callback.h

opc的客户端程序,在csdn上下的,不过我想看看这里下的详细说明

//---------------------------------------------------------
// OPC Custom 2.0 Sample
// Asynchronous IO with MFC and ATL
// (c) Siemens AG 2000
//---------------------------------------------------------

//
// Callback.h : Declaration of callback class and definition of minor methods
//
//#include "..\SendAgent.h" 
//#include "..\publicdata\DataBase.H"
extern CComModule _Module;
#include <atlcom.h>

class COPCDataCallback :
public CComObjectRoot,
	public IOPCDataCallback
{

public:
COPCDataCallback() {};
~COPCDataCallback() {};

BEGIN_COM_MAP(COPCDataCallback)
	COM_INTERFACE_ENTRY(IOPCDataCallback)
END_COM_MAP()

// IOPCDataCallback 
	STDMETHODIMP  OnDataChange( 
            /* [in] */ DWORD dwTransid,
            /* [in] */ OPCHANDLE hGroup,
            /* [in] */ HRESULT hrMasterquality,
            /* [in] */ HRESULT hrMastererror,
            /* [in] */ DWORD dwCount,
            /* [size_is][in] */ OPCHANDLE __RPC_FAR *phClientItems,
            /* [size_is][in] */ VARIANT __RPC_FAR *pvValues,
            /* [size_is][in] */ WORD __RPC_FAR *pwQualities,
            /* [size_is][in] */ FILETIME __RPC_FAR *pftTimeStamps,
            /* [size_is][in] */ HRESULT __RPC_FAR *pErrors);


    STDMETHODIMP  OnReadComplete( 
            /* [in] */ DWORD dwTransid,
            /* [in] */ OPCHANDLE hGroup,
            /* [in] */ HRESULT hrMasterquality,
            /* [in] */ HRESULT hrMastererror,
            /* [in] */ DWORD dwCount,
            /* [size_is][in] */ OPCHANDLE __RPC_FAR *phClientItems,
            /* [size_is][in] */ VARIANT __RPC_FAR *pvValues,
            /* [size_is][in] */ WORD __RPC_FAR *pwQualities,
            /* [size_is][in] */ FILETIME __RPC_FAR *pftTimeStamps,
            /* [size_is][in] */ HRESULT __RPC_FAR *pErrors);
		

        
        STDMETHODIMP  OnWriteComplete( 
            /* [in] */ DWORD dwTransid,
            /* [in] */ OPCHANDLE hGroup,
            /* [in] */ HRESULT hrMastererr,
            /* [in] */ DWORD dwCount,
            /* [size_is][in] */ OPCHANDLE __RPC_FAR *pClienthandles,
            /* [size_is][in] */ HRESULT __RPC_FAR *pErrors);

        
        STDMETHODIMP  OnCancelComplete( 
            /* [in] */ DWORD dwTransid,
            /* [in] */ OPCHANDLE hGroup) 
		{
			return S_OK;
		};
};