Engine中如何将ILegend转为IElement？即实现右键选中Legend弹出的Convert To Gtaphics功能？

IPageLayout pageLayout = axPageLayoutControl1.PageLayout;

            IActiveView activeView = (IActiveView)pageLayout;

            IGraphicsContainer graphicsContainer = pageLayout as IGraphicsContainer;

            graphicsContainer.Reset();

            IElement element = graphicsContainer.Next();

            while (element != null)

            {

                if (element is IMapSurroundFrame)

                {

                    IMapSurround mapSurround = ((IMapSurroundFrame)element).MapSurround;

                    if (mapSurround is ILegend)

                    {

                        ILegend legend = (ILegend)mapSurround;

                        IGraphicsComposite graphComp = (IGraphicsComposite)legend;

                        IEnumElement enumElem = graphComp.get_Graphics(activeView.ScreenDisplay, element.Geometry.Envelope);

                        enumElem.Reset();

                        IElement ele = enumElem.Next();

                        while(ele !=null)

                        {

                            graphicsContainer.AddElement(ele,0);//可以将其添加到当前PageLayout里

                            ele = enumElem.Next();

                        }



                    }



                }

                element = graphicsContainer.Next();

            }

        }