Drawing a line/path on Google Maps

小开

是的，您需要使用覆盖。

您需要获得 MapView 的覆盖图并添加新的覆盖图到其中。

您的类扩展 Overlay，它是一个透明的画布，您可以像在其他画布上一样在其上绘制。

可以使用 mapView.getProject()获得地图视图的投影。

...

更多信息请点击: http://blogoscoped.com/archive/2008-12-15-n14.html

小开

最佳答案

谢谢你的帮助，我终于可以在地图上画一条线了。我是这么做的:

/** 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);
}

小开

你可以从 MapView 对象中得到投影，这个对象被传递到 draw ()方法中: GetProject() . toPixels (gP1，p1) ;

小开

// 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);
}


}

小开

这是绘制从源经纬度到目标经纬度的方向路径的完整源代码。我更改了上述代码，以适应经纬度，而不是源地和目的地。所以任何通过 gps 访问他的经纬度的人都可以从他的 gps 设备获得到目的地坐标的方向。

由于以上的答案，我们可以做出这样的改变，并得到路径的方向。

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);
}


}

希望对其他 Stack Overflow 用户有所帮助

小开

这也可以通过使用意图来实现:

  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);

小开

只是我会找到一些矩形画在 mapview只是我们想改变油漆，因为我们喜欢

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;
}
}

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;
}
}

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

小开

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;
}
}

小开

It is really easy with Google Maps Android API v2

只需复制开发人员文档中的示例

(当然你必须先初始化你的地图)

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));

小开

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();
}
}

路线辅助工程类别

 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;
}
}

小开

对于那些 真的只有想要画一条简单的线的人来说——确实也有简短的版本。

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));

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

小开

这招对我很管用。使用这里提到的方法，我能够在 Google Maps V2上绘制多边形。每当用户位置发生变化时，我都会画一条新的线，这样折线看起来就像用户在地图上所遵循的路径。

源代码。 Github: prasang7/eTaxi-Meter

请忽略这个项目相关的距离计算和用户界面的其他模块，如果你不感兴趣。

小开

只需从这个网址获取路由，然后执行下一步..。

Origin ---> starting point latitude & longitude

目的地-> 终点经纬度

在这里我把原产地和目的地写成了德里经纬度和昌迪加尔经纬度

https://maps.googleapis.com/maps/api/directions/json?origin=28.704060,77.102493&destination=30.733315,76.779419&sensor=false&key="PUT YOUR MAP API KEY"