//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