android百度地图半径画圆

Java代码 
import android.content.Context;  
import android.graphics.Canvas;  
import android.graphics.Color;  
import android.graphics.Paint;  
import android.graphics.Paint.Style;  
import android.graphics.Path;  
import android.graphics.Point;  
import android.os.Bundle;  
import com.baidu.mapapi.BMapManager;  
import com.baidu.mapapi.GeoPoint;  
import com.baidu.mapapi.MapActivity;  
import com.baidu.mapapi.MapController;  
import com.baidu.mapapi.MapView;  
import com.baidu.mapapi.Overlay;  
import com.baidu.mapapi.Projection;  
 
public class BaiduMapActivity extends MapActivity {  
        private Context mContext;  
        private MapView mapView;  
        @Override 
        protected boolean isRouteDisplayed() {  
                // TODO Auto-generated method stub  
                return false;  
        }  
        @Override 
        protected void onCreate(Bundle arg0) {  
                super.onCreate(arg0);  
                setContentView(R.layout.baidumap_layout);  
 
                BaseApplication baseApp = (BaseApplication) this.getApplication();  
                if (baseApp.mBMapManage == null) {  
                        baseApp.mBMapManage = new BMapManager(mContext);  
                        baseApp.mBMapManage.init(baseApp.mStrKey,  
                                        new BaseApplication.MyGeneralListener());  
                }  
                baseApp.mBMapManage.start();  
                super.initMapActivity(baseApp.mBMapManage);// 初始化map sdk  
                mapView = (MapView) findViewById(R.id.bmapView);  
                mapView.setBuiltInZoomControls(true);  
                // 设置在缩放动画过程中也显示overlay,默认为不绘制  
                mapView.setDrawOverlayWhenZooming(true);  
 
                // RouteLine routeLine =  
                // (RouteLine)getIntent().getSerializableExtra("routeLine");  
 
                //这里画点和连接线  
                MyOverlay myOverlay = new MyOverlay();  
                mapView.getOverlays().add(myOverlay);  
                  
                MapController mapController = mapView.getController();  
                mapController.zoomIn();  
            
                mapController.animateTo(new GeoPoint((int) (2259316 * 10),  
                                (int) (11396279 * 10)));//设置一个起点  
        }  
 
        class MyOverlay extends Overlay {  
 
                public void draw(Canvas canvas, MapView mapView, boolean shadow) {  
            super.draw(canvas, mapView, shadow);  
            Paint paint = new Paint();  
            paint.setColor(Color.BLUE);  
            paint.setDither(true);  
            paint.setStyle(Paint.Style.STROKE);  
            paint.setStrokeCap(Paint.Cap.ROUND);  
            paint.setStrokeJoin(Paint.Join.ROUND);  
            paint.setStrokeWidth(5);  
            Projection projection = mapView.getProjection();  
            Point p1 = new Point();  
            projection.toPixels(gpoint1 = new GeoPoint((int) (2259316 * 10), (int) (11396279 * 10)), p1);  
            canvas.drawCircle(p1.x, p1.y, projection.metersToEquatorPixels(500), paint);  
        }  
        }  
 
}