如何从Android上的地址获取经度和纬度？

Question

I am beginner in Android and I am working to create the Google Map which is able to mark the specific location from address.

For now, my following code is able to mark "empire state building" but nothing others..:< I want to know how to get latitude and longitude from street address or full address, and mark it on the map.

I modified the manifest file for supporting Google Map view like INTERNET and ACCESS_COARSE_LOCATION

Thank you.

package cs2340.kiwi.HelloGoogleMaps;

import java.io.IOException;
import java.util.List;
import java.util.Locale;

import android.graphics.drawable.Drawable;
import android.location.Address;
import android.location.Geocoder;
import android.os.Bundle;

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.Overlay;
import com.google.android.maps.OverlayItem;

public class HelloGoogleMapsActivity extends MapActivity {
    /** Called when the activity is first created. */
    @Override
    protected boolean isRouteDisplayed() {
        return false;
    }
    public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    MapView mapView = (MapView) findViewById(R.id.mapview);
    mapView.setBuiltInZoomControls(true);

    List<Overlay> mapOverlays = mapView.getOverlays();
    Drawable drawable = this.getResources().getDrawable(R.drawable.androidmarker);
    HelloItemizedOverlay itemizedoverlay = new HelloItemizedOverlay(drawable, this);

    Geocoder coder = new Geocoder(HelloGoogleMapsActivity.this, Locale.getDefault());

    List<Address> address;
    String strAddress = "empire state building";
    GeoPoint p1 = new GeoPoint(0,0);
    Double latitude;
    Double longitude;
    MapController mc = mapView.getController();

    try {
        address = coder.getFromLocationName(strAddress,5);
        Address location = address.get(0);
        latitude = location.getLatitude() * 1E6;        
        longitude = location.getLongitude() * 1E6;

        p1 = new GeoPoint( latitude.intValue(),
                           longitude.intValue());

        mc.animateTo(p1);    
        mapView.invalidate();
    }
    catch (IOException e){}
    OverlayItem overlayitem2 = new OverlayItem(p1, "Hello", "not working");

    itemizedoverlay.addOverlay(overlayitem2);
    mapOverlays.add(itemizedoverlay);

}
}

Here is my another class

package cs2340.kiwi.HelloGoogleMaps;

import java.util.ArrayList;

import android.app.AlertDialog;
import android.content.Context;
import android.graphics.drawable.Drawable;

import com.google.android.maps.ItemizedOverlay;
import com.google.android.maps.OverlayItem;

public class HelloItemizedOverlay extends ItemizedOverlay {

private ArrayList<OverlayItem> mOverlays = new ArrayList<OverlayItem>();
private Context mContext;

public HelloItemizedOverlay(Drawable defaultMarker, Context context) {
      super(boundCenterBottom(defaultMarker));
      mContext = context;
    }

public void addOverlay(OverlayItem overlay) {
    mOverlays.add(overlay);
    populate();
}

protected OverlayItem createItem(int i) {
      return mOverlays.get(i);
}

public int size() {
      return mOverlays.size();
}

protected boolean onTap(int index) {
      OverlayItem item = mOverlays.get(index);
      AlertDialog.Builder dialog = new AlertDialog.Builder(mContext);
      dialog.setTitle(item.getTitle());
      dialog.setMessage(item.getSnippet());
      dialog.show();
      return true;
}

}

Answer 1

尝试地理编码服务。向服务发送http请求，然后读取响应并在地图上放置标记。

Answer 2

http://maps.googleapis.com/maps/api/geocode/json?address=hyderabad&sensor=true_or_false

or

http://maps.googleapis.com/maps/api/geocode/xml?address=hyderabad&sensor=true_or_false

use any one of the url just replace your desired address and have a network hit then it will return a list of related lat and long from google server.

Answer 3

To get Latitude and Longitude from street address or full address do following:

int maxResults = 5;
String address = "Example Road 15";

Geocoder geo = new Geocoder( context, Locale.getDefault() );
List<Address> addresses = geo.getFromLocationName( address, maxResults );

for ( Address a : adresses ) 
   map.addMarker( new MarkerOptions().position( new LatLng( a.getLatitude(), a.getLongitude() ) ).title( "Hello" ).snippet( "Description about me!" ) );