在MapControl绘制多边形
MapControl的OnMouseDown事件主要代码：
private void axMapControl1_OnMouseDown(object sender, ESRI.ArcGIS.Controls.IMapControlEvents2_OnMouseDownEvent e) { IGeometry pGe = axMapControl1.TrackPolygon(); IElement pElement = new PolygonElementClass() as IElement; pElement.Geometry = pGe; IGraphicsContainer GraphicsContainer = axMapControl1.Map as IGraphicsContainer; GraphicsContainer.AddElement(pElement, 0); axMapControl1.ActiveView.Refresh(); }