LocationOverlay.java

package com.baidu.mapapi.demo;

import android.content.Intent;
import android.location.Location;
import android.os.Bundle;

import com.baidu.mapapi.BMapManager;
import com.baidu.mapapi.GeoPoint;
import com.baidu.mapapi.LocationListener;
import com.baidu.mapapi.MapActivity;
import com.baidu.mapapi.MapView;
import com.baidu.mapapi.MyLocationOverlay;

public class LocationOverlay extends MapActivity {

	MapView mMapView = null;
	LocationListener mLocationListener = null;//onResumeʱע���listener��onPauseʱ��ҪRemove
	MyLocationOverlay mLocationOverlay = null;	//��λͼ��
	
	protected void onCreate(Bundle savedInstanceState) {
		
		super.onCreate(savedInstanceState);
        setContentView(R.layout.mapviewdemo);
        
		BMapApiDemoApp app = (BMapApiDemoApp)this.getApplication();
		if (app.mBMapMan == null) {
			app.mBMapMan = new BMapManager(getApplication());
			app.mBMapMan.init(app.mStrKey, new BMapApiDemoApp.MyGeneralListener());
		}
		app.mBMapMan.start();
        // ���ʹ�õ�ͼSDK�����ʼ����ͼActivity
        super.initMapActivity(app.mBMapMan);
        
        mMapView = (MapView)findViewById(R.id.bmapView);
        mMapView.setBuiltInZoomControls(true);
        //���������Ŷ���������Ҳ��ʾoverlay,Ĭ��Ϊ������
        mMapView.setDrawOverlayWhenZooming(true);
        
		// ��Ӷ�λͼ��
        mLocationOverlay = new MyLocationOverlay(this, mMapView);
		mMapView.getOverlays().add(mLocationOverlay);		
        // ע�ᶨλ�¼�
        mLocationListener = new LocationListener(){

			@Override
			public void onLocationChanged(Location location) {
				if (location != null){
					GeoPoint pt = new GeoPoint((int)(location.getLatitude()*1e6),
							(int)(location.getLongitude()*1e6));
					mMapView.getController().animateTo(pt);
				}
			}
        };
	}

	@Override
	protected void onPause() {
		BMapApiDemoApp app = (BMapApiDemoApp)this.getApplication();
		app.mBMapMan.getLocationManager().removeUpdates(mLocationListener);
		mLocationOverlay.disableMyLocation();
        mLocationOverlay.disableCompass(); // �ر�ָ����
		app.mBMapMan.stop();
		super.onPause();
	}
	@Override
	protected void onResume() {
		BMapApiDemoApp app = (BMapApiDemoApp)this.getApplication();
		// ע�ᶨλ�¼�����λ�󽫵�ͼ�ƶ�����λ��
        app.mBMapMan.getLocationManager().requestLocationUpdates(mLocationListener);
        mLocationOverlay.enableMyLocation();
        mLocationOverlay.enableCompass(); // ��ָ����
		app.mBMapMan.start();
		super.onResume();
	}

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

}