Question

我似乎无法根据GPS信号设置位置。这是模板，我试图遵循指南，但代码由于某种原因不执行。

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

    private GoogleMap mMap;

    @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);

    }


    /**
     * Manipulates the map once available.
     * This callback is triggered when the map is ready to be used.
     * This is where we can add markers or lines, add listeners or move the camera. In this case,
     * we just add a marker near Sydney, Australia.
     * If Google Play services is not installed on the device, the user will be prompted to install
     * it inside the SupportMapFragment. This method will only be triggered once the user has
     * installed Google Play services and returned to the app.
     */
    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

        // Add a marker in Sydney and move the camera
        LatLng middle = new LatLng(0, 0);
        mMap.addMarker(new MarkerOptions().position(middle).title("Marker at 0,0"));
        mMap.moveCamera(CameraUpdateFactory.newLatLng(middle));
    }
}

Answer 1

使用现已弃用的getMap()的旧模板使用了setUpMap()方法。

由于您使用的是getMapAsync()，因此您已经拥有onMapReady()方法，因此无需将代码分离到另一种方法中。

以下是来自my other answer的完整类代码，它使用LocationServices.FusedLocationApi将标记置于GPS或网络位置获取的当前位置：

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import android.location.Location;
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.LocationRequest;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.location.LocationListener;
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;
import com.google.android.gms.maps.OnMapReadyCallback;

public class MainActivity extends AppCompatActivity implements
        GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener,
        LocationListener,
        OnMapReadyCallback {

    LocationRequest mLocationRequest;
    GoogleApiClient mGoogleApiClient;

    LatLng latLng;
    GoogleMap mGoogleMap;
    SupportMapFragment mFragment;
    Marker mCurrLocation;

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

        mFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
        mFragment.getMapAsync(this);
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {

        mGoogleMap = googleMap;

        mGoogleMap.setMyLocationEnabled(true);

        buildGoogleApiClient();

        mGoogleApiClient.connect();
    }

    @Override
    public void onPause() {
        super.onPause();
        //Unregister for location callbacks:
        if (mGoogleApiClient != null) {
            LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
        }
    }

    protected synchronized void buildGoogleApiClient() {
        Toast.makeText(this,"buildGoogleApiClient",Toast.LENGTH_SHORT).show();
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
    }

    @Override
    public void onConnected(Bundle bundle) {
        Toast.makeText(this,"onConnected",Toast.LENGTH_SHORT).show();
        Location mLastLocation = LocationServices.FusedLocationApi.getLastLocation(
                mGoogleApiClient);
        if (mLastLocation != null) {
            //place marker at current position
            mGoogleMap.clear();
            latLng = new LatLng(mLastLocation.getLatitude(), mLastLocation.getLongitude());
            MarkerOptions markerOptions = new MarkerOptions();
            markerOptions.position(latLng);
            markerOptions.title("Current Position");
            markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA));
            mCurrLocation = mGoogleMap.addMarker(markerOptions);
        }

        mLocationRequest = new LocationRequest();
        mLocationRequest.setInterval(5000); //5 seconds
        mLocationRequest.setFastestInterval(3000); //3 seconds
        mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
        //mLocationRequest.setSmallestDisplacement(0.1F); //1/10 meter

        LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
    }

    @Override
    public void onConnectionSuspended(int i) {
        Toast.makeText(this,"onConnectionSuspended",Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {
        Toast.makeText(this,"onConnectionFailed",Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onLocationChanged(Location location) {

        //remove previous current location marker and add new one at current position
        if (mCurrLocation != null) {
            mCurrLocation.remove();
        }
        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));
        mCurrLocation = mGoogleMap.addMarker(markerOptions);

        Toast.makeText(this,"Location Changed",Toast.LENGTH_SHORT).show();

        //If you only need one location, unregister the listener
        //LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
    }

}

如何设置查找位置的方法？

1 个答案: