/**
         * 绘制弧线
         * 
         * @return 折线对象
         */
        public Graphic DrawArc()
        {
            double mLat = 39.97923;
            double mLon = 116.357428;

            int lat = (int)(mLat * 1E6);
            int lon = (int)(mLon * 1E6);
            GeoPoint pt1 = new GeoPoint(lat, lon);

            mLat = 39.94923;
            mLon = 116.397428;
            lat = (int)(mLat * 1E6);
            lon = (int)(mLon * 1E6);
            GeoPoint pt2 = new GeoPoint(lat, lon);
            mLat = 39.97923;
            mLon = 116.437428;
            lat = (int)(mLat * 1E6);
            lon = (int)(mLon * 1E6);
            GeoPoint pt3 = new GeoPoint(lat, lon);

            Geometry arcGeometry = new Geometry();

            arcGeometry.SetArc(pt1, pt3, pt2);
            // 设定样式
            Symbol arcSymbol = new Symbol();
            Symbol.Color arcColor = new Com.Baidu.Mapapi.Map.Symbol.Color(arcSymbol);
            arcColor.Red = 255;
            arcColor.Green = 0;
            arcColor.Blue = 225;
            arcColor.Alpha = 255;
            arcSymbol.SetLineSymbol(arcColor, 4);
            // 生成Graphic对象
            Graphic arcGraphic = new Graphic(arcGeometry, arcSymbol);
            return arcGraphic;
        }