[ArcEngine地图制图系列]—添加地图指北针

//添加指定样式的指北针     

  private void AddNorthArrow(IActiveView pActiveView, IEnvelope pEnv)

        {
            try
            {
                IGraphicsContainer pGraphicsContainer = pActiveView.GraphicsContainer;
                IMapFrame pMapFrame = pGraphicsContainer.FindFrame(pActiveView.FocusMap) as IMapFrame;

                IMapSurroundFrame pMapSurroundFrame = new MapSurroundFrameClass();
                pMapSurroundFrame.MapFrame = pMa