Arcgis Engine - 鹰眼(减少闪烁)

　　网上看到的代码,都是一个模样,经过不断调试,无意中效果就可以了.主要是在"鼠标拖动的时候",网上的代码的鹰眼效果,感觉坑爹死了,闪烁超级严重.主要原因是鼠标拖动的时候,进行时时更新.(该博文的鹰眼可能针对栅格图不起作用,可以参考我的这篇博文(arcgis engine - 鹰眼在栅格图无法显示.)

　　我在"天地图"上,它实现的效果也是鼠标拖动放开后才更新.以下是我对网上的代码进行稍微的改动:

　　主视图:

#region 主视图事件.

//同步鹰眼视图和主视图.

private void map_main_OnMapReplaced(object sender, ESRI.ArcGIS.Controls.IMapControlEvents2_OnMapReplacedEvent e) {

    mapCtrl_view.ClearLayers();

    for (int i = 0; i < mapCtrl_main.LayerCount; i++) mapCtrl_view.AddLayer(mapCtrl_main.get_Layer(i));

    mapCtrl_view.Extent = mapCtrl_main.FullExtent;

    mapCtrl_main.Refresh();

}

//画轮廓.

private void map_main_OnExtentUpdated(object sender, ESRI.ArcGIS.Controls.IMapControlEvents2_OnExtentUpdatedEvent e) {

    DrawSymbol(sender, (ESRI.ArcGIS.Geometry.IEnvelope)e.newEnvelope);

}

#endregion

　　 辅助方法:

 /// <summary>

         /// 返回颜色.

         /// </summary>

         /// <param name="rgb">rgb的值</param>

         /// <param name="transparency">透明度[0,255](0为全透明)</param>

         /// <returns>颜色对象.</returns>

         ESRI.ArcGIS.Display.IRgbColor ColorPaint(int rgb, byte transparency) {

             ESRI.ArcGIS.Display.IRgbColor rgbColor = new ESRI.ArcGIS.Display.RgbColorClass();

             rgbColor.RGB = rgb;

             rgbColor.Transparency = transparency;

             return rgbColor;

         }

         /// <summary>

         /// 画轮廓.

         /// </summary>

         /// <param name="sender"></param>

         /// <param name="e">根据IEnvelope对象画轮廓.</param>

         void DrawSymbol(object sender, ESRI.ArcGIS.Geometry.IEnvelope e) {

             ESRI.ArcGIS.Carto.IGraphicsContainer hawkGC = (ESRI.ArcGIS.Carto.IGraphicsContainer)mapCtrl_view.Map;

             ESRI.ArcGIS.Carto.IActiveView aView = (ESRI.ArcGIS.Carto.IActiveView)hawkGC;

             hawkGC.DeleteAllElements();

             ESRI.ArcGIS.Carto.IElement recEle = (ESRI.ArcGIS.Carto.IElement)new ESRI.ArcGIS.Carto.RectangleElementClass();

             recEle.Geometry = e;

             ESRI.ArcGIS.Display.ISimpleLineSymbol outLine = new ESRI.ArcGIS.Display.SimpleLineSymbolClass();

             outLine.Color = ColorPaint(, );

             outLine.Width = ;

             //填充样式.

             ESRI.ArcGIS.Display.ISimpleFillSymbol fillSym = new ESRI.ArcGIS.Display.SimpleFillSymbolClass();

             fillSym.Color = ColorPaint(, );

             fillSym.Outline = outLine;

             ESRI.ArcGIS.Carto.IFillShapeElement fillShape = (ESRI.ArcGIS.Carto.IFillShapeElement)recEle;

             fillShape.Symbol = fillSym;

             hawkGC.AddElement((ESRI.ArcGIS.Carto.IElement)fillShape, );

             aView.PartialRefresh(ESRI.ArcGIS.Carto.esriViewDrawPhase.esriViewGraphics, null, null);

         }

　　鹰眼视图:

 #region 鹰眼事件.

 private void map_view_OnMouseDown(object sender, ESRI.ArcGIS.Controls.IMapControlEvents2_OnMouseDownEvent e) {

     if (mapCtrl_main.LayerCount < ) return;

     if (e.button == ) { //点选.

     ESRI.ArcGIS.Geometry.IPoint ptNew = new ESRI.ArcGIS.Geometry.PointClass();

     ptNew.PutCoords(e.mapX, e.mapY);

     }

     else if (e.button == ) //右键框选.

     {

     interEnvelope = mapCtrl_view.TrackRectangle();

     //记录感兴趣区.

     mapCtrl_main.Extent = interEnvelope;

     }

     mapCtrl_main.ActiveView.PartialRefresh(ESRI.ArcGIS.Carto.esriViewDrawPhase.esriViewGeography, null, null);

 }

 private void map_view_OnMouseMove(object sender, ESRI.ArcGIS.Controls.IMapControlEvents2_OnMouseMoveEvent e) {

     if (e.button ==  && interEnvelope != null) {

     //鼠标移动,轮廓跟着变,但是主视图不更新,直到鼠标放开.

     interEnvelope.PutCoords(e.mapX - interEnvelope.Width / , e.mapY - interEnvelope.Height / , e.mapX + interEnvelope.Width / , e.mapY + interEnvelope.Height / );

     DrawSymbol(sender, interEnvelope);

     }

 }

 private void map_view_OnMouseUp(object sender, ESRI.ArcGIS.Controls.IMapControlEvents2_OnMouseUpEvent e) {

     //鼠标放开时同步更新主视图,和map_view_OnMouseMove搭配.

     ESRI.ArcGIS.Geometry.IPoint ptNew = new ESRI.ArcGIS.Geometry.PointClass();

     ptNew.PutCoords(e.mapX, e.mapY);

     mapCtrl_main.CenterAt(ptNew);

     mapCtrl_main.ActiveView.PartialRefresh(ESRI.ArcGIS.Carto.esriViewDrawPhase.esriViewGeography, null, null);

 }

 #endregion