Engine中如何将mapSurroundFrame对象序列化为xml？

//序列化：

IMemoryBlobStream pMBStream = new MemoryBlobStreamClass();

IObjectStream pOStream = new ObjectStreamClass();

pOStream.Stream = pMBStream;

IPersistStream pPStream = (IPersistStream)mapSurroundFrame;

pPStream.Save(pOStream, 1);

pMBStream.SaveToFile(D:\\book.xml); 



//反序列化：

IObjectStream pObjectStream = new ObjectStreamClass();

IMemoryBlobStream pMemoryBlobStream = new MemoryBlobStreamClass();

pMemoryBlobStream.LoadFromFile(D:\\book.xml);

IPersistStream pPersistStream = (IPersistStream)mapSurroundFrame;

pObjectStream.Stream = pMemoryBlobStream;

pPersistStream.Load(pObjectStream); 

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