android - 无法使用谷歌地图获取 map

Question

我没有使用 Google Places API 和 Google Map API V2 获取谷歌地图。我正在显示我正在使用的所有代码，因为无法解决错误。

我想使用 Google Places API 和 Google Map Android API V2 显示附近的地点。

我在这一行中遇到错误:

// Getting Google Map
  mGoogleMap = fragment.getMap();

错误是无法解析getMap();

Note: C:\Users\techaboard user\Downloads\LocationNearby9\app\src\main\java\neerajshah\locationnearby\MainActivity.java uses or overrides a deprecated API.
Error:(106, 34) error: cannot find symbol method getMap()

主 Activity .java

public class MainActivity extends FragmentActivity implements LocationListener,OnMapReadyCallback {

    GoogleMap mGoogleMap;
     Spinner mSprPlaceType;

    String[] mPlaceType = null;
    String[] mPlaceTypeName = null;

    double mLatitude = 0;
    double mLongitude = 0;
    /**
     * ATTENTION: This was auto-generated to implement the App Indexing API.
     * See https://g.co/AppIndexing/AndroidStudio for more information.
     */
    private GoogleApiClient client;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Array of place types
        mPlaceType = getResources().getStringArray(R.array.place_type);

        // Array of place type names
        mPlaceTypeName = getResources().getStringArray(R.array.place_type_name);

        // Creating an array adapter with an array of Place types
        // to populate the spinner
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item, mPlaceTypeName);

        // Getting reference to the Spinner
        mSprPlaceType = (Spinner) findViewById(R.id.spr_place_type);

        // Setting adapter on Spinner to set place types
        mSprPlaceType.setAdapter(adapter);

        Button btnFind;

        // Getting reference to Find Button
        btnFind = (Button) findViewById(R.id.btn_find);

        // Getting Google Play availability status
        int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getBaseContext());

        if (status != ConnectionResult.SUCCESS) { // Google Play Services are not available

            int requestCode = 10;
            Dialog dialog = GooglePlayServicesUtil.getErrorDialog(status, this, requestCode);
            dialog.show();

        } else { // Google Play Services are available

            // Getting reference to the SupportMapFragment


           SupportMapFragment fragment = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map));

            // Getting Google Map
//setUpMapIfNeeded();
            fragment.getMapAsyn‌​c(this);
           // onMapReady(GoogleMa‌​p googleMap);
            //mGoogleMap = fragment.getMap();
            // Enabling MyLocation in Google Map
            mGoogleMap.setMyLocationEnabled(true);

            // Getting LocationManager object from System Service LOCATION_SERVICE
            LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);

            // Creating a criteria object to retrieve provider
            Criteria criteria = new Criteria();

            // Getting the name of the best provider
            String provider = locationManager.getBestProvider(criteria, true);

            // Getting Current Location From GPS
            if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                // TODO: Consider calling
                //    ActivityCompat#requestPermissions
                // here to request the missing permissions, and then overriding
                //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
                //                                          int[] grantResults)
                // to handle the case where the user grants the permission. See the documentation
                // for ActivityCompat#requestPermissions for more details.
                return;
            }
            Location location = locationManager.getLastKnownLocation(provider);

            if (location != null) {
                onLocationChanged(location);
            }

            locationManager.requestLocationUpdates(provider, 20000, 0, this);

            // Setting click event lister for the find button
            btnFind.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {

                    int selectedPosition = mSprPlaceType.getSelectedItemPosition();
                    String type = mPlaceType[selectedPosition];

                    StringBuilder sb = new StringBuilder("https://maps.googleapis.com/maps/api/place/nearbysearch/json?");
                    sb.append("location=" + mLatitude + "," + mLongitude);
                    sb.append("&radius=5000");
                    sb.append("&types=" + type);
                    sb.append("&sensor=true");
                    sb.append("&key=AIzaSyCl0SmU1xPrcR_f_VG-PoGWpDYY9qagTcE");

                    // Creating a new non-ui thread task to download json data
                    PlacesTask placesTask = new PlacesTask();

                    // Invokes the "doInBackground()" method of the class PlaceTask
                    placesTask.execute(sb.toString());

                }
            });

        }

        // ATTENTION: This was auto-generated to implement the App Indexing API.
        // See https://g.co/AppIndexing/AndroidStudio for more information.
        client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();
    }
        /**
     * A method to download json data from url
     */
    private String downloadUrl(String strUrl) throws IOException {
        String data = "";
        InputStream iStream = null;
        HttpURLConnection urlConnection = null;
        try {
            URL url = new URL(strUrl);

            // Creating an http connection to communicate with url
            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;
    }



    @Override
    public void onStart() {
        super.onStart();

        // ATTENTION: This was auto-generated to implement the App Indexing API.
        // See https://g.co/AppIndexing/AndroidStudio for more information.
        client.connect();
        Action viewAction = Action.newAction(
                Action.TYPE_VIEW, // TODO: choose an action type.
                "Main Page", // TODO: Define a title for the content shown.
                // TODO: If you have web page content that matches this app activity's content,
                // make sure this auto-generated web page URL is correct.
                // Otherwise, set the URL to null.
                Uri.parse("http://host/path"),
                // TODO: Make sure this auto-generated app URL is correct.
                Uri.parse("android-app://neerajshah.locationnearby/http/host/path")
        );
        AppIndex.AppIndexApi.start(client, viewAction);
    }

    @Override
    public void onStop() {
        super.onStop();

        // ATTENTION: This was auto-generated to implement the App Indexing API.
        // See https://g.co/AppIndexing/AndroidStudio for more information.
        Action viewAction = Action.newAction(
                Action.TYPE_VIEW, // TODO: choose an action type.
                "Main Page", // TODO: Define a title for the content shown.
                // TODO: If you have web page content that matches this app activity's content,
                // make sure this auto-generated web page URL is correct.
                // Otherwise, set the URL to null.
                Uri.parse("http://host/path"),
                // TODO: Make sure this auto-generated app URL is correct.
                Uri.parse("android-app://neerajshah.locationnearby/http/host/path")
        );
        AppIndex.AppIndexApi.end(client, viewAction);
        client.disconnect();
    }
    @Override
    public void onMapReady(GoogleMap googleMap) {
         GoogleMap map;
        map = googleMap;

        map.getUiSettings().setMapToolbarEnabled(false);
      //  map.getUiSettings().setMyLocationButtonEnabled(false);
        //map.getUiSettings().setZoomControlsEnabled(false);
        //etc...
    }

    @Override
    public void onLocationChanged(Location location) {
        mLatitude = location.getLatitude();
        mLongitude = location.getLongitude();
        LatLng latLng = new LatLng(mLatitude, mLongitude);

        mGoogleMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
        mGoogleMap.animateCamera(CameraUpdateFactory.zoomTo(12));

    }

    @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
    }
}


    /**
     * A class, to download Google Places
     */
    class PlacesTask extends AsyncTask<String, Integer, String> {

        String data = null;

        // Invoked by execute() method of this object
        @Override
        protected String doInBackground(String... url) {
            try {
         //       data = downloadUrl(url[0]);
            } catch (Exception e) {
                Log.d("Background Task", e.toString());
            }
            return data;
        }



        // Executed after the complete execution of doInBackground() method
        @Override
        protected void onPostExecute(String result) {
            ParserTask parserTask = new ParserTask();

            // Start parsing the Google places in JSON format
            // Invokes the "doInBackground()" method of the class ParseTask
            parserTask.execute(result);
        }


    }

    /**
     * A class to parse the Google Places in JSON format
     */
    class ParserTask extends AsyncTask<String, Integer, List<HashMap<String, String>>> {

        JSONObject jObject;

        // Invoked by execute() method of this object
        @Override
        protected List<HashMap<String, String>> doInBackground(String... jsonData) {

            List<HashMap<String, String>> places = null;
            PlaceJSONParser placeJsonParser = new PlaceJSONParser();

            try {
                jObject = new JSONObject(jsonData[0]);

                /** Getting the parsed data as a List construct */
                places = placeJsonParser.parse(jObject);

            } catch (Exception e) {
                Log.d("Exception", e.toString());
            }
            return places;
        }

        // Executed after the complete execution of doInBackground() method
        @Override
        protected void onPostExecute(List<HashMap<String, String>> list) {

            // Clears all the existing markers


            GoogleMap mGoogleMap =null;
            mGoogleMap.clear();

            for (int i = 0; i < list.size(); i++) {

                // Creating a marker
                MarkerOptions markerOptions = new MarkerOptions();

                // Getting a place from the places list
                HashMap<String, String> hmPlace = list.get(i);

                // Getting latitude of the place
                double lat = Double.parseDouble(hmPlace.get("lat"));

                // Getting longitude of the place
                double lng = Double.parseDouble(hmPlace.get("lng"));

                // Getting name
                String name = hmPlace.get("place_name");

                // Getting vicinity
                String vicinity = hmPlace.get("vicinity");

                LatLng latLng = new LatLng(lat, lng);

                // Setting the position for the marker
                markerOptions.position(latLng);

                // Setting the title for the marker.
                //This will be displayed on taping the marker
                markerOptions.title(name + " : " + vicinity);

                // Placing a marker on the touched position

                mGoogleMap.addMarker(markerOptions);
            }
        }
    }

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <Spinner
        android:id="@+id/spr_place_type"
        android:layout_width="wrap_content"
        android:layout_height="60dp"
        android:layout_alignParentTop="true" />

    <Button
        android:id="@+id/btn_find"
        android:layout_width="wrap_content"
        android:layout_height="60dp"
        android:layout_alignParentTop="true"
        android:layout_toRightOf="@id/spr_place_type"
        android:text="@string/str_btn_find" />



    <fragment xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/map"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/spr_place_type"
        class="com.google.android.gms.maps.SupportMapFragment" />

</RelativeLayout>

日志

   FATAL EXCEPTION: main
                                                                         Process: neerajshah.locationnearby, PID: 7764
                                                                         java.lang.RuntimeException: Unable to start activity ComponentInfo{neerajshah.locationnearby/neerajshah.locationnearby.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.google.android.gms.maps.GoogleMap.setMyLocationEnabled(boolean)' on a null object reference
                                                                             at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2426)
                                                                             at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490)
                                                                             at android.app.ActivityThread.access$900(ActivityThread.java:154)
                                                                             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354)
                                                                             at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                             at android.os.Looper.loop(Looper.java:148)
                                                                             at android.app.ActivityThread.main(ActivityThread.java:5443)
                                                                             at java.lang.reflect.Method.invoke(Native Method)
                                                                             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
                                                                             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
                                                                          Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.google.android.gms.maps.GoogleMap.setMyLocationEnabled(boolean)' on a null object reference
                                                                             at neerajshah.locationnearby.MainActivity.onCreate(MainActivity.java:111)
                                                                             at android.app.Activity.performCreate(Activity.java:6259)
                                                                             at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1130)
                                                                             at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2379)
                                                                             at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490) 
                                                                             at android.app.ActivityThread.access$900(ActivityThread.java:154) 
                                                                             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354) 
                                                                             at android.os.Handler.dispatchMessage(Handler.java:102) 
                                                                             at android.os.Looper.loop(Looper.java:148) 
                                                                             at android.app.ActivityThread.main(ActivityThread.java:5443) 

Answer 1

在 XML 中添加它。

 <fragment
                android:id="@+id/map"
                android:name="com.google.android.gms.maps.SupportMapFragment"
                android:layout_width="match_parent"
                android:layout_height="match_parent" />

并尝试在 Java 文件中使用它

private GoogleMap map;
private void setUpMapIfNeeded() {
    // Do a null check to confirm that we have not already instantiated the
    // map.
    if (map == null) {

        map = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();

        if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }
        map.setMyLocationEnabled(true);
        map.getUiSettings().setMyLocationButtonEnabled(false);
        map.getUiSettings().setZoomControlsEnabled(false);
        map.setOnMyLocationChangeListener(new GoogleMap.OnMyLocationChangeListener() {
            @Override
            public void onMyLocationChange(Location loc) {

            }
        });
    }

}