学步园

在silverlight api中测距和测面积有多种实现方式，

     第一种，使用GeometryServer服务；

     第二种，使用行为动作MeasureAction；

     第三种，使用ESRI.ArcGIS.Client.Geometry.Euclidian类；
我主要说说第三种实现方式，前两种网上已经有很多资料了。

代码如下：

	private Draw _DrawTool;
	private EventHandler<DrawEventArgs> _DrawComplete;

	//测距
        public void Ranging(EventHandler<DrawEventArgs> drawComplete = null)
        {
            if (drawComplete == null) drawComplete = Ranging_Complete;
            CreateFreeBursh(drawComplete);
            _DrawTool.DrawMode = DrawMode.Polyline;
            OpenFreeBursh();
        }
        private void Ranging_Complete(object sender, DrawEventArgs e)
        {
            double length = Math.Abs(ESRI.ArcGIS.Client.Geometry.Euclidian.Length(e.Geometry as Polyline));
            if (length > 0)
            {
                this.Graphics.Add(new Graphic()
                {
                    Geometry = e.Geometry,
                    Symbol = new SimpleLineSymbol() { Color = new SolidColorBrush(Colors.Red), Width = 2 },
                });
                this.Graphics.Add(new Graphic()
                {
                    Geometry = (e.Geometry as Polyline).Paths.LastOrDefault().LastOrDefault(),
                    Symbol = new TextSymbol() { Text = string.Format("{0:F} km", length / 1000), FontFamily = new FontFamily("SimSun"), FontSize = 13 },
                });
            }
        }

        //测面积
        public void Polygon(EventHandler<DrawEventArgs> drawComplete = null)
        {
            if (drawComplete == null) drawComplete = Polygon_Complete;
            CreateFreeBursh(drawComplete);
            _DrawTool.DrawMode = DrawMode.Polygon;
            OpenFreeBursh();
        }
        private void Polygon_Complete(object sender, DrawEventArgs e)
        {
            double area = Math.Abs(ESRI.ArcGIS.Client.Geometry.Euclidian.Area(e.Geometry as Polygon));
            if (area > 0)
            {
                this.Graphics.Add(new Graphic()
                {
                    Geometry = e.Geometry,
                    Symbol = new SimpleFillSymbol() { Fill = new SolidColorBrush(AppColorManager.HtmlToColor("#22FF0000")), BorderBrush = new SolidColorBrush(Colors.Red), BorderThickness = 2 }
                });
                this.Graphics.Add(new Graphic()
                {
                    Geometry = (e.Geometry as Polygon).Rings.LastOrDefault().FirstOrDefault(),
                    Symbol = new TextSymbol() { Text = string.Format("{0:F} km2", area / 1000000), FontFamily = new FontFamily("SimSun"), FontSize = 13 },
                });
            }
        }