谷歌地图地理位置不起作用

Question

>我正在尝试在安卓上的谷歌地图中启用自动定位功能，我已经添加了代码

mMap.setMyLocationEnabled(true(;mMap.getUiSettings((.setMyLocationButtonEnabled(true(;

要启用该功能，但位置的蓝点不会显示，任何帮助将不胜感激

    package com.example.runnable;
import android.Manifest;
import android.content.pm.PackageManager;
import android.location.Criteria;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.FragmentActivity;
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.MarkerOptions;
import static com.example.runnable.R.id.map;
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
    private GoogleMap mMap;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // 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;
        // Add a marker in Sydney and move the camera
        mMap.addMarker(new MarkerOptions().position(new LatLng(54.581765, -5.937637)).title("Marker"));

        // Enabling MyLocation Layer of Google Map
        googleMap.setMyLocationEnabled(true);
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, 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;
        }
        mMap.setMyLocationEnabled(true);
        mMap.getUiSettings().setMyLocationButtonEnabled(true);
    }
}

Answer 1

private static final int REQUEST_FINE_LOCATION = 1001;
@Override
public void onMapReady(GoogleMap googleMap) {
  mMap = googleMap;
  // Add a marker in Sydney and move the camera
  mMap.addMarker(new MarkerOptions().position(new LatLng(54.581765, -5.937637)).title("Marker"));
  checkLocationPermission();
}
protected void checkLocationPermission() {
  if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED 
      || ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
    this.googleMap.setMyLocationEnabled(true);
  }
  else {
    requestFineLocationPermission();
  }
}
protected void requestFineLocationPermission() {
  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    if (shouldShowRequestPermissionRationale(Manifest.permission.ACCESS_FINE_LOCATION)) {
      Toast.makeToast(this, "Provide Location Permission", Toast.LENGTH_LONG).show();
    }
    else {
      requestPermissions(new String[] { Manifest.permission.ACCESS_FINE_LOCATION }, REQUEST_FINE_LOCATION);
    }
  }
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
  super.onRequestPermissionsResult(requestCode, permissions, grantResults);
  switch (requestCode) {
    case REQUEST_FINE_LOCATION:
      checkLocationPermission();
  }
}

Answer 2

private GoogleMap.OnMyLocationChangeListener myLocationChangeListener =        new GoogleMap.OnMyLocationChangeListener() {
@Override
public void onMyLocationChange(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 = mGoogleMap.addMarker(markerOptions);
//move map camera
mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng,11));
//optionally, stop location updates if only current location is needed
if (mGoogleApiClient != null) {
    LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
    }
   }
};