基于VC编写COM连接点事件的分析介绍

 [
       uuid(57CCB7A5-F3B6-4990-91CD-33A82E1AAA46),
       helpstring("IFunEvent dispinterface")
    ]
    dispinterface _IFunEvent
    {
       properties:
           //  事件接口没有任何属性
       methods:
           [id(1), helpstring("方法OnResult")] HRESULT OnResult([out,retval] LONG* retval);
           [id(2), helpstring("方法OnType")] HRESULT OnType([in] LONG nType);
}

BEGIN_SINK_MAP(CEventSink)
    SINK_ENTRY_INFO(1,DIID__INew01Events,DISPID_MSG,Msg,&MsgInfo)
END_SINK_MAP()

#pragma once

#include "ATLDemo_i.h"
#import "ATLDemo.tlb" named_guids raw_interfaces_only

class CSkin : public _IFunEvent
{
public:
    CSkin(void);
    ~CSkin(void);
private:
    DWORD       m_dwRefCount;
public:
    STDMETHODIMP Fire_OnType( LONG nType)
    {
       CString    strTemp;
       strTemp.Format(_T("The result is %d"), nType);
       AfxMessageBox(strTemp);
       return S_OK;;
    }
    HRESULT STDMETHODCALLTYPE QueryInterface(REFIID iid, void **ppvObject)
    {
       if (iid == DIID__IFunEvent)
       {
           m_dwRefCount++;
           *ppvObject = (void *)this;
           return S_OK;
       }

       if (iid == IID_IUnknown)
       {
           m_dwRefCount++;          
           *ppvObject = (void *)this;
           return S_OK;
       }

       return E_NOINTERFACE;
    }
    ULONG STDMETHODCALLTYPE AddRef()
    {
       m_dwRefCount++;
       return m_dwRefCount;
    }

    ULONG STDMETHODCALLTYPE Release()
    {
       ULONG l;

       l  = m_dwRefCount--;

       if ( 0 == m_dwRefCount)
       {
           delete this;
       }

       return l;
    }

    HRESULT STDMETHODCALLTYPE GetTypeInfoCount(
       /* [out] */ __RPC__out UINT *pctinfo)
    {
       return S_OK;
    }

    HRESULT STDMETHODCALLTYPE GetTypeInfo(
       /* [in] */ UINT iTInfo,
       /* [in] */ LCID lcid,
       /* [out] */ __RPC__deref_out_opt ITypeInfo **ppTInfo)
    {
       return S_OK;
    }

     HRESULT STDMETHODCALLTYPE GetIDsOfNames(
       /* [in] */ __RPC__in REFIID riid,
       /* [size_is][in] */ __RPC__in_ecount_full(cNames) LPOLESTR *rgszNames,
       /* [range][in] */ UINT cNames,
       /* [in] */ LCID lcid,
       /* [size_is][out] */ __RPC__out_ecount_full(cNames) DISPID *rgDispId)
    {
       return S_OK;
    }

     /* [local] */ HRESULT STDMETHODCALLTYPE Invoke(
       /* [in] */ DISPID dispIdMember,
       /* [in] */ REFIID riid,
       /* [in] */ LCID lcid,
       /* [in] */ WORD wFlags,
       /* [out][in] */ DISPPARAMS *pDispParams,
       /* [out] */ VARIANT *pVarResult,
       /* [out] */ EXCEPINFO *pExcepInfo,
       /* [out] */ UINT *puArgErr)
    {
       switch(dispIdMember) // 根据不同的dispIdMember,完成不同的回调函数，事件函数的ID编号
       {
       case 2:
           {
              // 1st param : [in] long lValue.
              VARIANT varlValue;
              long lValue = 0;
              VariantInit(&varlValue);
              VariantClear(&varlValue);
              varlValue = (pDispParams->rgvarg)[0];
              lValue = V_I4(&varlValue);
              Fire_OnType(lValue);
           }
           break;
       default:   break;
       }

       return S_OK;
    }
};

#include "StdAfx.h"
#include "Skin.h"

CSkin::CSkin(void)
{
     m_dwRefCount =0;
}

CSkin::~CSkin(void)
{
}

CoInitialize(NULL);

    CComPtr<IFun> pFun;
    HRESULT hr = pFun.CoCreateInstance(CLSID_Fun);
    if(hr!=S_OK)
    {
       return ;
    }

    IConnectionPointContainer *pCPC;
    hr = pFun->QueryInterface(IID_IConnectionPointContainer,(void **)&pCPC);
    if(!SUCCEEDED(hr))
    {
       return ;
    }
    IConnectionPoint *pCP;
    hr = pCPC->FindConnectionPoint(DIID__IFunEvent,&pCP);
    if ( !SUCCEEDED(hr) )
    {
       return ;
    }
    pCPC->Release();

    IUnknown *pSinkUnk;
    CSkin *pSink = new CSkin();
    hr = pSink->QueryInterface(IID_IUnknown,(void **)&pSinkUnk);
    DWORD dwAdvise;
    hr = pCP->Advise(pSinkUnk,&dwAdvise);//接收器与连接点建立关联

    LONG c = 0;
    pFun->Add(1,5,&c);
    //pCP->Unadvise(dwAdvise) //断开连接点事件
    pCP->Release();
    pFun.Release();

    CoUninitialize();