ArcGis实现画矩形（RectangleFeedBack）

private void axMapControl1_OnMouseDown(object sender, IMapControlEvents2_OnMouseDownEvent e)
        {
            IPoint pPoint = new PointClass();
            pPoint.PutCoords(e.mapX, e.mapY);

            pFeedBack = new NewEnvelopeFeedbackClass();
            pFeedBack.Display = axMapControl1.ActiveView.ScreenDisplay;
            pFeedBack.Start(pPoint);
        }

        private void axMapControl1_OnMouseMove(object sender, IMapControlEvents2_OnMouseMoveEvent e)
        {
            IPoint pPoint = new PointClass();
            pPoint.PutCoords(e.mapX, e.mapY);
            pFeedBack.MoveTo(pPoint);
        }

        private void axMapControl1_OnMouseUp(object sender, IMapControlEvents2_OnMouseUpEvent e)
        {
            IGeometry pGeometry;
            pGeometry = pFeedBack.Stop();
            pFeedBack = null;
            IActiveView pActiveView = axMapControl1.ActiveView;
           
            AddRectangle(pGeometry, pActiveView);
        }
        private void AddRectangle(IGeometry pGeometry, IActiveView pActiveView)
        {

            ISimpleLineSymbol pSimpleLineSymbol = new SimpleLineSymbolClass();
            pSimpleLineSymbol.Color = GetRGBColor(255, 215, 0);
            pSimpleLineSymbol.Style = esriSimpleLineStyle.esriSLSDash;
            pSimpleLineSymbol.Width = 2;
          

            ISimpleFillSymbol pSimpleFillSymbol = new SimpleFillSymbolClass();
            pSimpleFillSymbol.Color = GetRGBColor(0, 80, 30);
            pSimpleFillSymbol.Outline = pSimpleLineSymbol;
            pSimpleFillSymbol.Style = esriSimpleFillStyle.esriSFSSolid;

            IElement pElement;
            pElement = new RectangleElementClass();
             pElement.Geometry = pGeometry;//同画圆不同，这里直接引用的pGeometry

            IFillShapeElement pFillShapeElement;
            pFillShapeElement = pElement as IFillShapeElement;
            pFillShapeElement.Symbol = pSimpleFillSymbol;

            IGraphicsContainer pGraphicsContainer = axMapControl1.ActiveView as IGraphicsContainer;
            pGraphicsContainer.AddElement((IElement)pFillShapeElement, 0);
            axMapControl1.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGraphics, null, null);
        }
        private IRgbColor GetRGBColor(int red, int green, int blue)
        {
            IRgbColor rGBColor = new RgbColorClass();
            rGBColor.Red = red;
            rGBColor.Green = green;
            rGBColor.Blue = blue;
            return rGBColor;
        }