Question

所以在解决了我的问题Converting JSONObject to JSONArray后，我能够从JSON文件中获取Lat，Long。但是，我似乎无法让标记显示出来。

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

JSONParser jsonParser = new JSONParser();
private GoogleMap mMap;
private GoogleMap nMap;
private static final LatLng Tampines = new LatLng(1.3525,103.9446);
List<TaxiCoordinates> myCoordinates = new ArrayList<TaxiCoordinates>();
private ProgressDialog pDialog;
MapsActivity map;
private static final String apiURL = "http://datamall2.mytransport.sg/ltaodataservice/TaxiAvailability/";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_maps);
    // Obtain the SupportMapFragment and get notified when the map is ready to be used.
    MapFragment mapFragment = (MapFragment) getFragmentManager()
            .findFragmentById(R.id.map);
    mapFragment.getMapAsync(this);

    myCoordinates = new ArrayList<TaxiCoordinates>();
    new GetCoordinates().execute();

}

/**
 * Manipulates the map once available.
 * This callback is triggered when the map is ready to be used.
 * This is where we can add markers or lines, add listeners or move the camera. In this case,
 * we just add a marker near Sydney, Australia.
 * If Google Play services is not installed on the device, the user will be prompted to install
 * it inside the SupportMapFragment. This method will only be triggered once the user has
 * installed Google Play services and returned to the app.
 */
@Override
public void onMapReady(GoogleMap googleMap) {
    mMap = googleMap;
    mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(Tampines, 10));




    // Add a marker in Sydney and move the camera
    // LatLng sydney = new LatLng(-34, 151);
    // mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
    // mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
}

class GetCoordinates extends AsyncTask<String, String, JSONArray> {
    private ProgressDialog progressDialog;

    @Override
    protected JSONArray doInBackground(String... params)
    {
        try {
            JSONArray json = jsonParser.makeHttpRequest(
                    apiURL, "GET");

            if (json != null) {
                Log.d("JSON result", json.toString());

                return json;
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        progressDialog = new ProgressDialog(MapsActivity.this);
        progressDialog.setMessage("Loading Taxis...");
        progressDialog.show();
    }

    @Override
    protected void onPostExecute(JSONArray jsonArray) {

        if (jsonArray != null)
        {
            //loop
            for(int i = 0; i < jsonArray.length(); i++)
            {
                try
                {
                    JSONObject c = jsonArray.getJSONObject(i);
                    TaxiCoordinates temp = new TaxiCoordinates();
                    temp.setLatitude(c.getDouble("Latitude"));
                    temp.setLongitude(c.getDouble("Longitude"));
                    myCoordinates.add(temp);
                    if(progressDialog!=null && progressDialog.isShowing())
                    {
                        progressDialog.dismiss();
                    }

                }
                catch (JSONException e)
                {
                    e.printStackTrace();
                }
            }
            addMarkers();
        }
    }
}



public void addMarkers()
{
    for(TaxiCoordinates c: myCoordinates)
    {
        double tempLat = c.getLatitude();
        double tempLong = c.getLongitude();

        LatLng taxi = new LatLng(tempLat, tempLong);
        mMap.addMarker(new MarkerOptions()
                .position(taxi)
                .title("Available"));

        //MarkerOptions m =  new MarkerOptions().title("Available").position(new LatLng(tempLat, tempLong));
        //googleMap.addMarker(m);
    }
}
}

顺便说一句，我尝试将addMarkers()的代码放入正确的onMapReady()，但仍然没有显示。

编辑：我试过这个：

mMap.addMarker(new MarkerOptions().position(tempLat,tempLng).title(Available).snippet(details).icon(BitmapDescriptorFactory.fromResource(markericon))); //tried default ones too.

Answer 1

没关系，我是个傻瓜。这样做我错过了一部分。

mMap.addMarker(new MarkerOptions().position(tempLat,tempLng).title(Available).snippet(details).icon(    .fromResource(markericon))); //tried default ones too.

Google地图标记未显示（Android）

1 个答案: