Question

我想使用谷歌地图显示我在Android手机上的当前位置。以下代码是否能够在谷歌地图上显示我当前的位置？

MapsActivity.java

package log1.log2;

import log1.log2.MyLocation.LocationResult;

import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;
import com.google.android.maps.MapView.LayoutParams;

import android.location.Criteria;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.View;
import android.widget.LinearLayout;

public class MapsActivity extends MapActivity 
{    
    MapView mapView; 
    MapController mc;
    GeoPoint p;

    /** Called when the activity is first created. */
    @SuppressWarnings("deprecation")
    @Override
    public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.mapactivity);

        mapView = (MapView) findViewById(R.id.mapView);
        LinearLayout zoomLayout = (LinearLayout)findViewById(R.id.zoom);  
        View zoomView = mapView.getZoomControls(); 
        zoomLayout.addView(zoomView, 
            new LinearLayout.LayoutParams(
                LayoutParams.WRAP_CONTENT, 
                LayoutParams.WRAP_CONTENT)); 
        mapView.displayZoomControls(true);
    }
    MyLocation myLocation = new MyLocation();
    private void locationClick() {
        myLocation.getLocation(this, locationResult);
    }

    public LocationResult locationResult = new LocationResult(){
        public void gotLocation(final Location location){
            //Got the location!
            };
        };

    @Override
    protected boolean isRouteDisplayed() {
        // TODO Auto-generated method stub
        return false;
    }
}

MyLocation.java

package log1.log2;

import java.util.Timer;
import java.util.TimerTask;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;

public class MyLocation {
    Timer timer1;
    LocationManager lm;
    LocationResult locationResult;
    boolean gps_enabled=false;
    boolean network_enabled=false;

    public boolean getLocation(Context context, LocationResult result)
    {
        //I use LocationResult callback class to pass location value from MyLocation to user code.
        locationResult=result;
        if(lm==null)
            lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);

        //exceptions will be thrown if provider is not permitted.
        try{gps_enabled=lm.isProviderEnabled(LocationManager.GPS_PROVIDER);}catch(Exception ex){}
        try{network_enabled=lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);}catch(Exception ex){}

        //don't start listeners if no provider is enabled
        if(!gps_enabled && !network_enabled)
            return false;

        if(gps_enabled)
            lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListenerGps);
        if(network_enabled)
            lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListenerNetwork);
        timer1=new Timer();
        timer1.schedule(new GetLastLocation(), 20000);
        return true;
    }

    LocationListener locationListenerGps = new LocationListener() {
        public void onLocationChanged(Location location) {
            timer1.cancel();
            locationResult.gotLocation(location);
            lm.removeUpdates(this);
            lm.removeUpdates(locationListenerNetwork);
        }
        public void onProviderDisabled(String provider) {}
        public void onProviderEnabled(String provider) {}
        public void onStatusChanged(String provider, int status, Bundle extras) {}
    };

    LocationListener locationListenerNetwork = new LocationListener() {
        public void onLocationChanged(Location location) {
            timer1.cancel();
            locationResult.gotLocation(location);
            lm.removeUpdates(this);
            lm.removeUpdates(locationListenerGps);
        }
        public void onProviderDisabled(String provider) {}
        public void onProviderEnabled(String provider) {}
        public void onStatusChanged(String provider, int status, Bundle extras) {}
    };

    class GetLastLocation extends TimerTask {
        @Override
        public void run() {
             lm.removeUpdates(locationListenerGps);
             lm.removeUpdates(locationListenerNetwork);

             Location net_loc=null, gps_loc=null;
             if(gps_enabled)
                 gps_loc=lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
             if(network_enabled)
                 net_loc=lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);

             //if there are both values use the latest one
             if(gps_loc!=null && net_loc!=null){
                 if(gps_loc.getTime()>net_loc.getTime())
                     locationResult.gotLocation(gps_loc);
                 else
                     locationResult.gotLocation(net_loc);
                 return;
             }

             if(gps_loc!=null){
                 locationResult.gotLocation(gps_loc);
                 return;
             }
             if(net_loc!=null){
                 locationResult.gotLocation(net_loc);
                 return;
             }
             locationResult.gotLocation(null);
        }
    }

    public static abstract class LocationResult{
        public abstract void gotLocation(Location location);
    }
}

谢谢。

Answer 1

如果您只想显示自己的位置，那么MyLocationOverlay可能最简单。

此处的快速信息（该文章的其余部分也可能有用）：

http://www.vogella.com/articles/AndroidLocationAPI/article.html#maps_mylocation

关于无法在模拟器中测试它：您可以测试它。在Eclipse中切换到DDMS Perspective，在左侧看到“Emulator Control”，您可以在“Location Controls”下面“发送”位置。这在上面的教程中也有描述。

Answer 2

不知道我没有通过代码但是以下代码适用于我：

public class GoogleMapsActivity extends MapActivity {
    public static final String TAG = "GoogleMapsActivity";
    private MapView mapView;
    private LocationManager locationManager;
    Geocoder geocoder;
    Location location;
    LocationListener locationListener;
    CountDownTimer locationtimer;
    MapController mapController;
    MapOverlay mapOverlay = new MapOverlay();

    @Override
    protected void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.googlemap);
        initComponents();
        mapView.setBuiltInZoomControls(true);
        mapView.setSatellite(true);
        mapController = mapView.getController();
        mapController.setZoom(16);
        locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
        if (locationManager == null) {
            Toast.makeText(GoogleMapsActivity.this,
                    "Location Manager Not Available", Toast.LENGTH_SHORT)
                    .show();
            return;
        }
        location = locationManager
                .getLastKnownLocation(LocationManager.GPS_PROVIDER);
        if (location == null)
            location = locationManager
                    .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
        if (location != null) {
            double lat = location.getLatitude();
            double lng = location.getLongitude();
            Toast.makeText(GoogleMapsActivity.this,
                    "Location Are" + lat + ":" + lng, Toast.LENGTH_SHORT)
                    .show();
            GeoPoint point = new GeoPoint((int) (lat * 1E6), (int) (lng * 1E6));
            mapController.animateTo(point, new Message());
            mapOverlay.setPointToDraw(point);
            List<Overlay> listOfOverlays = mapView.getOverlays();
            listOfOverlays.clear();
            listOfOverlays.add(mapOverlay);
        }
        locationListener = new LocationListener() {
            @Override
            public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
            }

            @Override
            public void onProviderEnabled(String arg0) {
            }

            @Override
            public void onProviderDisabled(String arg0) {
            }

            @Override
            public void onLocationChanged(Location l) {
                location = l;
                locationManager.removeUpdates(this);
                if (l.getLatitude() == 0 || l.getLongitude() == 0) {
                } else {
                    double lat = l.getLatitude();
                    double lng = l.getLongitude();
                    Toast.makeText(GoogleMapsActivity.this,
                            "Location Are" + lat + ":" + lng,
                            Toast.LENGTH_SHORT).show();
                }
            }
        };
        if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER))
            locationManager.requestLocationUpdates(
                    LocationManager.GPS_PROVIDER, 1000, 10f, locationListener);
        locationManager.requestLocationUpdates(
                LocationManager.NETWORK_PROVIDER, 1000, 10f, locationListener);
        locationtimer = new CountDownTimer(30000, 5000) {
            @Override
            public void onTick(long millisUntilFinished) {
                if (location != null)
                    locationtimer.cancel();
            }

            @Override
            public void onFinish() {
                if (location == null) {
                }
            }
        };
        locationtimer.start();
    }

    public MapView getMapView() {
        return this.mapView;
    }

    private void initComponents() {
        mapView = (MapView) findViewById(R.id.googleMapview);
    }

    @Override
    protected boolean isRouteDisplayed() {
        return false;
    }

    class MapOverlay extends Overlay {
        private GeoPoint pointToDraw;

        public void setPointToDraw(GeoPoint point) {
            pointToDraw = point;
        }

        public GeoPoint getPointToDraw() {
            return pointToDraw;
        }

        @Override
        public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
                long when) {
            super.draw(canvas, mapView, shadow);

            Point screenPts = new Point();
            mapView.getProjection().toPixels(pointToDraw, screenPts);

            Bitmap bmp = BitmapFactory.decodeResource(getResources(),
                    R.drawable.pingreen);
            canvas.drawBitmap(bmp, screenPts.x, screenPts.y - 24, null);
            return true;
        }
    }

}

谷歌地图上的当前位置

2 个答案: