无法使用android maps活动和Fused Location API获取我的当前位置

Question

I am trying to get my current location using GoogleApiClient and LocationListner. Below is my code which I got from Here . But the problem is when I start this app in mobile. It is not giving me my current location. I also have checked in debug mode. Latitude and Longitude are not updating in variables. Please check this code and guide me where i am doing wrong or any other logical error. In tutorial developer make a boolean type function named checkLocationPermission() . But this function never used in application. Where should I call that function.

Thanks in advance

Here are my coding files AndroidManifest.xml

`<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.sufian.androidmaps">
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <meta-data
            android:name="com.google.android.geo.API_KEY"
            android:value="@string/google_maps_key" />
        <activity
            android:name=".MapsActivity"
            android:label="@string/title_activity_maps">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>`

and My MapsActivity.java File is below `

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

    private GoogleMap mMap;
    GoogleApiClient mGoogleApiClient;
    LocationRequest mLocationRequest;
    Location mLastLocation;
    Marker mCurrLocationMarker;

    @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);
    }
    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;
        //mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);

        //initialize google play services
        if(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 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(11));

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

    }

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

    }

    @Override
    public void onProviderEnabled(String s) {

    }

    @Override
    public void onProviderDisabled(String s) {

    }

    public static final int MY_PERMISSIONS_REQUEST_LOCATION = 100;
    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)) {

                //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.
                    if (ContextCompat.checkSelfPermission(this,
                            Manifest.permission.ACCESS_FINE_LOCATION)
                            == PackageManager.PERMISSION_GRANTED) {

                        if (mGoogleApiClient == null) {
                            buildGoogleApiClient();
                        }
                        mMap.setMyLocationEnabled(true);
                    }
                } else {
                    //toast here
                }
                return;
            }
        }
    }
    @Override
    public void onConnected(@Nullable 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,
            (com.google.android.gms.location.
            LocationListener) this);
        }
    }
    @Override
    public void onConnectionSuspended(int i){
    }

Answer 1

The reason your not receiving update locations is because you check if you have location permissions which you don't have before building the Google ApiClient which triggers the location updates.

From Android 6 and higher these aren't granted automatically. But if you call checkLocationPermission() in OnCreate it should prompt the user to grant the permission as soon as you launch the activity