如何在谷歌地图android中获取当前位置

Question

其实我的问题是我没有得到当前的位置纬度和经度我尝试了很多方法.我知道这个问题已经问过我试过那个答案还是我还没有得到答案.请帮助我代码:

    if (googleMap == null) {
        googleMap = ((MapFragment) getFragmentManager().findFragmentById(
                R.id.map)).getMap();

        // check if map is created successfully or not
        if (googleMap == null) {
            Toast.makeText(getApplicationContext(),
                    "Sorry! unable to create maps", Toast.LENGTH_SHORT)
                    .show();
        }
    }
    googleMap.setMyLocationEnabled(true);
    Location myLocation = googleMap.getMyLocation();  //Nullpointer exception.........
    LatLng myLatLng = new LatLng(myLocation.getLatitude(),
            myLocation.getLongitude());

    CameraPosition myPosition = new CameraPosition.Builder()
            .target(myLatLng).zoom(17).bearing(90).tilt(30).build();
    googleMap.animateCamera(
        CameraUpdateFactory.newCameraPosition(myPosition));

Answer 1

请查看Google Maps Android API v2的示例代码.使用它将解决您的问题.

private void setUpMapIfNeeded() {
    // Do a null check to confirm that we have not already instantiated the map.
    if (mMap == null) {
        // Try to obtain the map from the SupportMapFragment.
        mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
        mMap.setMyLocationEnabled(true);
        // Check if we were successful in obtaining the map.
        if (mMap != null) {
            mMap.setOnMyLocationChangeListener(new GoogleMap.OnMyLocationChangeListener() {
                @Override
                public void onMyLocationChange(Location arg0) {
                    mMap.addMarker(new MarkerOptions().position(new LatLng(arg0.getLatitude(), arg0.getLongitude())).title("It's Me!"));
                }
            });
        }
    }
}

在onCreate函数中调用此函数.

Answer 2

我认为现在更好的方法是:

Location currentLocation = LocationServices.FusedLocationApi.getLastLocation(googleApiClient);

文档.获取最后的位置

Answer 3

package com.example.sandeep.googlemapsample;

import android.content.pm.PackageManager;
import android.location.Location;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Toast;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback,
        GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener,
        GoogleMap.OnMarkerDragListener,
        GoogleMap.OnMapLongClickListener,
        GoogleMap.OnMarkerClickListener,
        View.OnClickListener {

    private static final String TAG = "MapsActivity";
    private GoogleMap mMap;
    private double longitude;
    private double latitude;
    private GoogleApiClient googleApiClient;


    @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.
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);

        //Initializing googleApiClient
        googleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
    }


    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;
        mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
       // googleMapOptions.mapType(googleMap.MAP_TYPE_HYBRID)
                    //    .compassEnabled(true);

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

    //Getting current location
    private void getCurrentLocation() {
        mMap.clear();
        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 = LocationServices.FusedLocationApi.getLastLocation(googleApiClient);
        if (location != null) {
            //Getting longitude and latitude
            longitude = location.getLongitude();
            latitude = location.getLatitude();

            //moving the map to location
            moveMap();
        }
    }

    private void moveMap() {
        /**
         * Creating the latlng object to store lat, long coordinates
         * adding marker to map
         * move the camera with animation
         */
        LatLng latLng = new LatLng(latitude, longitude);
        mMap.addMarker(new MarkerOptions()
                .position(latLng)
                .draggable(true)
                .title("Marker in India"));

        mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
        mMap.animateCamera(CameraUpdateFactory.zoomTo(15));
        mMap.getUiSettings().setZoomControlsEnabled(true);


    }

    @Override
    public void onClick(View view) {
        Log.v(TAG,"view click event");
    }

    @Override
    public void onConnected(@Nullable Bundle bundle) {
        getCurrentLocation();
    }

    @Override
    public void onConnectionSuspended(int i) {

    }

    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {

    }

    @Override
    public void onMapLongClick(LatLng latLng) {
        // mMap.clear();
        mMap.addMarker(new MarkerOptions().position(latLng).draggable(true));
    }

    @Override
    public void onMarkerDragStart(Marker marker) {
        Toast.makeText(MapsActivity.this, "onMarkerDragStart", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onMarkerDrag(Marker marker) {
        Toast.makeText(MapsActivity.this, "onMarkerDrag", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onMarkerDragEnd(Marker marker) {
        // getting the Co-ordinates
        latitude = marker.getPosition().latitude;
        longitude = marker.getPosition().longitude;

        //move to current position
        moveMap();
    }

    @Override
    protected void onStart() {
        googleApiClient.connect();
        super.onStart();
    }

    @Override
    protected void onStop() {
        googleApiClient.disconnect();
        super.onStop();
    }


    @Override
    public boolean onMarkerClick(Marker marker) {
        Toast.makeText(MapsActivity.this, "onMarkerClick", Toast.LENGTH_SHORT).show();
        return true;
    }

}

Answer 4

如果您不需要在每次更改时检索用户的位置（我不知道为什么几乎每个解决方案都使用位置侦听器来这样做），那么这样做只是浪费。询问者显然有兴趣只检索一次位置。现在 FusedLocationApi 已弃用，因此作为 @Andrey 帖子的替代品，您可以执行以下操作：

    LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
    String locationProvider = LocationManager.NETWORK_PROVIDER;
    // I suppressed the missing-permission warning because this wouldn't be executed in my 
    // case without location services being enabled
    @SuppressLint("MissingPermission") android.location.Location lastKnownLocation = locationManager.getLastKnownLocation(locationProvider);
    double userLat = lastKnownLocation.getLatitude();
    double userLong = lastKnownLocation.getLongitude();

这只是将文档中的一些零散信息放在一起，这是最重要的来源。

Answer 5

1. 选择谷歌地图活动

   

2. 您需要一个 Google 地图 API 密钥。

   要获取一个，请点击此链接，按照说明进行操作，然后按最后的“创建”： https://console.developers.google.com/flows/enableapi?apiid=maps_android_backend&keyType=CLIENT_SIDE_ANDROID&r=48:C7:A8:5B： 31:4F:78:F2:38:41:97:F4:70:C3:A0:EB:6A:73:28:88%3Bcom.example.myapplication

3. 将此代码粘贴到 MapsActivity.java 中

import android.Manifest;
import android.content.pm.PackageManager;
import android.location.Location;
import android.os.Build;

import android.os.Bundle;

import android.widget.Toast;

import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import androidx.fragment.app.FragmentActivity;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;



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

    @private GoogleMap mMap;
        GoogleApiClient mGoogleApiClient;
        Location mLastLocation;
        Marker mCurrLocationMarker;
        LocationRequest mLocationRequest;
        @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();
            }
            // 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) {
            mMap = googleMap;


            //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);
            }
        }

        protected synchronized void buildGoogleApiClient() {
            mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
            mGoogleApiClient.connect();
        }

        @Override
        public void onConnected(Bundle bundle) {

            mLocationRequest = new LocationRequest();
            mLocationRequest.setInterval(1000);
            mLocationRequest.setFastestInterval(1000);
            mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
            if (ContextCompat.checkSelfPermission(this,
                    Manifest.permission.ACCESS_FINE_LOCATION) ==
                PackageManager.PERMISSION_GRANTED) {
                LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
            }

        }

        @Override
        public void onConnectionSuspended(int i) {

        }

        @Override
        public void onLocationChanged(Location location) {

            mLastLocation = location;
            if (mCurrLocationMarker != null) {
                mCurrLocationMarker.remove();
            }

            //Place current location marker
            LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
            MarkerOptions markerOptions = new MarkerOptions();
            markerOptions.position(latLng);
            markerOptions.title("Current Position");
            markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA));
            mCurrLocationMarker = mMap.addMarker(markerOptions);

            //move map camera
            mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
            mMap.animateCamera(CameraUpdateFactory.zoomTo(14));

            //stop location updates
            if (mGoogleApiClient != null) {
                LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
            }

        }

        @Override
        public void onConnectionFailed(ConnectionResult connectionResult) {

        }

        public static final int MY_PERMISSIONS_REQUEST_LOCATION = 99;
        public boolean checkLocationPermission() {
            if (ContextCompat.checkSelfPermission(this,
                    Manifest.permission.ACCESS_FINE_LOCATION) !=
                PackageManager.PERMISSION_GRANTED) {

                // Asking user if explanation is needed
                if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                        Manifest.permission.ACCESS_FINE_LOCATION)) {

                    // Show an explanation to the user *asynchronously* -- don't block
                    // this thread waiting for the user's response! After the user
                    // sees the explanation, try again to request the permission.

                    //Prompt the user once explanation has been shown
                    ActivityCompat.requestPermissions(this,
                        new String[] {
                            Manifest.permission.ACCESS_FINE_LOCATION
                        },
                        MY_PERMISSIONS_REQUEST_LOCATION);


                } else {
                    // No explanation needed, we can request the permission.
                    ActivityCompat.requestPermissions(this,
                        new String[] {
                            Manifest.permission.ACCESS_FINE_LOCATION
                        },
                        MY_PERMISSIONS_REQUEST_LOCATION);
                }
                return false;
            } else {
                return true;
            }
        }

        @Override
        public void onRequestPermissionsResult(int requestCode,
            String permissions[], int[] grantResults) {
            switch (requestCode) {
                case MY_PERMISSIONS_REQUEST_LOCATION:
                    {
                        // If request is cancelled, the result arrays are empty.
                        if (grantResults.length > 0 &&
                            grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                            // permission was granted. Do the
                            // contacts-related task you need to do.
                            if (ContextCompat.checkSelfPermission(this,
                                    Manifest.permission.ACCESS_FINE_LOCATION) ==
                                PackageManager.PERMISSION_GRANTED) {

                                if (mGoogleApiClient == null) {
                                    buildGoogleApiClient();
                                }
                                mMap.setMyLocationEnabled(true);
                            }

                        } else {

                            // Permission denied, Disable the functionality that depends on this permission.
                            Toast.makeText(this, "permission denied", Toast.LENGTH_LONG).show();
                        }
                        return;
                    }


            }
        }
    }

4. 确保这些权限写入Manifest文件中

   <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

   

5. 添加以下依赖项

   implementation 'com.google.android.gms:play-services-maps:17.0.0'

   implementation 'com.google.android.gms:play-services-location:17.0.0'

   

Answer 6

MapsActivity课堂中的此代码对我有用：

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

private GoogleMap mMap;
LocationManager locationManager;
LocationListener locationListener;

public void centreMapOnLocation(Location location, String title){

    LatLng userLocation = new LatLng(location.getLatitude(),location.getLongitude());
    mMap.clear();
    mMap.addMarker(new MarkerOptions().position(userLocation).title(title));
    mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(userLocation,12));

}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);

    if (grantResults.length>0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){

        if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED){
            locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0,locationListener);

            Location lastKnownLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
            centreMapOnLocation(lastKnownLocation,"Your Location");
        }
    }
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_maps2);
    // 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) {
    mMap = googleMap;

    Intent intent = getIntent();
    if (intent.getIntExtra("Place Number",0) == 0 ){

        // Zoom into users location
        locationManager = (LocationManager)this.getSystemService(Context.LOCATION_SERVICE);
        locationListener = new LocationListener() {
            @Override
            public void onLocationChanged(Location location) {
                centreMapOnLocation(location,"Your Location");
            }

            @Override
            public void onStatusChanged(String s, int i, Bundle bundle) {

            }

            @Override
            public void onProviderEnabled(String s) {

            }

            @Override
            public void onProviderDisabled(String s) {

            }
        };

        if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED){
            locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0,locationListener);
                Location lastKnownLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
                centreMapOnLocation(lastKnownLocation,"Your Location");
        } else {

            ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.ACCESS_FINE_LOCATION},1);
        }
    }


}


}