slikserverevents.cpp

一个OPC 服务器程序

// SLIKServerEvents.cpp: implementation of the CSLIKServerEvents class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "SLIKServerEvents.h"

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CSLIKServerEvents::CSLIKServerEvents()
{
}

CSLIKServerEvents::~CSLIKServerEvents()
{
}


//////////////////////////////////////////////////////////////////////
// Event Handlers
//////////////////////////////////////////////////////////////////////

HRESULT __stdcall CSLIKServerEvents::OnClientConnectHandler(
    long			lNumClients,
    VARIANT_BOOL	*pbAcceptConnection 
	)
{
	//
	//	We'll accept any connection that DCOM security accepts
	//
	*pbAcceptConnection = VARIANT_TRUE;
	return S_OK;
}


HRESULT __stdcall CSLIKServerEvents::OnClientDisconnectHandler(
    long			lNumClients
	)
{
	//
	//	We can shut down if there are no longer any connected clients
	//
	if( lNumClients == 0 )
		PostThreadMessage( GetCurrentThreadId(), WM_QUIT, 0, 0 );
	return S_OK;
}


HRESULT __stdcall CSLIKServerEvents::OnReadHandler(
	long			lCount, 
	SAFEARRAY		**ppsaTags,			// ptr to safe array of ISLIKTag *
	SAFEARRAY		**ppsaAccessPaths,	// ptr to safe array of BSTR 
	SAFEARRAY		**ppsaErrors,		// ptr to safe array of long
	long			*plResult
	)
{
	HRESULT hr = S_OK;

	try
	{
		*plResult = S_OK;

		//	
		//	In this implementation, we assume that the data simulation
		//	already has provided the most up to date data.  So, we just
		//	update the output parameters, as required.
		//
		//	NOTE: All safe arrays from SLIK-DA events are 0-based
		//
		for( long i = 0; i < lCount; i++ )
		{
			long lError = S_OK;
			_com_util::CheckError( SafeArrayPutElement( *ppsaErrors, &i, &lError ) );
		}
		*plResult = S_OK;
	}
	catch( _com_error e )
	{
		hr = e.Error();
	}

	return hr;
}


HRESULT __stdcall CSLIKServerEvents::OnWriteHandler(
	long			lCount, 
	SAFEARRAY		**ppsaTags,			// ptr to safe array of ISLIKTag *
	SAFEARRAY		**ppsaAccessPaths,	// ptr to safe array of BSTR
	SAFEARRAY		**ppsaValues,		// ptr to safe array of VARIANT
	SAFEARRAY		**ppsaErrors,		// ptr to safe array of long
	long			*plResult
	)
{
	HRESULT hr = S_OK;

	try
	{
		*plResult = S_OK;

		//
		//	This SIMPLE implementation just copies the given value to the
		//	corresponding tag.  A REAL implementation would typically be 
		//	more rigorous here with respect to range checking, etc.
		//
		//	NOTE: All safe arrays from SLIK-DA events are 0-based
		//
		for( long i = 0; i < lCount; i++ )
		{
			VARIANT vVal;
			_com_util::CheckError( SafeArrayGetElement( *ppsaValues, &i, &vVal ) );

			CComPtr<ISLIKTag> spTag;
			_com_util::CheckError( SafeArrayGetElement( *ppsaTags, &i, &spTag ) );

			long lError = spTag->SetVQT( vVal, sdaGood, 0 );
			_com_util::CheckError( SafeArrayPutElement( *ppsaErrors, &i, &lError ) );

			if( FAILED( lError ) )
				*plResult = S_FALSE;
		}
	}
	catch( _com_error e )
	{
		hr = e.Error();
	}

	return hr;
}