AciveX接口事件的手动实现

为了理解ActiveX事件的运作原理，特意做了如下实验

初试化过程：

try

{

  CLSID clsid;

  HRESULT hr=::CLSIDFromProgID(L"MSWinsock.Winsock",&clsid);

  if(FAILED(hr))

   throw "获得对象的CLSID失败";

  hr=::CoCreateInstance(clsid,NULL,CLSCTX_INPROC_SERVER,__uuidof(IMSWinsockControl),(void**)&pMSWinsockControl);

  if(FAILED(hr))

   throw "创建对象失败...";

  hr=pMSWinsockControl->put_Protocol(sckUDPProtocol);

  if(FAILED(hr))

   throw "设置协议类型失败...";

  IConnectionPoint *cp=NULL;

  SinkDMSWinsockControlEvents * TheEventSink=NULL;

  IConnectionPointContainer *cps=NULL;

  hr=pMSWinsockControl->QueryInterface(IID_IConnectionPointContainer,(void**)&cps);

  if(FAILED(hr))

   throw "查询事件容器失败...";

  hr=cps->FindConnectionPoint(__uuidof(DMSWinsockControlEvents),&cp);

  if(FAILED(hr))

   throw "查找连接点失败...";

  cps->Release();

  hr=cp->Advise(&TheEventSink,&ConnectPointCookie);

  if(FAILED(hr))

   throw "连接连接点失败...";

  cp->Release();

}

catch(char* msg)

{

  MessageBox(CString(msg));

  return S_FALSE;

}

return S_OK;

}

事件的实现类：

class SinkDMSWinsockControlEvents : public IDispatch

{

。。。。。。

//DISPID是一个长整数，它标识的是一个函数。对于IDispatch的某一个特定的实现，DISPID都是唯一的。IDispatch的每一个实现都有其自己的IID,这里dispidMemeber实际上是可以认为是和IE实例所发生的每一个事件相关的方法，比如：DISPID_BEFORENAVIGATE2，DISPID_NAVIGATECOMPLETE2

STDMETHODIMP Invoke(

DISPID dispID,

REFIID riid,

LCID lcid,

WORD wFlags,

DISPPARAMS * pdispparams,

VARIANT * pvarResult,

EXCEPINFO * pexcepinfo,

UINT * puArgErr)

{

int i;

switch(dispID)

{

case :

  OnDataArrive(pdispparams->rgvarg->intVal);

  break;

default: break;

}

return S_OK;

}

void SinkDMSWinsockControlEvents::OnDataArrive(long bytesTotal)

{

VARIANT vtData;

vtData.vt=VT_BSTR;

    vtData.bstrVal=CString("").AllocSysString();

    pMSWinsockControl->GetData(&vtData);

CString str(vtData.bstrVal);

pCommunucationCtrl->m_CurrentCommand=vtData.bstrVal;

pCommunucationCtrl->Fire_OnCommandComming(vtData.bstrVal);

}

}

看起来复杂的东西就是这样