@Override
    public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
            long when) {
        super.draw(canvas, mapView, shadow);  
         
        Paint innerPaint = new Paint();  
        Paint borderPaint = new Paint();  
        innerPaint.setARGB(75, 80, 80, 80); // darkgray  
        borderPaint.setARGB(75, 101, 84, 199); // white  
        borderPaint.setAntiAlias(true); // 抗锯齿  
        borderPaint.setStyle(Style.STROKE); //描边，和Style.Fill相对  
        borderPaint.setStrokeWidth(2);  
         
        Projection projection = mapView.getProjection();
        Point p1 = new Point();
        projection.toPixels(p, p1);
         
        canvas.drawCircle(p1.x, p1.y, projection.metersToEquatorPixels(500), innerPaint);
        canvas.drawCircle(p1.x, p1.y, projection.metersToEquatorPixels(500), borderPaint);
        return true;  
    }
//java/6802