我正在制作一个应用程序来显示最近的五个地铁站。我能够获取工作站的名称，并用数据填充列表视图。
我正在从API获取lng＆amp; lat，并希望使用这些坐标将地图添加到地图中。我有地图工作，我能够显示一个引脚，但不能显示多个引脚。我们非常感谢正确方向的一点 - 请参阅下面的代码。
public class nearMe extends AppCompatActivity implements OnMapReadyCallback {
private MapView mapView;
public GoogleMap gmap;
private static final String MAP_VIEW_BUNDLE_KEY = "MapViewBundleKey";
// Location Co-ordinates
private String lat = "";
private String lng = "";
LocationManager locationManager;
LocationListener locationListener;
private List<Station> stationList = new ArrayList<>();
private RecyclerView recyclerView;
private stationAdapter mAdapter;
/* LOCATION STUFF */
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
startListening();
}
}
public void startListening() {
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
}
}
public void updateLocationInfo(Location location) {
lat = "" + location.getLatitude();
lng = "" + location.getLongitude();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_location, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// int id = item.getItemId();
getNearestStations();
Toast.makeText(this, "Location Updated!", Toast.LENGTH_SHORT).show();
return super.onOptionsItemSelected(item);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_near_me);
recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
mAdapter = new stationAdapter(stationList);
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
recyclerView.setLayoutManager(mLayoutManager);
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setAdapter(mAdapter);
// onClick
recyclerView.addOnItemTouchListener(new TouchListener(getApplicationContext(), recyclerView, new ClickListener() {
@Override
public void onClick(View view, int position) {
// Toast.makeText(getApplicationContext(), stationList.get(position).getStation() + "", Toast.LENGTH_SHORT).show();
String findStation = stationList.get(position).getStation();
// Toast.makeText(nearMe.this, bob, Toast.LENGTH_SHORT).show();
Uri gmmIntentUri = Uri.parse("google.navigation:q="+findStation+"underground station+London&mode=w");
Intent mapIntent = new Intent(Intent.ACTION_VIEW, gmmIntentUri);
mapIntent.setPackage("com.google.android.apps.maps");
mapIntent.setFlags(mapIntent.FLAG_ACTIVITY_CLEAR_TOP);
if (mapIntent.resolveActivity(getPackageManager()) != null) {
startActivity(mapIntent);
}
}
}));
locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
locationListener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
updateLocationInfo(location);
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
};
if (Build.VERSION.SDK_INT < 23) {
startListening();
} else {
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1);
} else {
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
updateLocationInfo(location);
}
}
}
// insert Stations in to recycler
getNearestStations();
//map
Bundle mapViewBundle = null;
if (savedInstanceState != null) {
mapViewBundle = savedInstanceState.getBundle(MAP_VIEW_BUNDLE_KEY);
}
mapView = (MapView) findViewById(R.id.map_view);
mapView.onCreate(mapViewBundle);
mapView.getMapAsync(this);
}
// clear adapter before adding
public void clear() {
int size = this.stationList.size();
this.stationList.clear();
mAdapter.notifyItemRangeRemoved(0, size);
}
public void getNearestStations(){
RequestQueue queue = Volley.newRequestQueue(this);
String url = "https://transportapi.com/v3/uk/tube/stations/near.json?app_id=157c4895&app_key=091697cea8bae89519dd02ebb318fc51&lat=" + lat + "&lon=" + lng + "&rpp=5";
final StringRequest stringRequest = new StringRequest(url, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
try {
JSONObject jsonObject = new JSONObject(response);
JSONArray jsonArray = jsonObject.getJSONArray("stations");
// Call 'Clear' method to clear mAdapter before adding new data
clear();
if (jsonArray.length() > 0) {
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jObject = jsonArray.getJSONObject(i);
String station = jObject.getString("name");
Station newStation = new Station(station);
stationList.add(newStation);
mAdapter.notifyDataSetChanged();
double longitude = Double.parseDouble(lng);
double latitude = Double.parseDouble(lat);
gmap.addMarker(new MarkerOptions()
.position(new LatLng(latitude, longitude))
.title(station));
}
}else{
Station newStation = new Station("No stations near");
stationList.add(newStation);
mAdapter.notifyDataSetChanged();
// Show a diaog
AlertDialog alertDialog = new AlertDialog.Builder(nearMe.this).create();
alertDialog.setTitle("No Stations Found");
alertDialog.setMessage("You are either not in London or you have no network connectivity.");
alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
}); alertDialog.show();
}
} catch (JSONException e) { }
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
});
RequestQueue requestQueue = Volley.newRequestQueue(getApplicationContext());
requestQueue.add(stringRequest);
}
// maps
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
Bundle mapViewBundle = outState.getBundle(MAP_VIEW_BUNDLE_KEY);
if (mapViewBundle == null) {
mapViewBundle = new Bundle();
outState.putBundle(MAP_VIEW_BUNDLE_KEY, mapViewBundle);
}
mapView.onSaveInstanceState(mapViewBundle);
}
@Override
protected void onResume() {
super.onResume();
mapView.onResume();
}
@Override
protected void onStart() {
super.onStart();
mapView.onStart();
}
@Override
protected void onStop() {
super.onStop();
mapView.onStop();
}
@Override
protected void onPause() {
mapView.onPause();
super.onPause();
}
@Override
protected void onDestroy() {
mapView.onDestroy();
super.onDestroy();
}
@Override
public void onLowMemory() {
super.onLowMemory();
mapView.onLowMemory();
}
@Override
public void onMapReady(GoogleMap googleMap) {
}
}
答案 0 :(得分：1)
假设您的API返回markers数组中的数据。
for(int i = 0 ; i < markers.size() ; i++ ) {
createMarker(markers.get(i).getLatitude(), markers.get(i).getLongitude(), markers.get(i).getTitle(), markers.get(i).getSnippet(), markers.get(i).getIconResID());
}
...
protected Marker createMarker(double latitude, double longitude, String title, String snippet, int iconResID) {
return googleMap.addMarker(new MarkerOptions()
.position(new LatLng(latitude, longitude))
.anchor(0.5f, 0.5f)
.title(title)
.snippet(snippet);
.icon(BitmapDescriptorFactory.fromResource(iconResID)));
}