Android 无法使用google地图获取地图
我没有得到谷歌地图使用谷歌地方API和谷歌地图API V2。 我正在显示我正在使用的所有代码，因为无法解决错误 我想用GooglePlacesAPI和GoogleMapAndroidAPIv2显示附近的地方 我在这行中遇到错误：Android 无法使用google地图获取地图,android,google-maps,google-places-api,Android,Google Maps,Google Places Api,我没有得到谷歌地图使用谷歌地方API和谷歌地图API V2。 我正在显示我正在使用的所有代码，因为无法解决错误 我想用GooglePlacesAPI和GoogleMapAndroidAPIv2显示附近的地方 我在这行中遇到错误： // Getting Google Map mGoogleMap = fragment.getMap(); 错误是无法解析getMap（） MainActivity.java public class MainActivity extends FragmentAc
// Getting Google Map
mGoogleMap = fragment.getMap();
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.getMapAsync(this);
// onMapReady(GoogleMap 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);
}
}
}
<fragment
android:id="@+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent" />
mapFragment.getMapAsync(this);
要添加到我的评论中，您可能需要使用
getmapsync（）getMap（）根据我使用此API的经验，我相信此方法已被替换为。您还需要实现请参见代码。我编辑过。我应该在哪里更改以解决此问题？我不明白你这是什么意思？你确定这样行吗？我在Android Studio中为
getMap（）。其次，将mGoogleMap=fragment.getMap（）
替换为fragment.getmapsync（this）
。第三，将对mGoogleMap
的所有调用从onCreate（）
移动到onMapReady（GoogleMap-GoogleMap）
。我必须在代码中编辑OnMapReadyCallback？您能准确地告诉我吗？@user6313669在类的顶部，就在实现LocationListener
之后添加一个逗号和OnMapReadyCallback
，因此您的完整类声明是public class MainActivity extends FragmentActivity implements LocationListener，OnMapReadyCallback
。IDE将给您一个警告，说明尚未实现方法，可能在类声明下面有一条红线。若要删除此错误，请将方法@Override public void onMapReady（GoogleMap GoogleMap）
添加到您的类中。我已根据您的建议进行了更改，现在我收到了我提到的NPE错误，并编辑了更改的代码。请看，请看代码。我编辑过。我应该在哪里更改以解决此问题？我不明白。@user6313669请参阅“注释”部分中的PPartisan解释，这是正确的方法
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)
<fragment
android:id="@+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent" />
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) {
}
});
}
}
mapFragment.getMapAsync(this);
public class MyMapActivity extends AppCompatActivity implements OnMapReadyCallback {
private GoogleMap mMap;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
mMap.getUiSettings().setMapToolbarEnabled(false);
//etc...
}
}