java - 地方上缺少标记

Question

这个问题已经有答案了:

Why do the markers not appear? (2 个回答)

已关闭 5 年前。

我拥有的是:一个包含餐厅、酒吧等图像的 RecyclerView，单击这些图像即可转到 map

我想要的:当点击它们时，您会看到一张带有标记的 map ，其中标记有您周围的所述地点

我的问题:我在另一个应用程序中执行此操作，但另一个应用程序直接向您显示带有当前位置的 map ，当您单击按钮时显示我想要的信息。但我尝试在这个应用程序上执行此操作，在方法上添加请求，但标记没有显示，标记被添加到名为 GetNearbyPlacesData 的类上。

我的问题:为什么标记不显示？如果解释带有代码示例，我将非常感激，提前致谢

我过去如何执行我的请求

      public class MapsActivity extends FragmentActivity implements OnMapReadyCallback,
        GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener,
        LocationListener {

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);

        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            checkLocationPermission();
        }

        //Check if Google Play Services Available or not
        if (!CheckGooglePlayServices()) {
            Log.d("onCreate", "Finishing test case since Google Play Services are not available");
            finish();
        }
        else {
            Log.d("onCreate","Google Play Services available.");
        }

        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);
    }

 @Override
    public void onMapReady(GoogleMap googleMap) {//esta funcion es llamada cuando el mapa esta listo para usarse(1- locacion)
        mMap = googleMap;
        mMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);//esto es lo que que dice de que forma queremos que se vea el mapa

        //Initialize Google Play Services
        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (ContextCompat.checkSelfPermission(this,
                    Manifest.permission.ACCESS_FINE_LOCATION)
                    == PackageManager.PERMISSION_GRANTED) {
                buildGoogleApiClient();
                mMap.setMyLocationEnabled(true);
            }
        }
        else {
            buildGoogleApiClient();
            mMap.setMyLocationEnabled(true);
        }
  //REQUEST TRIGGERED BY BUTTON
            Button btnRestaurant = (Button) findViewById(R.id.btnRestaurant);//asi se hace la peticion
            btnRestaurant.setOnClickListener(new View.OnClickListener() {
                String Restaurant = "restaurant";
                @Override
                public void onClick(View v) {
                    Log.d("onClick", "Button is Clicked");
                    mMap.clear();
                    String url = getUrl(latitude, longitude, Restaurant);
                    Object[] DataTransfer = new Object[2];
                    DataTransfer[0] = mMap;
                    DataTransfer[1] = url;
                    Log.d("onClick", url);
                    GetNearbyPlacesData getNearbyPlacesData = new GetNearbyPlacesData();
                    getNearbyPlacesData.execute(DataTransfer);
                    Toast.makeText(MapsActivity.this,"Nearby Restaurants", Toast.LENGTH_LONG).show();
                }
            });

我如何执行我的请求

 public class MapsActivity extends FragmentActivity implements OnMapReadyCallback,
        GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener,
        LocationListener {

private static final String EXTRA_TRIGGER_METHOD = "trigger_method";

    public static Intent getIntent(Context context, boolean triggerMethod) {
        Intent intent = new Intent(context, MapsActivity.class);
        intent.putExtra(EXTRA_TRIGGER_METHOD, triggerMethod);
        return intent;
    }

    private boolean triggerMethod;
@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);

        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            checkLocationPermission();
        }

        //Check if Google Play Services Available or not
        if (!CheckGooglePlayServices()) {
            Log.d("onCreate", "Finishing test case since Google Play Services are not available");
            finish();
        }
        else {
            Log.d("onCreate","Google Play Services available.");
        }

        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);

        triggerMethod = getIntent().getBooleanExtra(EXTRA_TRIGGER_METHOD, false);

        if (triggerMethod) {
            Method();
        }
    }
 //REQUEST TRIGGERED BY METHOD    
    public void Method(){
            String Restaurant = "restaurant";
                    //mMap.clear();
                    String url = getUrl(latitude, longitude, Restaurant);
                    Object[] DataTransfer = new Object[2];
                    DataTransfer[0] = mMap;
                    DataTransfer[1] = url;
                    Log.d("onClick", url);
                    GetNearbyPlacesData getNearbyPlacesData = new GetNearbyPlacesData();
                    getNearbyPlacesData.execute(DataTransfer);
                    Toast.makeText(MapsActivity.this,"Nearby Restaurants", Toast.LENGTH_LONG).show();
        }
The class where I add the markers

    public class GetNearbyPlacesData extends AsyncTask<Object, String, String> {

    String googlePlacesData;
    GoogleMap mMap;
    String url;

    @Override
    protected String doInBackground(Object... params) {
        try {
            Log.d("GetNearbyPlacesData", "doInBackground entered");
            mMap = (GoogleMap) params[0];
            url = (String) params[1];
            DownloadUrl downloadUrl = new DownloadUrl();
            googlePlacesData = downloadUrl.readUrl(url);
            Log.d("GooglePlacesReadTask", "doInBackground Exit");
        } catch (Exception e) {
            Log.d("GooglePlacesReadTask", e.toString());
        }
        return googlePlacesData;
    }

    @Override
    protected void onPostExecute(String result) {
        Log.d("GooglePlacesReadTask", "onPostExecute Entered");
        List<HashMap<String, String>> nearbyPlacesList = null;
        DataParser dataParser = new DataParser();
        nearbyPlacesList =  dataParser.parse(result);
        ShowNearbyPlaces(nearbyPlacesList);
        Log.d("GooglePlacesReadTask", "onPostExecute Exit");
    }

    private void ShowNearbyPlaces(List<HashMap<String, String>> nearbyPlacesList) {
        for (int i = 0; i < nearbyPlacesList.size(); i++) {
            Log.d("onPostExecute","Entered into showing locations");
            MarkerOptions markerOptions = new MarkerOptions();
            HashMap<String, String> googlePlace = nearbyPlacesList.get(i);
            double lat = Double.parseDouble(googlePlace.get("lat"));
            double lng = Double.parseDouble(googlePlace.get("lng"));
            String placeName = googlePlace.get("place_name");
            String vicinity = googlePlace.get("vicinity");
            LatLng latLng = new LatLng(lat, lng);
            MarkerOptions options = new MarkerOptions();
            //options.position(LatLng);options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
            options.title("Restaurante");
            options.snippet("Burger King");
            mMap.addMarker(options);
            markerOptions.position(latLng);
            markerOptions.title(placeName + " : " + vicinity);
            mMap.addMarker(markerOptions);//esto añade los marcadores
            markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));//aqui se le pone el color a los marcadores
            //move map camera
            mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
            mMap.animateCamera(CameraUpdateFactory.zoomTo(15));
        }
    }
}

我添加标记的类

    public class GetNearbyPlacesData extends AsyncTask<Object, String, String> {

    String googlePlacesData;
    GoogleMap mMap;
    String url;

    @Override
    protected String doInBackground(Object... params) {
        try {
            Log.d("GetNearbyPlacesData", "doInBackground entered");
            mMap = (GoogleMap) params[0];
            url = (String) params[1];
            DownloadUrl downloadUrl = new DownloadUrl();
            googlePlacesData = downloadUrl.readUrl(url);
            Log.d("GooglePlacesReadTask", "doInBackground Exit");
        } catch (Exception e) {
            Log.d("GooglePlacesReadTask", e.toString());
        }
        return googlePlacesData;
    }

    @Override
    protected void onPostExecute(String result) {
        Log.d("GooglePlacesReadTask", "onPostExecute Entered");
        List<HashMap<String, String>> nearbyPlacesList = null;
        DataParser dataParser = new DataParser();
        nearbyPlacesList =  dataParser.parse(result);
        ShowNearbyPlaces(nearbyPlacesList);
        Log.d("GooglePlacesReadTask", "onPostExecute Exit");
    }

    private void ShowNearbyPlaces(List<HashMap<String, String>> nearbyPlacesList) {
        for (int i = 0; i < nearbyPlacesList.size(); i++) {
            Log.d("onPostExecute","Entered into showing locations");
            MarkerOptions markerOptions = new MarkerOptions();
            HashMap<String, String> googlePlace = nearbyPlacesList.get(i);
            double lat = Double.parseDouble(googlePlace.get("lat"));
            double lng = Double.parseDouble(googlePlace.get("lng"));
            String placeName = googlePlace.get("place_name");
            String vicinity = googlePlace.get("vicinity");
            LatLng latLng = new LatLng(lat, lng);
            MarkerOptions options = new MarkerOptions();
            //options.position(LatLng);options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
            options.title("Restaurante");
            options.snippet("Burger King");
            mMap.addMarker(options);
            markerOptions.position(latLng);
            markerOptions.title(placeName + " : " + vicinity);
            mMap.addMarker(markerOptions);//esto añade los marcadores
            markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));//aqui se le pone el color a los marcadores
            //move map camera
            mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
            mMap.animateCamera(CameraUpdateFactory.zoomTo(15));
        }
    }
}

Answer 1

在 postexecute 方法中创建一个处理程序，如下所示

 Handler handler = new Handler();
            handler.post(new Runnable() {
                @Override
                public void run() {
                    ShowNearbyPlaces(nearbyPlacesList);
                }
            });