isshelper.h

这是一个采用OLE DB编程处理的上传BLOB类型的二进制数据到数据库的一个实例

// ISSHelper.h: interface for the CISSHelper class.
//
//////////////////////////////////////////////////////////////////////

#if !defined(AFX_ISSHELPER_H__7B88E5F3_263F_11D2_9D1F_00C04F96B8B2__INCLUDED_)
#define AFX_ISSHELPER_H__7B88E5F3_263F_11D2_9D1F_00C04F96B8B2__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

class CISSHelper : public ISequentialStream  
{
public:

	// Constructor/destructor.
	CISSHelper();
	virtual ~CISSHelper();

	// Helper function to clean up memory.
	virtual void Clear();

	// ISequentialStream interface implementation.
	STDMETHODIMP_(ULONG)	AddRef(void);
	STDMETHODIMP_(ULONG)	Release(void);
	STDMETHODIMP QueryInterface(REFIID riid, LPVOID *ppv);
    STDMETHODIMP Read( 
            /* [out] */ void __RPC_FAR *pv,
            /* [in] */ ULONG cb,
            /* [out] */ ULONG __RPC_FAR *pcbRead);
    STDMETHODIMP Write( 
            /* [in] */ const void __RPC_FAR *pv,
            /* [in] */ ULONG cb,
            /* [out] */ ULONG __RPC_FAR *pcbWritten);

public:

	void*       m_pBuffer;		// Buffer
	ULONG       m_ulLength;     // Total buffer size.
	ULONG       m_ulStatus;     // Column status.

private:

	ULONG		m_cRef;			// Reference count (not used).
	ULONG       m_iReadPos;     // Current index position for reading from the buffer.
	ULONG       m_iWritePos;    // Current index position for writing to the buffer.

};


#endif // !defined(AFX_ISSHELPER_H__7B88E5F3_263F_11D2_9D1F_00C04F96B8B2__INCLUDED_)