在Android上位置更改时持续更新标记
我正在尝试使用谷歌地图实现一个简单的导航应用程序。最初,我开发了一个代码,用于在地图上标记两个地理点,并显示它们之间的路线。 现在,我尝试根据用户位置将第一个标记移动到第二个标记(目的地) 为此,我使用了在Android上位置更改时持续更新标记,android,google-maps,google-maps-markers,Android,Google Maps,Google Maps Markers,我正在尝试使用谷歌地图实现一个简单的导航应用程序。最初,我开发了一个代码,用于在地图上标记两个地理点,并显示它们之间的路线。 现在,我尝试根据用户位置将第一个标记移动到第二个标记(目的地) 为此,我使用了LocationListener,并在onLocationChanged中实现了代码。 问题是onLocationChanged没有被触发,并且标记器没有根据用户位置移动。 这是我的密码 MapActivity.java public class MapActivity extends Frag
LocationListener
,并在onLocationChanged
中实现了代码。
问题是onLocationChanged
没有被触发,并且标记器没有根据用户位置移动。
这是我的密码
MapActivity.java
public class MapActivity extends FragmentActivity implements OnMapClickListener, LocationListener{
private GoogleMap gMap;
private ArrayList<LatLng> markersArray; //Marker points ArrayList
private ArrayList<Marker> markers;
private MarkerOptions options; //Marker options
String distance="";
String duration="";
private TextView travelDetails;
private ProgressDialog pDialog;
private double lattitude=0.0;
private double longitude=0.0;
Marker mMarker;
String bestAvailableProvider;
private LocationManager mLocationManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_map);
//Loading Google Maps
try{
loadMapView();
markersArray=new ArrayList<LatLng>();
markers=new ArrayList<Marker>();
gMap.setOnMapClickListener(this);
gMap.setMyLocationEnabled(true);
gMap.setMapType(GoogleMap.MAP_TYPE_SATELLITE);
travelDetails=(TextView) findViewById(R.id.lbl_traveldetails);
pDialog=new ProgressDialog(MapActivity.this);
}catch(Exception e){
e.printStackTrace();
}
}
/*
* This method loads map
*
*/
private void loadMapView(){
if (gMap==null) {
gMap=((SupportMapFragment)getSupportFragmentManager()
.findFragmentById(R.id.map_fragment)).getMap();
}
mLocationManager = (LocationManager) getApplicationContext().getSystemService(Context.LOCATION_SERVICE);
// Specify Location Provider criteria
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
criteria.setAltitudeRequired(false);
criteria.setBearingRequired(false);
criteria.setCostAllowed(true);
criteria.setSpeedRequired(false);
mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0,this);
}
/*
* catches onclick event of map
* @see com.google.android.gms.maps.GoogleMap.OnMapClickListener#onMapClick(com.google.android.gms.maps.model.LatLng)
*/
@Override
public void onMapClick(LatLng point) {
//Clearing markers in map
if (markersArray.size()>1) {
markersArray.clear();
gMap.clear();
}
//Adding marker to array
markersArray.add(point);
//marking point on Map
addMarkerOnMap(point);
//Drawing route when two markers are placed
if(markersArray.size() >= 2){
LatLng origin = markersArray.get(0);
LatLng dest = markersArray.get(1);
String url = getDirectionsUrl(origin, dest);
DownloadTask downloadTask = new DownloadTask();
downloadTask.execute(url);
}
}
/*
* This method places markers on map
*/
private void addMarkerOnMap(LatLng point){
//Marking points on map
options=new MarkerOptions();
options.position(point);
//Setting marker icons
if (markersArray.size()==1) {
//Source marker point
options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN));
}else if(markersArray.size()==2){
//Destination marker point
options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
}
//adding marker point to map
try{
Marker mMarker=gMap.addMarker(options);
markers.add(mMarker);
}catch(Exception e){
e.printStackTrace();
}
}
/*
* Getting direction url between two points
*
*/
private String getDirectionsUrl(LatLng origin,LatLng dest){
// Origin of route
String str_origin = "origin="+origin.latitude+","+origin.longitude;
// Destination of route
String str_dest = "destination="+dest.latitude+","+dest.longitude;
// Sensor enabled
String sensor = "sensor=false";
// Building the parameters to the web service
String parameters = str_origin+"&"+str_dest+"&"+sensor;
// Output format
String output = "json";
String url = "https://maps.googleapis.com/maps/api/directions/"+output+"?"+parameters;
return url;
}
/*
* passing the direction url
*
*/
private class DownloadTask extends AsyncTask<String, Void, String>{
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog.show();
pDialog.setMessage("Loading route...");
pDialog.setCancelable(false);
}
// Downloading data in non-ui thread
@Override
protected String doInBackground(String... url) {
// For storing data from web service
String data = "";
try{
// Fetching the data from web service
data = downloadUrl(url[0]);
}catch(Exception e){
Log.d("Background Task",e.toString());
}
return data;
}
// Executes in UI thread, after the execution of
// doInBackground()
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
ParserTask parserTask = new ParserTask();
// Invokes the thread for parsing the JSON data
parserTask.execute(result);
}
}
/*
* downloading from url
*
*/
private String downloadUrl(String strUrl) throws IOException{
String data = "";
InputStream iStream = null;
HttpURLConnection urlConnection = null;
try{
URL url = new URL(strUrl);
urlConnection = (HttpURLConnection) url.openConnection();
// Connecting to url
urlConnection.connect();
// Reading data from url
iStream = urlConnection.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(iStream));
StringBuffer sb = new StringBuffer();
String line = "";
while( ( line = br.readLine()) != null){
sb.append(line);
}
data = sb.toString();
br.close();
}catch(Exception e){
Log.d("Exception while downloading url", e.toString());
}finally{
iStream.close();
urlConnection.disconnect();
}
return data;
}
private class ParserTask extends AsyncTask<String, Integer, List<List<HashMap<String,String>>>>{
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected List<List<HashMap<String, String>>> doInBackground(String... jsonData) {
JSONObject jObject;
List<List<HashMap<String, String>>> routes = null;
try{
jObject = new JSONObject(jsonData[0]);
DirectionsJsonParser parser = new DirectionsJsonParser();
// Starts parsing data
routes = parser.parse(jObject);
}catch(Exception e){
e.printStackTrace();
}
return routes;
}
@Override
protected void onPostExecute(List<List<HashMap<String, String>>> result) {
ArrayList<LatLng> points = null;
PolylineOptions lineOptions = null;
// MarkerOptions markerOptions = new MarkerOptions();
// Traversing through all the routes
for(int i=0;i<result.size();i++){
points = new ArrayList<LatLng>();
lineOptions = new PolylineOptions();
// Fetching i-th route
List<HashMap<String, String>> path = result.get(i);
// Fetching all the points in i-th route
for(int j=0;j<path.size();j++){
HashMap<String,String> point = path.get(j);
if(j==0){ // Get distance from the list
distance = (String)point.get("distance");
continue;
}else if(j==1){ // Get duration from the list
duration = (String)point.get("duration");
continue;
}
double lat = Double.parseDouble(point.get("lat"));
double lng = Double.parseDouble(point.get("lng"));
LatLng position = new LatLng(lat, lng);
points.add(position);
}
// Adding all the points in the route to LineOptions
lineOptions.addAll(points);
lineOptions.width(5);
lineOptions.color(Color.BLUE);
}
// Drawing polyline in the Google Map for the i-th route
try{
gMap.addPolyline(lineOptions);
travelDetails.setText("Distance:"+distance+"Duration:"+duration);
pDialog.dismiss();
}catch (Exception e) {
if (pDialog.isShowing()) {
pDialog.dismiss();
}
Toast.makeText(getApplicationContext(), "No Road route found.", Toast.LENGTH_SHORT).show();
e.printStackTrace();
}
}
}
@Override
protected void onResume() {
super.onResume();
loadMapView();
}
@Override
protected void onPause() {
super.onPause();
mLocationManager.removeUpdates(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.map, menu);
return true;
}
/*
* (non-Javadoc)
* @see com.google.android.gms.maps.LocationSource.OnLocationChangedListener#onLocationChanged(android.location.Location)
*/
@Override
public void onLocationChanged(Location location) {
Log.e("loca", ""+location.getLatitude());
try {
if(markersArray.size()>0){
lattitude=location.getLatitude();
longitude=location.getLongitude();
LatLng mLatLng=new LatLng(lattitude, longitude);
Marker newMarker=markers.get(0);
newMarker.setPosition(mLatLng);
gMap.animateCamera(CameraUpdateFactory.newLatLng(mLatLng));
}
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
}
public class DirectionsJsonParser {
public List<List<HashMap<String,String>>> parse(JSONObject jObject){
List<List<HashMap<String, String>>> routes = new ArrayList<List<HashMap<String,String>>>() ;
JSONArray jRoutes = null;
JSONArray jLegs = null;
JSONArray jSteps = null;
JSONObject jDistance = null;
JSONObject jDuration = null;
try {
jRoutes = jObject.getJSONArray("routes");
for(int i=0;i<jRoutes.length();i++){
jLegs = ( (JSONObject)jRoutes.get(i)).getJSONArray("legs");
List path = new ArrayList<HashMap<String, String>>();
for(int j=0;j<jLegs.length();j++){
jSteps = ( (JSONObject)jLegs.get(j)).getJSONArray("steps");
/** Getting distance from the json data */
jDistance = ((JSONObject) jLegs.get(j)).getJSONObject("distance");
HashMap<String, String> hmDistance = new HashMap<String, String>();
hmDistance.put("distance", jDistance.getString("text"));
/** Getting duration from the json data */
jDuration = ((JSONObject) jLegs.get(j)).getJSONObject("duration");
HashMap<String, String> hmDuration = new HashMap<String, String>();
hmDuration.put("duration", jDuration.getString("text"));
/** Adding distance object to the path */
path.add(hmDistance);
/** Adding duration object to the path */
path.add(hmDuration);
/** Getting poly points */
for(int k=0;k<jSteps.length();k++){
String polyline = "";
polyline = (String)((JSONObject)((JSONObject)jSteps.get(k)).get("polyline")).get("points");
List<LatLng> list = decodePoly(polyline);
for(int l=0;l<list.size();l++){
HashMap<String, String> hm = new HashMap<String, String>();
hm.put("lat", Double.toString(((LatLng)list.get(l)).latitude) );
hm.put("lng", Double.toString(((LatLng)list.get(l)).longitude) );
path.add(hm);
}
}
/** Adding poly points */
routes.add(path);
}
}
} catch (JSONException e) {
e.printStackTrace();
}catch (Exception e){
}
return routes;
}
private List<LatLng> decodePoly(String encoded) {
List<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 p = new LatLng((((double) lat / 1E5)),
(((double) lng / 1E5)));
poly.add(p);
}
return poly;
}
}
公共类MapActivity扩展了FragmentActivity在MapClickListener、LocationListener上的实现{
私有谷歌地图;
私有ArrayList markersArray;//标记点ArrayList
私有数组列表标记;
私有标记选项;//标记选项
字符串距离=”;
字符串持续时间=”;
私人文本视图travelDetails;
私人对话;
私有双格度=0.0;
私人双经度=0.0;
标记器;
字符串最佳可用提供程序;
私人场所经理;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_map);
//加载谷歌地图
试一试{
loadMapView();
markersArray=newarraylist();
markers=newarraylist();
gMap.setOnMapClickListener(此);
gMap.setMyLocationEnabled(真);
gMap.setMapType(GoogleMap.MAP_-TYPE_卫星);
travelDetails=(TextView)findViewById(R.id.lbl\u travelDetails);
pDialog=newprogressdialog(MapActivity.this);
}捕获(例外e){
e、 printStackTrace();
}
}
/*
*此方法加载地图
*
*/
私有void loadMapView(){
如果(gMap==null){
gMap=((SupportMapFragment)getSupportFragmentManager()
.findFragmentById(R.id.map_片段)).getMap();
}
mLocationManager=(LocationManager)getApplicationContext().getSystemService(Context.LOCATION\u服务);
//指定位置提供程序条件
标准=新标准();
标准.设定准确度(标准.准确度/精细度);
标准。setAltitudeRequired(false);
标准。需要设置(假);
条件.setCostAllowed(true);
标准。设置所需速度(假);
mlLocationManager.RequestLocationUpdate(LocationManager.GPS_提供程序,0,0,此);
}
/*
*捕获地图的onclick事件
*@see com.google.android.gms.maps.GoogleMap.onmaclicklistener#onmaclick(com.google.android.gms.maps.model.LatLng)
*/
@凌驾
公共空区(停车点){
//清除地图上的标记
if(markersArray.size()>1){
markersArray.clear();
gMap.clear();
}
//向数组添加标记
markersArray.add(点);
//地图上的标记点
addMarkerOnMap(点);
//放置两个标记时绘制路线
if(markersArray.size()>=2){
LatLng origin=markersArray.get(0);
LatLng dest=markersArray.get(1);
字符串url=getDirectionsUrl(源、目标);
DownloadTask DownloadTask=新的DownloadTask();
downloadTask.execute(url);
}
}
/*
*此方法在地图上放置标记
*/
专用void addMarkerOnMap(LatLng点){
//在地图上标记点
选项=新标记选项();
选项。位置(点);
//设置标记图标
if(markersArray.size()==1){
//源标记点
图标(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN));
}else if(markersArray.size()==2){
//目的地标记点
图标(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
}
//向地图添加标记点
试一试{
Marker mMarker=gMap.addMarker(选项);
标记。添加(mMarker);
}捕获(例外e){
e、 printStackTrace();
}
}
/*
*获取两点之间的方向url
*
*/
私有字符串getDirectionsUrl(LatLng来源,LatLng目的地){
//路线起点
字符串str_origin=“origin=“+origin.latitude+”,“+origin.longitude;
//路线目的地
字符串str_dest=“destination=”+dest.latitude+”,“+dest.longitude;
//传感器启用
字符串sensor=“sensor=false”;
//为web服务构建参数
字符串参数=str_origin+“&”+str_dest+“&”+传感器;
//输出格式
字符串输出=“json”;
字符串url=”https://maps.googleapis.com/maps/api/directions/“+输出+”?“+参数;
返回url;
}
/*
*传递方向url
*
*/
私有类DownloadTask扩展了AsyncTask{
@凌驾
受保护的void onPreExecute(){
super.onPreExecute();
pDialog.show();
pDialog.setMessage(“装载路线…”);
pDialog.setCancelable(假);
}
//在非ui线程中下载数据
@凌驾
受保护的字符串doInBackground(字符串…url){
//用于存储来自web服务的数据
字符串数据=”;
试一试{
//从web服务获取数据
数据=下载url(url[0]);
}捕获(例外e){
Log.d(“后台任务”,例如toString());
}
返回数据;
}
//在UI线程中执行,在
//doInBackground()
@凌驾
受保护的void onPostExecute(字符串结果){
super.onPostExecute(结果);
ParserTask ParserTask=新的ParserTask();
//调用线程以解析JSON数据
执行(结果);
}
}
/*
*从url下载
*
*/
私有字符串下载URL(字符串strUrl)引发IOException{
字符串数据=”;
InputStream iStream=null;
HttpURLConnection-urlConnection=null;
试一试{
URL=新URL(strUrl);
urlConnection=(HttpURLConnection)url.openConnection();
//连接到url
urlConnection.connect();
//从url读取数据
iStream=urlConnection.getInputS