1、MapControl的CurrentTool=null不起作用：
   在VB中使用MapControl.CurrentTool=nothing即可，而使用C#就不灵了。解决办法如下所示，先做一转换即可。
    IMapControl2 pMainMap2=(IMapControl2)axMapMain.Object;
    pMainMap2.CurrentTool=null;

2、TocControl的HitTest不起作用：
该问题与上一问题类似，做以下处理
   ITOCControl pTOCControl = (ITOCControl)axTOCCtrl.Object;
   pTOCControl.HitTest(e.x, e.y, ref item, ref map, ref layer, ref other, ref index);

3、通过TocControl 控件的事件调换图层：

  ILayer pMoveLayer; 
  int iToLayerIndex;
  private void axTOCCtrl_OnMouseDown(object sender, AxESRI.ArcGIS.TOCControl.ITOCControlEvents_OnMouseDownEvent e){
   esriTOCControlItem item = esriTOCControlItem.esriTOCControlItemNone;
   IBasicMap map = null;
   ILayer layer = null;
   object other = null;
   object index = null;
   ITOCControl pTOCControl = (ITOCControl)axTOCCtrl.Object;
   pTOCControl.HitTest(e.x, e.y, ref item, ref map, ref layer, ref other, ref index);
   axMapMain.CustomProperty = layer;
   if(e.button==1){
    if(item==esriTOCControlItem.esriTOCControlItemLayer){
     if(layer is IAnnotationSublayer) {
      return;
     }
     else {
      pMoveLayer=layer;
     }
     axTOCCtrl.MousePointer=esriControlsMousePointer.esriPointerHotLink;
    }
   }

      }
      pMap.MoveLayer(pMoveLayer,iToLayerIndex);
      axMapMain.ActiveView.Refresh();
     }
    }
    axTOCCtrl.MousePointer=esriControlsMousePointer.esriPointerArrow;
   }  
  }

4、鹰眼的实现
  private void drawMapEagleRect(IMap pMap, int iRed, int iGreen, int iBlue, int iWidth, object newEnvelope){
   IEnvelope pNewMainEnv = (IEnvelope)newEnvelope;

   pActiveView.PartialRefresh(esriViewDrawPhase.esriViewGraphics, null, null);    
  } 

  private void axMapMain_OnMapReplaced(object sender, AxESRI.ArcGIS.MapControl.IMapControlEvents2_OnMapReplacedEvent e) {
   if(!axMapMain.DocumentFilename.Equals("")){
    axMapEagle.LoadMxFile(axMapMain.DocumentFilename);
    axMapEagle.Extent=axMapEagle.FullExtent;
    drawMapEagleRect(axMapEagle.Map,255,0,0,1,axMapMain.Extent.Envelope);
   }
  }

  private void axMapEagle_OnMouseDown(object sender, AxESRI.ArcGIS.MapControl.IMapControlEvents2_OnMouseDownEvent e) {
   IPoint pPoint=new PointClass();
   pPoint.PutCoords(e.mapX,e.mapY);
   axMapMain.CenterAt(pPoint);
  }

T.B.D.