java - fusedLocationProviderClient 不工作和 MapActivity android

Question

fusedLocationProviderClient 不起作用。

包含 map API 和所有必需的依赖项这是我的功能:

private void fetchLastLocation() {
       if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(this, new String[]
                {Manifest.permission.ACCESS_FINE_LOCATION},REQUEST_CODE);
        return;
    }
    Task<Location> task = fusedLocationProviderClient.getLastLocation();
    task.addOnSuccessListener(new OnSuccessListener<Location>() {
        @Override
        public void onSuccess(Location location) {
            if(location != null){
                current = location;
                SupportMapFragment supportMapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.mapid);
                supportMapFragment.getMapAsync(HomeActivity.this);
            }
        }
    });
}

这是我的onMapReady(GoogleMap googleMap)函数:

@Override
public void onMapReady(GoogleMap googleMap) {
    if(current != null) {
        LatLng latLng = new LatLng(current.getLatitude(), current.getLongitude());
        MarkerOptions markerOptions = new MarkerOptions().position(latLng).title("I am here");
        googleMap.animateCamera(CameraUpdateFactory.newLatLng(latLng));
        googleMap.animateCamera(CameraUpdateFactory.newLatLngZoom(latLng,25));
        googleMap.addMarker(markerOptions);
    } /// 
 }

Answer 1

如果不提供完整的代码实现或您遇到的错误，很难说为什么您的应用无法运行，但我已经测试了您的 fetchLastLocation 和 onMapReady 方法，它们对我来说效果很好。请运行下面的代码。

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

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

import com.google.android.gms.location.FusedLocationProviderClient;
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 com.google.android.gms.tasks.OnSuccessListener;
import com.google.android.gms.tasks.Task;

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

    private FusedLocationProviderClient fusedLocationProviderClient;
    private Location current;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);

        fusedLocationProviderClient = new FusedLocationProviderClient(this);
        fetchLastLocation();
    }

    private void fetchLastLocation() {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this, new String[]
                    {Manifest.permission.ACCESS_FINE_LOCATION}, 200);
            return;
        }

        Task<Location> task = fusedLocationProviderClient.getLastLocation();
        task.addOnSuccessListener(new OnSuccessListener<Location>() {
            @Override
            public void onSuccess(Location location) {
                if (location != null) {
                    current = location;
                    SupportMapFragment supportMapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
                    supportMapFragment.getMapAsync(MapsActivity.this);
                }
            }
        });
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        if (current != null) {
            LatLng latLng = new LatLng(current.getLatitude(), current.getLongitude());
            MarkerOptions markerOptions = new MarkerOptions().position(latLng).title("I am here");
            googleMap.animateCamera(CameraUpdateFactory.newLatLng(latLng));
            googleMap.animateCamera(CameraUpdateFactory.newLatLngZoom(latLng, 25));
            googleMap.addMarker(markerOptions);
        } ///
    }
}

此外，我建议您仔细检查您是否已设置 a valid API key并且您已允许 location access在您的测试设备上。希望这可以帮助。如果有什么特别对您不起作用的地方，请告诉我，我会相应地修改我的答案。