ArcgisEngine的鹰眼实现

  所谓的鹰眼，就是一个缩略地图，上面有一个矩形框，矩形框区域就是当前显示的地图区域，拖动矩形框可以改变当前地图显示的位置，改变矩形框的大小，可以改变当前地图的显示区域大小，从起到导航的作用。鹰眼是地图浏览中常用的功能之一。

 如下图:

 
 

 具体实现:

 一、载入地图到鹰眼控件:

 

  //当主地图显示控件的地图更换时，鹰眼中的地图也跟随更换
        private void axMapControl1_OnMapReplaced(object sender, IMapControlEvents2_OnMapReplacedEvent e)
        {
            this.axMapControl2.Map = new Map();
            // 添加主地图控件中的所有图层到鹰眼控件中
            for (int i = 1; i <= this.axMapControl1.LayerCount; i++)
            {
                this.axMapControl2.AddLayer(this.axMapControl1.get_Layer(this.axMapControl1.LayerCount - i));
            }
            // 设置 MapControl 显示范围至数据的全局范围
            this.axMapControl2.Extent = this.axMapControl1.FullExtent;
            // 刷新鹰眼控件地图
            this.axMapControl2.Refresh();
        }

 

 二、绘制鹰眼矩形框:

  为鹰眼控件 MapControl1 添加 OnExtentUpdated 事件，此事件是在主 Map 控件的显示范围改变时响应，从而相应更新鹰眼控件中的矩形框。其响应函数代码如下：

 

 private void axMapControl1_OnExtentUpdated(object sender, IMapControlEvents2_OnExtentUpdatedEvent e)
        {
            // 得到新范围
            IEnvelope pEnv = (IEnvelope)e.newEnvelope;
            IGraphicsContainer pGra = axMapControl2.Map as IGraphicsContainer;
            IActiveView pAv = pGra as IActiveView;
            // 在绘制前，清除 axMapControl2 中的任何图形元素
            pGra.DeleteAllElements();
            IRectangleElement pRectangleEle = new RectangleElement() as IRectangleElement;
            IElement pEle = pRectangleEle as IElement;
            pEle.Geometry = pEnv;
            // 设置鹰眼图中的红线框
            IRgbColor pColor = new RgbColor();
            pColor.Red = 255;
            pColor.Green = 0;
            pColor.Blue = 0;
            pColor.Transparency = 255;
            // 产生一个线符号对象
            ILineSymbol pOutline = new SimpleLineSymbol();
            pOutline.Width = 2;
            pOutline.Color = pColor;
            // 设置颜色属性
            pColor = new RgbColor();
            pColor.Red = 255;
            pColor.Green = 0;
            pColor.Blue = 0;
            pColor.Transparency = 0;
            // 设置填充符号的属性
            IFillSymbol pFillSymbol = new SimpleFillSymbol();
            pFillSymbol.Color = pColor;
            pFillSymbol.Outline = pOutline;
            IFillShapeElement pFillShapeEle = pEle as IFillShapeElement;
            pFillShapeEle.Symbol = pFillSymbol;
            pGra.AddElement((IElement)pFillShapeEle, 0);
            // 刷新
            pAv.PartialRefresh(esriViewDrawPhase.esriViewGraphics, null, null);
          
        }

 

 三、鹰眼与主 Map 控件互动:

 

private void axMapControl2_OnMouseDown(object sender, IMapControlEvents2_OnMouseDownEvent e){
            if (this.axMapControl2.Map.LayerCount != 0)
            {
                // 按下鼠标左键移动矩形框
                if (e.button == 1)
                {
                    IPoint pPoint = new ESRI.ArcGIS.Geometry.Point();
                    pPoint.PutCoords(e.mapX, e.mapY);
                    IEnvelope pEnvelope = this.axMapControl1.Extent;
                    pEnvelope.CenterAt(pPoint);
                    this.axMapControl1.Extent = pEnvelope;
                    this.axMapControl1.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeography, null, null);
                }
                // 按下鼠标右键绘制矩形框
                else if (e.button == 2)
                {
                    IEnvelope pEnvelop = this.axMapControl2.TrackRectangle();
                    this.axMapControl1.Extent = pEnvelop;
                    this.axMapControl1.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeography, null, null);
                }
            }
        }

 

 为鹰眼控件 MapControl2 添加 OnMouseMove 事件，主要实现按下鼠标左键的时候移动矩形框，同时也改变主的图控件的显示范围。代码如下：

 

   private void axMapControl2_OnMouseMove(object sender, IMapControlEvents2_OnMouseMoveEvent e){
            // 如果不是左键按下就直接返回
            if (e.button != 1) return;
            IPoint pPoint = new ESRI.ArcGIS.Geometry.Point();
            pPoint.PutCoords(e.mapX, e.mapY);
            this.axMapControl1.CenterAt(pPoint);
            this.axMapControl1.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeography, null, null);
    }

 

 效果:

     
 

详情参见:

http://www.gissky.net/Article/1558.htm