我在我的 android 应用程序中使用 google map api v2，我能够显示地图并在其上放置标记，但现在我遇到了需要找出两个标记或点之间的距离的问题放在地图上，我已经浏览了文档，但在这种情况下没有发现任何帮助。
如果有人知道如何解决这个问题，请帮助我。
谢谢
【问题讨论】：
在Google Map API V2 中，您有LatLng 对象，因此您不能使用distanceTo（目前）。
考虑到 oldPosition 和 newPosition 是 LatLng 对象，您可以使用以下代码：
// The computed distance is stored in results[0].
//If results has length 2 or greater, the initial bearing is stored in results[1].
//If results has length 3 or greater, the final bearing is stored in results[2].
float[] results = new float[1];
Location.distanceBetween(oldPosition.latitude, oldPosition.longitude,
newPosition.latitude, newPosition.longitude, results);
有关Location 类的更多信息请参阅this link
【讨论】：
你可以使用下面的方法来给你准确的结果
public double CalculationByDistance(LatLng StartP, LatLng EndP) {
int Radius = 6371;// radius of earth in Km
double lat1 = StartP.latitude;
double lat2 = EndP.latitude;
double lon1 = StartP.longitude;
double lon2 = EndP.longitude;
double dLat = Math.toRadians(lat2 - lat1);
double dLon = Math.toRadians(lon2 - lon1);
double a = Math.sin(dLat / 2) * Math.sin(dLat / 2)
+ Math.cos(Math.toRadians(lat1))
* Math.cos(Math.toRadians(lat2)) * Math.sin(dLon / 2)
* Math.sin(dLon / 2);
double c = 2 * Math.asin(Math.sqrt(a));
double valueResult = Radius * c;
double km = valueResult / 1;
DecimalFormat newFormat = new DecimalFormat("####");
int kmInDec = Integer.valueOf(newFormat.format(km));
double meter = valueResult % 1000;
int meterInDec = Integer.valueOf(newFormat.format(meter));
Log.i("Radius Value", "" + valueResult + " KM " + kmInDec
+ " Meter " + meterInDec);
return Radius * c;
}
【讨论】：
c？ c 是做什么的？
您应该使用 android 位置
你可以这样做：
location1.distanceTo(location2);
还有：
float[] results = new float[1];
Location.distanceBetween(latLongA.latitude, latLongA.longitude,
latLongB.latitude, latLongB.longitude,
results);
您将获得 location1 和 location2 之间的距离（以米为单位）。 在 latLongA 蚂蚁 latLongB 之间。
使用location。
【讨论】：
Location 对象
来晚了，但看到这是 Google 搜索该主题的热门结果之一，我将以另一种方式分享：
在 Google 中使用单行实用程序类 SphericalUtil
SphericalUtil.computeDistanceBetween(latLngFrom, latLngTo)
您将需要utility classes。
您可以使用 gradle 简单地将它们包含在您的项目中：
implementation 'com.google.maps.android:android-maps-utils:0.5+'
【讨论】：
所有这些答案都会为您提供直线距离。如果您需要通过公路获取距离，则必须解析 Google 在调用他的服务后发回给您的 JSON。你可以使用这个方法：
public String getDistance(final double lat1, final double lon1, final double lat2, final double lon2){
String parsedDistance;
String response;
Thread thread=new Thread(new Runnable() {
@Override
public void run() {
try {
URL url = new URL("http://maps.googleapis.com/maps/api/directions/json?origin=" + lat1 + "," + lon1 + "&destination=" + lat2 + "," + lon2 + "&sensor=false&units=metric&mode=driving");
final HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
InputStream in = new BufferedInputStream(conn.getInputStream());
response = org.apache.commons.io.IOUtils.toString(in, "UTF-8");
JSONObject jsonObject = new JSONObject(response);
JSONArray array = jsonObject.getJSONArray("routes");
JSONObject routes = array.getJSONObject(0);
JSONArray legs = routes.getJSONArray("legs");
JSONObject steps = legs.getJSONObject(0);
JSONObject distance = steps.getJSONObject("distance");
parsedDistance=distance.getString("text");
} catch (ProtocolException e) {
e.printStackTrace();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
}
});
thread.start();
try {
thread.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
return parsedDistance;
}
lat1 和 lon1 是起点坐标，lat2 和 lon2 是目的地坐标。
【讨论】：
@salman khan Usman Kurd 的建议是完美的。我发现唯一可以纠正的是“对于谷歌地图 v2，我们使用 LatLng 类。所以下面是可用于谷歌地图 v2 的 Usman Kurd 的代码。我检查它工作正常。
public double CalculationByDistance(LatLng StartP, LatLng EndP) {
int Radius=6371;//radius of earth in Km
double lat1 = StartP.latitude;
double lat2 = EndP.latitude;
double lon1 = StartP.longitude;
double lon2 = EndP.longitude;
double dLat = Math.toRadians(lat2-lat1);
double dLon = Math.toRadians(lon2-lon1);
double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2)) *
Math.sin(dLon/2) * Math.sin(dLon/2);
double c = 2 * Math.asin(Math.sqrt(a));
double valueResult= Radius*c;
double km=valueResult/1;
DecimalFormat newFormat = new DecimalFormat("####");
int kmInDec = Integer.valueOf(newFormat.format(km));
double meter=valueResult%1000;
int meterInDec= Integer.valueOf(newFormat.format(meter));
Log.i("Radius Value",""+valueResult+" KM "+kmInDec+" Meter "+meterInDec);
return Radius * c;
}
【讨论】：
计算两个地理点之间距离的简单实用函数：
public static long getDistanceMeters(double lat1, double lng1, double lat2, double lng2) {
double l1 = toRadians(lat1);
double l2 = toRadians(lat2);
double g1 = toRadians(lng1);
double g2 = toRadians(lng2);
double dist = acos(sin(l1) * sin(l2) + cos(l1) * cos(l2) * cos(g1 - g2));
if(dist < 0) {
dist = dist + Math.PI;
}
return Math.round(dist * 6378100);
}
【讨论】：
public class GoogleDirection {
public final static String MODE_DRIVING = "driving";
public final static String MODE_WALKING = "walking";
public final static String MODE_BICYCLING = "bicycling";
public final static String STATUS_OK = "OK";
public final static String STATUS_NOT_FOUND = "NOT_FOUND";
public final static String STATUS_ZERO_RESULTS = "ZERO_RESULTS";
public final static String STATUS_MAX_WAYPOINTS_EXCEEDED = "MAX_WAYPOINTS_EXCEEDED";
public final static String STATUS_INVALID_REQUEST = "INVALID_REQUEST";
public final static String STATUS_OVER_QUERY_LIMIT = "OVER_QUERY_LIMIT";
public final static String STATUS_REQUEST_DENIED = "REQUEST_DENIED";
public final static String STATUS_UNKNOWN_ERROR = "UNKNOWN_ERROR";
public final static int SPEED_VERY_FAST = 1;
public final static int SPEED_FAST = 2;
public final static int SPEED_NORMAL = 3;
public final static int SPEED_SLOW = 4;
public final static int SPEED_VERY_SLOW = 5;
private OnDirectionResponseListener mDirectionListener = null;
private OnAnimateListener mAnimateListener = null;
private boolean isLogging = false;
private LatLng animateMarkerPosition = null;
private LatLng beginPosition = null;
private LatLng endPosition = null;
private ArrayList<LatLng> animatePositionList = null;
private Marker animateMarker = null;
private Polyline animateLine = null;
private GoogleMap gm = null;
private int step = -1;
private int animateSpeed = -1;
private int zoom = -1;
private double animateDistance = -1;
private double animateCamera = -1;
private double totalAnimateDistance = 0;
private boolean cameraLock = false;
private boolean drawMarker = false;
private boolean drawLine = false;
private boolean flatMarker = false;
private boolean isCameraTilt = false;
private boolean isCameraZoom = false;
private boolean isAnimated = false;
private Context mContext = null;
public GoogleDirection(Context context) {
mContext = context;
}
public String request(LatLng start, LatLng end, String mode) {
final 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=" + mode;
if(isLogging)
Log.i("GoogleDirection", "URL : " + url);
new RequestTask().execute(new String[]{ url });
return url;
}
private class RequestTask extends AsyncTask<String, Void, Document> {
protected Document doInBackground(String... url) {
try {
HttpClient httpClient = new DefaultHttpClient();
HttpContext localContext = new BasicHttpContext();
HttpPost httpPost = new HttpPost(url[0]);
HttpResponse response = httpClient.execute(httpPost, localContext);
InputStream in = response.getEntity().getContent();
DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
return builder.parse(in);
} catch (IOException e) {
e.printStackTrace();
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(Document doc) {
super.onPostExecute(doc);
if(mDirectionListener != null)
mDirectionListener.onResponse(getStatus(doc), doc, GoogleDirection.this);
}
private String getStatus(Document doc) {
NodeList nl1 = doc.getElementsByTagName("status");
Node node1 = nl1.item(0);
if(isLogging)
Log.i("GoogleDirection", "Status : " + node1.getTextContent());
return node1.getTextContent();
}
}
public void setLogging(boolean state) {
isLogging = state;
}
public String getStatus(Document doc) {
NodeList nl1 = doc.getElementsByTagName("status");
Node node1 = nl1.item(0);
if(isLogging)
Log.i("GoogleDirection", "Status : " + node1.getTextContent());
return node1.getTextContent();
}
public String[] getDurationText(Document doc) {
NodeList nl1 = doc.getElementsByTagName("duration");
String[] arr_str = new String[nl1.getLength() - 1];
for(int i = 0 ; i < nl1.getLength() - 1 ; i++) {
Node node1 = nl1.item(i);
NodeList nl2 = node1.getChildNodes();
Node node2 = nl2.item(getNodeIndex(nl2, "text"));
arr_str[i] = node2.getTextContent();
if(isLogging)
Log.i("GoogleDirection", "DurationText : " + node2.getTextContent());
}
return arr_str;
}
public int[] getDurationValue(Document doc) {
NodeList nl1 = doc.getElementsByTagName("duration");
int[] arr_int = new int[nl1.getLength() - 1];
for(int i = 0 ; i < nl1.getLength() - 1 ; i++) {
Node node1 = nl1.item(i);
NodeList nl2 = node1.getChildNodes();
Node node2 = nl2.item(getNodeIndex(nl2, "value"));
arr_int[i] = Integer.parseInt(node2.getTextContent());
if(isLogging)
Log.i("GoogleDirection", "Duration : " + node2.getTextContent());
}
return arr_int;
}
public String getTotalDurationText(Document doc) {
NodeList nl1 = doc.getElementsByTagName("duration");
Node node1 = nl1.item(nl1.getLength() - 1);
NodeList nl2 = node1.getChildNodes();
Node node2 = nl2.item(getNodeIndex(nl2, "text"));
if(isLogging)
Log.i("GoogleDirection", "TotalDuration : " + node2.getTextContent());
return node2.getTextContent();
}
public int getTotalDurationValue(Document doc) {
NodeList nl1 = doc.getElementsByTagName("duration");
Node node1 = nl1.item(nl1.getLength() - 1);
NodeList nl2 = node1.getChildNodes();
Node node2 = nl2.item(getNodeIndex(nl2, "value"));
if(isLogging)
Log.i("GoogleDirection", "TotalDuration : " + node2.getTextContent());
return Integer.parseInt(node2.getTextContent());
}
public String[] getDistanceText(Document doc) {
NodeList nl1 = doc.getElementsByTagName("distance");
String[] arr_str = new String[nl1.getLength() - 1];
for(int i = 0 ; i < nl1.getLength() - 1 ; i++) {
Node node1 = nl1.item(i);
NodeList nl2 = node1.getChildNodes();
Node node2 = nl2.item(getNodeIndex(nl2, "text"));
arr_str[i] = node2.getTextContent();
if(isLogging)
Log.i("GoogleDirection", "DurationText : " + node2.getTextContent());
}
return arr_str;
}
public int[] getDistanceValue(Document doc) {
NodeList nl1 = doc.getElementsByTagName("distance");
int[] arr_int = new int[nl1.getLength() - 1];
for(int i = 0 ; i < nl1.getLength() - 1 ; i++) {
Node node1 = nl1.item(i);
NodeList nl2 = node1.getChildNodes();
Node node2 = nl2.item(getNodeIndex(nl2, "value"));
arr_int[i] = Integer.parseInt(node2.getTextContent());
if(isLogging)
Log.i("GoogleDirection", "Duration : " + node2.getTextContent());
}
return arr_int;
}
public String getTotalDistanceText(Document doc) {
NodeList nl1 = doc.getElementsByTagName("distance");
Node node1 = nl1.item(nl1.getLength() - 1);
NodeList nl2 = node1.getChildNodes();
Node node2 = nl2.item(getNodeIndex(nl2, "text"));
if(isLogging)
Log.i("GoogleDirection", "TotalDuration : " + node2.getTextContent());
return node2.getTextContent();
}
public int getTotalDistanceValue(Document doc) {
NodeList nl1 = doc.getElementsByTagName("distance");
Node node1 = nl1.item(nl1.getLength() - 1);
NodeList nl2 = node1.getChildNodes();
Node node2 = nl2.item(getNodeIndex(nl2, "value"));
if(isLogging)
Log.i("GoogleDirection", "TotalDuration : " + node2.getTextContent());
return Integer.parseInt(node2.getTextContent());
}
public String getStartAddress(Document doc) {
NodeList nl1 = doc.getElementsByTagName("start_address");
Node node1 = nl1.item(0);
if(isLogging)
Log.i("GoogleDirection", "StartAddress : " + node1.getTextContent());
return node1.getTextContent();
}
public String getEndAddress(Document doc) {
NodeList nl1 = doc.getElementsByTagName("end_address");
Node node1 = nl1.item(0);
if(isLogging)
Log.i("GoogleDirection", "StartAddress : " + node1.getTextContent());
return node1.getTextContent();
}
public String getCopyRights(Document doc) {
NodeList nl1 = doc.getElementsByTagName("copyrights");
Node node1 = nl1.item(0);
if(isLogging)
Log.i("GoogleDirection", "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;
}
public ArrayList<LatLng> getSection(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, "end_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));
}
}
return listGeopoints;
}
public PolylineOptions getPolyline(Document doc, int width, int color) {
ArrayList<LatLng> arr_pos = getDirection(doc);
PolylineOptions rectLine = new PolylineOptions().width(dpToPx(width)).color(color);
for(int i = 0 ; i < arr_pos.size() ; i++)
rectLine.add(arr_pos.get(i));
return rectLine;
}
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;
}
private int dpToPx(int dp) {
DisplayMetrics displayMetrics = mContext.getResources().getDisplayMetrics();
int px = Math.round(dp * (displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT));
return px;
}
public void setOnDirectionResponseListener(OnDirectionResponseListener listener) {
mDirectionListener = listener;
}
public void setOnAnimateListener(OnAnimateListener listener) {
mAnimateListener = listener;
}
public interface OnDirectionResponseListener {
public void onResponse(String status, Document doc, GoogleDirection gd);
}
public interface OnAnimateListener {
public void onFinish();
public void onStart();
public void onProgress(int progress, int total);
}
public void animateDirection(GoogleMap gm, ArrayList<LatLng> direction, int speed
, boolean cameraLock, boolean isCameraTilt, boolean isCameraZoom
, boolean drawMarker, MarkerOptions mo, boolean flatMarker
, boolean drawLine, PolylineOptions po) {
if(direction.size() > 1) {
isAnimated = true;
animatePositionList = direction;
animateSpeed = speed;
this.drawMarker = drawMarker;
this.drawLine = drawLine;
this.flatMarker = flatMarker;
this.isCameraTilt = isCameraTilt;
this.isCameraZoom = isCameraZoom;
step = 0;
this.cameraLock = cameraLock;
this.gm = gm;
setCameraUpdateSpeed(speed);
beginPosition = animatePositionList.get(step);
endPosition = animatePositionList.get(step + 1);
animateMarkerPosition = beginPosition;
if(mAnimateListener != null)
mAnimateListener.onProgress(step, animatePositionList.size());
if(cameraLock) {
float bearing = getBearing(beginPosition, endPosition);
CameraPosition.Builder cameraBuilder = new CameraPosition.Builder()
.target(animateMarkerPosition).bearing(bearing);
if(isCameraTilt)
cameraBuilder.tilt(90);
else
cameraBuilder.tilt(gm.getCameraPosition().tilt);
if(isCameraZoom)
cameraBuilder.zoom(zoom);
else
cameraBuilder.zoom(gm.getCameraPosition().zoom);
CameraPosition cameraPosition = cameraBuilder.build();
gm.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
}
if(drawMarker) {
if(mo != null)
animateMarker = gm.addMarker(mo.position(beginPosition));
else
animateMarker = gm.addMarker(new MarkerOptions().position(beginPosition));
if(flatMarker) {
animateMarker.setFlat(true);
float rotation = getBearing(animateMarkerPosition, endPosition) + 180;
animateMarker.setRotation(rotation);
}
}
if(drawLine) {
if(po != null)
animateLine = gm.addPolyline(po.add(beginPosition)
.add(beginPosition).add(endPosition)
.width(dpToPx((int)po.getWidth())));
else
animateLine = gm.addPolyline(new PolylineOptions()
.width(dpToPx(5)));
}
new Handler().postDelayed(r, speed);
if(mAnimateListener != null)
mAnimateListener.onStart();
}
}
public void cancelAnimated() {
isAnimated = false;
}
public boolean isAnimated() {
return isAnimated;
}
private Runnable r = new Runnable() {
public void run() {
animateMarkerPosition = getNewPosition(animateMarkerPosition, endPosition);
if(drawMarker)
animateMarker.setPosition(animateMarkerPosition);
if(drawLine) {
List<LatLng> points = animateLine.getPoints();
points.add(animateMarkerPosition);
animateLine.setPoints(points);
}
if((animateMarkerPosition.latitude == endPosition.latitude
&& animateMarkerPosition.longitude == endPosition.longitude)) {
if(step == animatePositionList.size() - 2) {
isAnimated = false;
totalAnimateDistance = 0;
if(mAnimateListener != null)
mAnimateListener.onFinish();
} else {
step++;
beginPosition = animatePositionList.get(step);
endPosition = animatePositionList.get(step + 1);
animateMarkerPosition = beginPosition;
if(flatMarker && step + 3 < animatePositionList.size() - 1) {
float rotation = getBearing(animateMarkerPosition, animatePositionList.get(step + 3)) + 180;
animateMarker.setRotation(rotation);
}
if(mAnimateListener != null)
mAnimateListener.onProgress(step, animatePositionList.size());
}
}
if(cameraLock && (totalAnimateDistance > animateCamera || !isAnimated)) {
totalAnimateDistance = 0;
float bearing = getBearing(beginPosition, endPosition);
CameraPosition.Builder cameraBuilder = new CameraPosition.Builder()
.target(animateMarkerPosition).bearing(bearing);
if(isCameraTilt)
cameraBuilder.tilt(90);
else
cameraBuilder.tilt(gm.getCameraPosition().tilt);
if(isCameraZoom)
cameraBuilder.zoom(zoom);
else
cameraBuilder.zoom(gm.getCameraPosition().zoom);
CameraPosition cameraPosition = cameraBuilder.build();
gm.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
}
if(isAnimated) {
new Handler().postDelayed(r, animateSpeed);
}
}
};
public Marker getAnimateMarker() {
return animateMarker;
}
public Polyline getAnimatePolyline() {
return animateLine;
}
private LatLng getNewPosition(LatLng begin, LatLng end) {
double lat = Math.abs(begin.latitude - end.latitude);
double lng = Math.abs(begin.longitude - end.longitude);
double dis = Math.sqrt(Math.pow(lat, 2) + Math.pow(lng, 2));
if(dis >= animateDistance) {
double angle = -1;
if(begin.latitude <= end.latitude && begin.longitude <= end.longitude)
angle = Math.toDegrees(Math.atan(lng / lat));
else if(begin.latitude > end.latitude && begin.longitude <= end.longitude)
angle = (90 - Math.toDegrees(Math.atan(lng / lat))) + 90;
else if(begin.latitude > end.latitude && begin.longitude > end.longitude)
angle = Math.toDegrees(Math.atan(lng / lat)) + 180;
else if(begin.latitude <= end.latitude && begin.longitude > end.longitude)
angle = (90 - Math.toDegrees(Math.atan(lng / lat))) + 270;
double x = Math.cos(Math.toRadians(angle)) * animateDistance;
double y = Math.sin(Math.toRadians(angle)) * animateDistance;
totalAnimateDistance += animateDistance;
double finalLat = begin.latitude + x;
double finalLng = begin.longitude + y;
return new LatLng(finalLat, finalLng);
} else {
return end;
}
}
private float getBearing(LatLng begin, LatLng end) {
double lat = Math.abs(begin.latitude - end.latitude);
double lng = Math.abs(begin.longitude - end.longitude);
if(begin.latitude < end.latitude && begin.longitude < end.longitude)
return (float)(Math.toDegrees(Math.atan(lng / lat)));
else if(begin.latitude >= end.latitude && begin.longitude < end.longitude)
return (float)((90 - Math.toDegrees(Math.atan(lng / lat))) + 90);
else if(begin.latitude >= end.latitude && begin.longitude >= end.longitude)
return (float)(Math.toDegrees(Math.atan(lng / lat)) + 180);
else if(begin.latitude < end.latitude && begin.longitude >= end.longitude)
return (float)((90 - Math.toDegrees(Math.atan(lng / lat))) + 270);
return -1;
}
public void setCameraUpdateSpeed(int speed) {
if(speed == SPEED_VERY_SLOW) {
animateDistance = 0.000005;
animateSpeed = 20;
animateCamera = 0.0004;
zoom = 19;
} else if(speed == SPEED_SLOW) {
animateDistance = 0.00001;
animateSpeed = 20;
animateCamera = 0.0008;
zoom = 18;
} else if(speed == SPEED_NORMAL) {
animateDistance = 0.00005;
animateSpeed = 20;
animateCamera = 0.002;
zoom = 16;
} else if(speed == SPEED_FAST) {
animateDistance = 0.0001;
animateSpeed = 20;
animateCamera = 0.004;
zoom = 15;
} else if(speed == SPEED_VERY_FAST) {
animateDistance = 0.0005;
animateSpeed = 20;
animateCamera = 0.004;
zoom = 13;
} else {
animateDistance = 0.00005;
animateSpeed = 20;
animateCamera = 0.002;
zoom = 16;
}
}
}
//主要活动
public class MapActivity extends ActionBarActivity {
GoogleMap map = null;
GoogleDirection gd;
LatLng start,end;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_map);
start = new LatLng(13.744246499553903, 100.53428772836924);
end = new LatLng(13.751279688694071, 100.54316081106663);
map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();
map.animateCamera(CameraUpdateFactory.newLatLngZoom(start, 15));
gd = new GoogleDirection(this);
gd.setOnDirectionResponseListener(new GoogleDirection.OnDirectionResponseListener() {
public void onResponse(String status, Document doc, GoogleDirection gd) {
Toast.makeText(getApplicationContext(), status, Toast.LENGTH_SHORT).show();
gd.animateDirection(map, gd.getDirection(doc), GoogleDirection.SPEED_FAST
, true, true, true, false, null, false, true, new PolylineOptions().width(8).color(Color.RED));
map.addMarker(new MarkerOptions().position(start)
.icon(BitmapDescriptorFactory.fromResource(R.drawable.markera)));
map.addMarker(new MarkerOptions().position(end)
.icon(BitmapDescriptorFactory.fromResource(R.drawable.markerb)));
String TotalDistance = gd.getTotalDistanceText(doc);
String TotalDuration = gd.getTotalDurationText(doc);
}
});
gd.request(start, end, GoogleDirection.MODE_DRIVING);
}
}
【讨论】：
试试这个
double distance;
Location locationA = new Location("");
locationA.setLatitude(main_Latitude);
locationA.setLongitude(main_Longitude);
Location locationB = new Location("");
locationB.setLatitude(sub_Latitude);
locationB.setLongitude(sub_Longitude);
distance = locationA.distanceTo(locationB)/1000;
kmeter.setText(String.valueOf(distance));
Toast.makeText(getApplicationContext(), ""+distance, Toast.LENGTH_LONG).show();double distance;
【讨论】：
使用 Haversine formula 可以找到两个地理坐标之间的距离。这个公式可以有效地计算球体中的距离，在我们的例子中是地球。
【讨论】：
这是确定时长和距离的简单而完美的代码
第 1 步；（添加此内容并在您的 gradle 中同步）
implementation 'com.android.volley:volley:1.0.0'
第 2 步：（在您的触发方法中写入）
public void clicked(View view) throws JSONException {
JSONObject locationJsonObject = new JSONObject();
locationJsonObject.put("origin", "54.406505,18.67708");
locationJsonObject.put("destination", "54.446251,18.570993");
LatlngCalc(locationJsonObject);
}
第 3 步：（在您的班级中复制和粘贴）
private void LatlngCalc(JSONObject locationJsonObject) throws JSONException {
RequestQueue queue = Volley.newRequestQueue(MainActivity.this);
String url = "https://maps.googleapis.com/maps/api/distancematrix/" +
"json?origins=" + locationJsonObject.getString("origin") + "&destinations=" + locationJsonObject.getString("destination") + "&mode=driving&" +
"language=en-EN&sensor=false" + "&key=" + /*Insert Your API Key Here */;
StringRequest stringRequest = new StringRequest(Request.Method.GET, url,
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
mTextView.setText("Response is: " + response.substring(0, 500));
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
mTextView.setText("That didn't work!");
}
});
queue.add(stringRequest);
}
【讨论】：
要获得两点之间的距离，请尝试此代码..
public static float GetDistanceFromCurrentPosition(double lat1,double lng1, double lat2, double lng2)
{
double earthRadius = 3958.75;
double dLat = Math.toRadians(lat2 - lat1);
double dLng = Math.toRadians(lng2 - lng1);
double a = Math.sin(dLat / 2) * Math.sin(dLat / 2)
+ Math.cos(Math.toRadians(lat1))
* Math.cos(Math.toRadians(lat2)) * Math.sin(dLng / 2)
* Math.sin(dLng / 2);
double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
double dist = earthRadius * c;
int meterConversion = 1609;
return new Float(dist * meterConversion).floatValue();
}
【讨论】：
您可以使用此功能。我在我的项目中使用过它。
public String getDistance(LatLng my_latlong, LatLng frnd_latlong) {
Location l1 = new Location("One");
l1.setLatitude(my_latlong.latitude);
l1.setLongitude(my_latlong.longitude);
Location l2 = new Location("Two");
l2.setLatitude(frnd_latlong.latitude);
l2.setLongitude(frnd_latlong.longitude);
float distance = l1.distanceTo(l2);
String dist = distance + " M";
if (distance > 1000.0f) {
distance = distance / 1000.0f;
dist = distance + " KM";
}
return dist;
}
【讨论】：
Location l2 = new Location("Two")
这是一个老问题，有老答案。我想强调一种计算两点之间距离的更新方法。现在我们应该熟悉实用程序类“SphericalUtil”。您可以使用它来检索距离。
double distance = SphericalUtil.computeDistanceBetween(origin, dest);
【讨论】：
在 android 谷歌地图应用程序中，有一种非常简单的方法可以找到 2 个位置之间的距离，请按照以下简单步骤进行操作：
当您第一次打开应用程序时，从下拉菜单中转到“您的时间线” 左上角的菜单。
打开新的windwo 后，从右上角菜单的设置中进行选择，然后选择“添加地点”。
祝你好运
【讨论】：