMapView = null;
     MapController myMC = null;
     GeoPoint geoPoint = null;
     @Override
     public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);

      setContentView(R.layout.main);
      myMapView = (MapView) findViewById(R.id.mapview);

      geoPoint = null;
      myMapView.setSatellite(false);
      double fromLat = 12.303534;
      double fromLong = 76.64611;
      double toLat = 12.9715987;
      double toLong = 77.5945627;

      String sourceLat = Double.toString(fromLat);
      String sourceLong = Double.toString(fromLong);
      String destinationLat = Double.toString(toLat);
      String destinationLong = Double.toString(toLong);

      String pairs[] = getDirectionData(sourceLat,sourceLong, destinationLat, destinationLong );
      String[] lngLat = pairs[0].split(",");

      // STARTING POINT
      GeoPoint startGP = new GeoPoint((int) (Double.parseDouble(lngLat[1]) * 1E6), (int) (Double.parseDouble(lngLat[0]) * 1E6));

      myMC = myMapView.getController();
      geoPoint = startGP;
      myMC.setCenter(geoPoint);
      myMC.setZoom(10);
      myMapView.getOverlays().add(new DirectionPathOverlay(startGP, startGP));

      // NAVIGATE THE PATH

      GeoPoint gp1;
      GeoPoint gp2 = startGP;

      for (int i = 1; i < pairs.length; i++) {
       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));
       myMapView.getOverlays().add(new DirectionPathOverlay(gp1, gp2));
       Log.d("xxx", "pair:" + pairs[i]);
      }

      // END POINT
      myMapView.getOverlays().add(new DirectionPathOverlay(gp2, gp2));

      myMapView.getController().animateTo(startGP);
      myMapView.setBuiltInZoomControls(true);
      myMapView.displayZoomControls(true);

     }

     @Override
     protected boolean isRouteDisplayed() {
      // TODO Auto-generated method stub
      return false;
     }

     private String[] getDirectionData(String sourceLat, String sourceLong, String destinationLat, String destinationLong) {


      String urlString = "http://maps.google.com/maps?f=d&hl=en&" +"saddr="+sourceLat+","+sourceLong+"&daddr="+destinationLat+","+destinationLong + "&ie=UTF8&0&om=0&output=kml";
      Log.d("URL", urlString);
      Document doc = null;
      HttpURLConnection urlConnection = null;
      URL url = null;
      String pathConent = "";

      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());

      } catch (Exception e) {
      }

      NodeList nl = doc.getElementsByTagName("LineString");
      for (int s = 0; s < nl.getLength(); s++) {
       Node rootNode = nl.item(s);
       NodeList configItems = rootNode.getChildNodes();
       for (int x = 0; x < configItems.getLength(); x++) {
        Node lineStringNode = configItems.item(x);
        NodeList path = lineStringNode.getChildNodes();
        pathConent = path.item(0).getNodeValue();
       }
      }
      String[] tempContent = pathConent.split(" ");
      return tempContent;
     }

    }


    //*****************************************************************************



     class DirectionPathOverlay extends Overlay {

        private GeoPoint gp1;
        private GeoPoint gp2;

        public DirectionPathOverlay(GeoPoint gp1, GeoPoint gp2) {
            this.gp1 = gp1;
            this.gp2 = gp2;
        }

        @Override
        public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
                long when) {
            // TODO Auto-generated method stub
            Projection projection = mapView.getProjection();
            if (shadow == false) {

                Paint paint = new Paint();
                paint.setAntiAlias(true);
                Point point = new Point();
                projection.toPixels(gp1, point);
                paint.setColor(Color.BLUE);
                Point point2 = new Point();
                projection.toPixels(gp2, point2);
                paint.setStrokeWidth(2);
                canvas.drawLine((float) point.x, (float) point.y, (float) point2.x,(float) point2.y, paint);
            }
            return super.draw(canvas, mapView, shadow, when);
        }

        @Override
        public void draw(Canvas canvas, MapView mapView, boolean shadow) {
            // TODO Auto-generated method stub

            super.draw(canvas, mapView, shadow);
        }

    }

Espero que ajude para outros usuários do Stack Overflow

Isso também pode ser feito usando intents:

  final Intent intent = new Intent(Intent.ACTION_VIEW,
    Uri.parse(
            "http://maps.google.com/maps?" +
            "saddr="+YOUR_START_LONGITUDE+","+YOUR_START_LATITUDE+"&daddr="YOUR_END_LONGITUDE+","+YOUR_END_LATITUDE));
         intent.setClassName(
          "com.google.android.apps.maps",
          "com.google.android.maps.MapsActivity");
   startActivity(intent);

É realmente fácil com Google Maps Android API v2

Basta copiar o exemplo da documentação do desenvolvedor

(é claro que você tem que iniciar seu mapa primeiro)

GoogleMap map;
 // ... get a map.
 // Add a thin red line from London to New York.
 Polyline line = map.addPolyline(new PolylineOptions()
     .add(new LatLng(51.5, -0.1), new LatLng(40.7, -74.0))
     .width(5)
     .color(Color.RED));

Sim, você precisa usar sobreposições.

Você precisa obter as sobreposições do MapView e adicionar sua nova sobreposição a elas.

Sua classe estende Overlay, que é uma tela transparente na qual você pode desenhar como qualquer outra tela.

Você pode usar mapView.getProjection () para obter a projeção da visualização do mapa.

...

Mais informações encontradas aqui: http://blogoscoped.com/archive/2008-12-15-n14.html

Você pode obter a projeção do objeto MapView que é passado para o método draw (): mapv.getProjection (). ToPixels (gP1, p1);

public class MainActivity extends FragmentActivity  {


  List<Overlay> mapOverlays;
  GeoPoint point1, point2;
  LocationManager locManager;
  Drawable drawable;
  Document document;
  GMapV2GetRouteDirection v2GetRouteDirection;
  LatLng fromPosition;
  LatLng toPosition;
  GoogleMap mGoogleMap;
  MarkerOptions markerOptions;
  Location location ;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        v2GetRouteDirection = new GMapV2GetRouteDirection();
      SupportMapFragment supportMapFragment = (SupportMapFragment) getSupportFragmentManager()
        .findFragmentById(R.id.map);
        mGoogleMap = supportMapFragment.getMap();

        // Enabling MyLocation in Google Map
        mGoogleMap.setMyLocationEnabled(true);
        mGoogleMap.getUiSettings().setZoomControlsEnabled(true);
        mGoogleMap.getUiSettings().setCompassEnabled(true);
        mGoogleMap.getUiSettings().setMyLocationButtonEnabled(true);
        mGoogleMap.getUiSettings().setAllGesturesEnabled(true);
        mGoogleMap.setTrafficEnabled(true);
        mGoogleMap.animateCamera(CameraUpdateFactory.zoomTo(12));
        markerOptions = new MarkerOptions();
        fromPosition = new LatLng(11.663837, 78.147297);
        toPosition = new LatLng(11.723512, 78.466287);
        GetRouteTask getRoute = new GetRouteTask();
        getRoute.execute();
  }
  /**
   *
   * @author VIJAYAKUMAR M
   * This class Get Route on the map
   *
   */
  private class GetRouteTask extends AsyncTask<String, Void, String> {

        private ProgressDialog Dialog;
        String response = "";
        @Override
        protected void onPreExecute() {
              Dialog = new ProgressDialog(MainActivity.this);
              Dialog.setMessage("Loading route...");
              Dialog.show();
        }

        @Override
        protected String doInBackground(String... urls) {
              //Get All Route values
                         document = v2GetRouteDirection.getDocument(fromPosition, toPosition,          GMapV2GetRouteDirection.MODE_DRIVING);
                    response = "Success";
              return response;

        }

        @Override
        protected void onPostExecute(String result) {
              mGoogleMap.clear();
              if(response.equalsIgnoreCase("Success")){
              ArrayList<LatLng> directionPoint = v2GetRouteDirection.getDirection(document);
              PolylineOptions rectLine = new PolylineOptions().width(10).color(
                          Color.RED);

              for (int i = 0; i < directionPoint.size(); i++) {
                    rectLine.add(directionPoint.get(i));
              }
              // Adding route on the map
              mGoogleMap.addPolyline(rectLine);
              markerOptions.position(toPosition);
              markerOptions.draggable(true);
              mGoogleMap.addMarker(markerOptions);

              }

              Dialog.dismiss();
        }
  }
  @Override
  protected void onStop() {
        super.onStop();
        finish();
    }
 }

Classe Route Helper

 public class GMapV2GetRouteDirection {
  public final static String MODE_DRIVING = "driving";
  public final static String MODE_WALKING = "walking";

  public GMapV2GetRouteDirection() { }

  public Document getDocument(LatLng start, LatLng end, String mode) {
    String url = "http://maps.googleapis.com/maps/api/directions/xml?"
            + "origin=" + start.latitude + "," + start.longitude 
            + "&destination=" + end.latitude + "," + end.longitude
            + "&sensor=false&units=metric&mode=driving";

    try {
        HttpClient httpClient = new DefaultHttpClient();
        HttpContext localContext = new BasicHttpContext();
        HttpPost httpPost = new HttpPost(url);
        HttpResponse response = httpClient.execute(httpPost, localContext);
        InputStream in = response.getEntity().getContent();
        DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
        Document doc = builder.parse(in);
        return doc;
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
  }

  public String getDurationText (Document doc) {
    NodeList nl1 = doc.getElementsByTagName("duration");
    Node node1 = nl1.item(0);
    NodeList nl2 = node1.getChildNodes();
    Node node2 = nl2.item(getNodeIndex(nl2, "text"));
    Log.i("DurationText", node2.getTextContent());
    return node2.getTextContent();
 }

 public int getDurationValue (Document doc) {
    NodeList nl1 = doc.getElementsByTagName("duration");
    Node node1 = nl1.item(0);
    NodeList nl2 = node1.getChildNodes();
    Node node2 = nl2.item(getNodeIndex(nl2, "value"));
    Log.i("DurationValue", node2.getTextContent());
    return Integer.parseInt(node2.getTextContent());
  }

  public String getDistanceText (Document doc) {
    NodeList nl1 = doc.getElementsByTagName("distance");
    Node node1 = nl1.item(0);
    NodeList nl2 = node1.getChildNodes();
    Node node2 = nl2.item(getNodeIndex(nl2, "text"));
    Log.i("DistanceText", node2.getTextContent());
    return node2.getTextContent();
  }

  public int getDistanceValue (Document doc) {
    NodeList nl1 = doc.getElementsByTagName("distance");
    Node node1 = nl1.item(0);
    NodeList nl2 = node1.getChildNodes();
    Node node2 = nl2.item(getNodeIndex(nl2, "value"));
    Log.i("DistanceValue", node2.getTextContent());
    return Integer.parseInt(node2.getTextContent());
  }

  public String getStartAddress (Document doc) {
    NodeList nl1 = doc.getElementsByTagName("start_address");
    Node node1 = nl1.item(0);
    Log.i("StartAddress", node1.getTextContent());
    return node1.getTextContent();
  }

  public String getEndAddress (Document doc) {
    NodeList nl1 = doc.getElementsByTagName("end_address");
    Node node1 = nl1.item(0);
    Log.i("StartAddress", node1.getTextContent());
    return node1.getTextContent();
  }

  public String getCopyRights (Document doc) {
    NodeList nl1 = doc.getElementsByTagName("copyrights");
    Node node1 = nl1.item(0);
    Log.i("CopyRights", node1.getTextContent());
    return node1.getTextContent();
  }

   public ArrayList<LatLng> getDirection (Document doc) {
    NodeList nl1, nl2, nl3;
    ArrayList<LatLng> listGeopoints = new ArrayList<LatLng>();
    nl1 = doc.getElementsByTagName("step");
    if (nl1.getLength() > 0) {
        for (int i = 0; i < nl1.getLength(); i++) {
            Node node1 = nl1.item(i);
            nl2 = node1.getChildNodes();

            Node locationNode = nl2.item(getNodeIndex(nl2, "start_location"));
            nl3 = locationNode.getChildNodes();
            Node latNode = nl3.item(getNodeIndex(nl3, "lat"));
            double lat = Double.parseDouble(latNode.getTextContent());
            Node lngNode = nl3.item(getNodeIndex(nl3, "lng"));
            double lng = Double.parseDouble(lngNode.getTextContent());
            listGeopoints.add(new LatLng(lat, lng));

            locationNode = nl2.item(getNodeIndex(nl2, "polyline"));
            nl3 = locationNode.getChildNodes();
            latNode = nl3.item(getNodeIndex(nl3, "points"));
            ArrayList<LatLng> arr = decodePoly(latNode.getTextContent());
            for(int j = 0 ; j < arr.size() ; j++) {
                listGeopoints.add(new LatLng(arr.get(j).latitude, arr.get(j).longitude));
            }

            locationNode = nl2.item(getNodeIndex(nl2, "end_location"));
            nl3 = locationNode.getChildNodes();
            latNode = nl3.item(getNodeIndex(nl3, "lat"));
            lat = Double.parseDouble(latNode.getTextContent());
            lngNode = nl3.item(getNodeIndex(nl3, "lng"));
            lng = Double.parseDouble(lngNode.getTextContent());
            listGeopoints.add(new LatLng(lat, lng));
        }
    }

    return listGeopoints;
 }

 private int getNodeIndex(NodeList nl, String nodename) {
    for(int i = 0 ; i < nl.getLength() ; i++) {
        if(nl.item(i).getNodeName().equals(nodename))
            return i;
    }
    return -1;
 }

 private ArrayList<LatLng> decodePoly(String encoded) {
    ArrayList<LatLng> poly = new ArrayList<LatLng>();
    int index = 0, len = encoded.length();
    int lat = 0, lng = 0;
    while (index < len) {
        int b, shift = 0, result = 0;
        do {
            b = encoded.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 = encoded.charAt(index++) - 63;
            result |= (b & 0x1f) << shift;
            shift += 5;
        } while (b >= 0x20);
        int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
        lng += dlng;

        LatLng position = new LatLng((double) lat / 1E5, (double) lng / 1E5);
        poly.add(position);
    }
    return poly;
  }
 }

só vou encontrar desenhar com algum retângulo em mapviewapenas queremos mudar a pintura como gostamos

EmptyOverlay.java

public class EmptyOverlay extends Overlay {
private float x1,y1;
private MapExampleActivity mv = null;
private Overlay overlay = null;

public EmptyOverlay(MapExampleActivity mapV){
    mv = mapV;
}

@Override
public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
        long when) {
    // TODO Auto-generated method stub
    return super.draw(canvas, mapView, shadow, when);
}

@Override
public boolean onTouchEvent(MotionEvent e, MapView mapView) {
    if(mv.isEditMode()){
        if(e.getAction() == MotionEvent.ACTION_DOWN){
            //when user presses the map add a new overlay to the map
            //move events will be catched by newly created overlay
            x1 = y1 = 0;
            x1 = e.getX();
            y1 = e.getY();

            overlay = new MapOverlay(mv, x1, y1);
            mapView.getOverlays().add(overlay);

        }
        if(e.getAction() == MotionEvent.ACTION_MOVE){
        }
        //---when user lifts his finger---
        if (e.getAction() == MotionEvent.ACTION_UP) {                

        }    
        return true;
    }
    return false;
}
}

MapExampleActivity.java

 public class MapExampleActivity extends MapActivity {
private MapView mapView;
private boolean isEditMode = false;
private Button toogle;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    toogle = (Button)findViewById(R.id.toogleMap);        
    toogle.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            toogleEditMode();

        }
    });

    mapView = (MapView)findViewById(R.id.mapview);
    mapView.setBuiltInZoomControls(true); //display zoom controls
    //add one empty overlay acting as a overlay loader. This will catch press events and will add the actual overlays
    mapView.getOverlays().add(new EmptyOverlay(this));
    mapView.postInvalidate();
}
//toogle edit mode for drawing or navigating the map
private void toogleEditMode(){
    isEditMode = !isEditMode;
}

@Override
protected boolean isRouteDisplayed() {
    // TODO Auto-generated method stub
    return false;
}
@Override
protected boolean isLocationDisplayed() {
    return false;
}

public boolean isEditMode(){
    return this.isEditMode;
}

public MapView getMapView(){
    return this.mapView;
}
}

MapOverlay.java

 public class MapOverlay extends Overlay {

private float x1,y1,x2,y2;
private GeoPoint p1=null,p2=null;
private MapExampleActivity mv = null;
private Paint paint = new Paint();
private boolean isUp = false;

//constructor receiving the initial point
public MapOverlay(MapExampleActivity mapV,float x,float y){
    paint.setStrokeWidth(2.0f);
    x1 = x;
    y1 = y;
    mv = mapV;
    p1 = mapV.getMapView().getProjection().fromPixels((int)x1,(int)y1);
}
//override draw method to add our custom drawings
@Override
public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
        long when) {

    if(p1 != null && p2 != null){
        //get the 2 geopoints defining the area and transform them to pixels
        //this way if we move or zoom the map rectangle will follow accordingly
        Point screenPts1 = new Point();
        mapView.getProjection().toPixels(p1, screenPts1);
        Point screenPts2 = new Point();
        mapView.getProjection().toPixels(p2, screenPts2);

        //draw inner rectangle
        paint.setColor(0x4435EF56);
        paint.setStyle(Style.FILL);
        canvas.drawRect(screenPts1.x, screenPts1.y, screenPts2.x, screenPts2.y, paint);
        //draw outline rectangle
        paint.setColor(0x88158923);
        paint.setStyle(Style.STROKE);
        canvas.drawRect(screenPts1.x, screenPts1.y, screenPts2.x, screenPts2.y, paint);
    }
    return true;
}

@Override
public boolean onTouchEvent(MotionEvent e, MapView mapView) {
    if(mv.isEditMode() && !isUp){
        if(e.getAction() == MotionEvent.ACTION_DOWN){
            x1 = y1 = 0;
            x1 = e.getX();
            y1 = e.getY();
            p1 = mapView.getProjection().fromPixels((int)x1,(int)y1);

        }
        //here we constantly change geopoint p2 as we move out finger
        if(e.getAction() == MotionEvent.ACTION_MOVE){
            x2 = e.getX();
            y2 = e.getY();
            p2 = mapView.getProjection().fromPixels((int)x2,(int)y2);

        }
        //---when user lifts his finger---
        if (e.getAction() == MotionEvent.ACTION_UP) {                
            isUp = true;
        }    
        return true;
    }
    return false;
}
 }

consulte http://n3vrax.wordpress.com/2011/08/13/drawing-overlays-on-android-map-view/

Try this one:
Add itemizedOverlay class:

public class AndroidGoogleMapsActivity extends MapActivity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Displaying Zooming controls
        MapView mapView = (MapView) findViewById(R.id.mapview);
        mapView.setBuiltInZoomControls(true);


        MapController mc = mapView.getController();
        double lat = Double.parseDouble("48.85827758964043");
        double lon = Double.parseDouble("2.294543981552124");
        GeoPoint geoPoint = new GeoPoint((int)(lat * 1E6), (int)(lon * 1E6));
        mc.animateTo(geoPoint);
        mc.setZoom(15);
        mapView.invalidate(); 


        /**
         * Placing Marker
         * */
        List<Overlay> mapOverlays = mapView.getOverlays();
        Drawable drawable = this.getResources().getDrawable(R.drawable.mark_red);
        AddItemizedOverlay itemizedOverlay = 
             new AddItemizedOverlay(drawable, this);


        OverlayItem overlayitem = new OverlayItem(geoPoint, "Hello", "Sample Overlay item");

        itemizedOverlay.addOverlay(overlayitem);
        mapOverlays.add(itemizedOverlay);

    }

    @Override
    protected boolean isRouteDisplayed() {
        return false;
    }
}

Simplesmente pegue a rota deste url e faça a seguir ...

Origem ---> ponto de partida, latitude e longitude

Destino ---> ponto final, latitude e longitude

aqui eu coloquei origem como latitude Delhi e longitude e destino como latitude longitude chandigarh

https://maps.googleapis.com/maps/api/directions/json?origin=28.704060,77.102493&destination=30.733315,76.779419&sensor=false&key= "COLOQUE SUA CHAVE API DO MAPA"

Isso funcionou para mim. Com o método mencionado aqui, consegui desenhar polilinhas no Google Maps V2. Desenhei uma nova linha sempre que a localização do usuário era alterada, de modo que a polilinha se parecia com o caminho seguido pelo usuário no mapa.

Código-fonte em. Github: prasang7 / eTaxi-Meter

Por favor, ignore outros módulos deste projeto relacionados ao cálculo de distância e interface do usuário se você não estiver interessado neles.