(Android 地图开发) 高德地图添加覆盖物

效果截图：

源代码：

package com.rf.mapabc; 
 
import com.amap.mapapi.core.GeoPoint; 
import com.amap.mapapi.map.MapActivity; 
import com.amap.mapapi.map.MapController; 
import com.amap.mapapi.map.MapView; 
import com.amap.mapapi.map.Overlay; 
import com.amap.mapapi.map.Projection; 
import com.baidu.location.BDLocation; 
import com.baidu.location.BDLocationListener; 
import com.baidu.location.LocationClient; 
import com.baidu.location.LocationClientOption; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.graphics.Point; 
import android.os.Bundle; 
import android.os.Handler; 
import android.os.Message; 
 
public class MainActivity extends MapActivity { 
	private MapView mMapView; 
	private MapController mMapController; 
	private GeoPoint point; 
 
	// 百度地图LBS定位 
	private LocationClient mLocationClient; 
	private MyLocationListener locationlistener; 
 
	// 主线程Handler 
	private Handler handler = new Handler() { 
		@Override 
		public void handleMessage(Message msg) { 
			// TODO Auto-generated method stub 
			switch (msg.what) { 
			case 0: 
				Bundle bundle = msg.getData(); 
				double lat = bundle.getDouble("x"); 
				double lng = bundle.getDouble("y"); 
				point = new GeoPoint((int) (lat * 1E6), (int) (lng * 1E6)); 
				MyOverlays overlay = new MyOverlays(point); 
 
				mMapController.setCenter(point); // 设置地图中心点 
				mMapController.setZoom(12); // 设置地图zoom级别 
 
				mMapView.getOverlays().clear(); 
				mMapView.getOverlays().add(overlay); 
				break; 
			} 
		} 
	}; 
 
	@Override 
	/** 
	 *显示栅格地图，启用内置缩放控件，并用MapController控制地图的中心点及Zoom级别 
	 */ 
	public void onCreate(Bundle savedInstanceState) { 
		super.onCreate(savedInstanceState); 
		setContentView(R.layout.mapview); 
		// 获取地图组件 
		mMapView = (MapView) findViewById(R.id.mapView); 
		mMapView.setBuiltInZoomControls(true); // 设置启用内置的缩放控件 
		mMapController = mMapView.getController(); // 得到mMapView的控制权,可以用它控制和驱动平移和缩放 
		point = new GeoPoint((int) (39.982378 * 1E6), (int) (116.304923 * 1E6)); // 用给定的经纬度构造一个GeoPoint，单位是微度 
																					// (度 
																					// * 
																					// 1E6) 
		mMapController.setCenter(point); // 设置地图中心点 
		mMapController.setZoom(12); // 设置地图zoom级别 
 
		// 百度地位 
		mLocationClient = new LocationClient(this); 
		locationlistener = new MyLocationListener(handler); 
		mLocationClient.registerLocationListener(locationlistener); 
		mLocationClient.start(); 
		if (mLocationClient != null && mLocationClient.isStarted()) { 
			setLocationOption(); 
			mLocationClient.requestLocation(); 
		} 
	} 
 
	// 实时位置的显示的问题（LBS） 
	public class MyLocationListener implements BDLocationListener { 
		private Handler handle; 
 
		public MyLocationListener(Handler handle) { 
			super(); 
			this.handle = handle; 
		} 
 
		@Override 
		public void onReceiveLocation(BDLocation location) { 
			// TODO Auto-generated method stub 
			// 获取经纬度 
			double x = location.getLatitude(); 
			double y = location.getLongitude(); 
 
			Message message = new Message(); 
			Bundle bundle = new Bundle(); 
			bundle.putDouble("x", x); 
			bundle.putDouble("y", y); 
			message.setData(bundle); 
			message.what = 0; 
			handle.sendMessage(message); 
 
		} 
 
		@Override 
		public void onReceivePoi(BDLocation arg0) { 
			// TODO Auto-generated method stub 
		} 
	} 
 
	// 查询条件显示 
	private void setLocationOption() { 
		LocationClientOption option = new LocationClientOption(); 
		option.setOpenGps(true); 
		option.setAddrType("all");// 返回的定位结果包含地址信息 
		option.setCoorType("bd09ll");// 返回的定位结果是百度经纬度,默认值gcj02 
		option.setScanSpan(5000);// 设置发起定位请求的间隔时间为5000ms 
		option.disableCache(true);// 禁止启用缓存定位 
		option.setPoiNumber(5); // 最多返回POI个数 
		option.setPoiDistance(1000); // poi查询距离 
		option.setPoiExtraInfo(true); // 是否需要POI的电话和地址等详细信息 
		mLocationClient.setLocOption(option); 
	} 
 
	// 地图添加覆盖物（Overlay覆盖物的基类） 
	public class MyOverlays extends Overlay { 
		// 经纬度坐标 
		GeoPoint gp; 
 
		public MyOverlays(GeoPoint gp) { 
			super(); 
			this.gp = gp; 
		} 
 
		@Override 
		public void draw(Canvas canvas, MapView mapView, boolean arg2) { 
			// TODO Auto-generated method stub 
			// 获取mapView 的Projection对象 
			Projection projection = mapView.getProjection(); 
			Point point = new Point(); 
			// 将地理位置转化为屏幕坐标 
			projection.toPixels(gp, point); 
			// 画笔相关设置 
			Paint paintText = new Paint(); 
			paintText.setColor(Color.BLUE); 
			paintText.setTextSize(18); 
			// 图片资源 
			Bitmap pic = BitmapFactory.decodeResource(getResources(), 
					R.drawable.da_marker_red); // 得到Bitmap对象 
			canvas.drawBitmap(pic, point.x - 20, point.y - 32, paintText); // 绘图 
			// 绘制文本 
			paintText.setAlpha(18); 
			canvas.drawCircle(point.x, point.y, 120, paintText); 
 
		} 
 
	} 
}