程序是这样：
标准C++，没有使用MFC
使用IWebBrowser2进行一个HTML文件的显示，由于CSS特效很多，所以加载时间有可能长达3-4秒。为保证不会出现白屏或者之前页面的残存，需要判断是否加载完毕，如果加载完毕，则会用SetWindowPos将窗体显示出来。
代码如下：
建立窗体
m_hWeb = CreateWindowEx(
WS_EX_TOOLWINDOW,
"AtlAxWin90",
"Shell.Explorer.2",
WS_POPUP | WS_VISIBLE ,
m_nLeft,
m_nTop,
m_nWidth,
m_nHeight,
NULL,
NULL,
NULL,
NULL
);
获取IWebBrowser2
CComQIPtr<IWebBrowser2> m_pIE;
lAtlRet = AtlAxGetControl(m_hWeb, &pDef);
if (lAtlRet != S_OK)
{
return FALSE;
}
m_pIE = pDef;
if (m_pIE == NULL)
{
return FALSE;
}
实现IDispatch接口
interface IWebEvent : public IDispatch
{
public:
HANDLE m_hEventHandle;
IDispatch* m_IDispatch;
void setIDispatch(IDispatch* IDispatch)
{
m_IDispatch = IDispatch;
}
void setHandle(HANDLE handle)
{
m_hEventHandle = handle;
}
//IDispatch
HRESULT STDMETHODCALLTYPE QueryInterface(REFIID iid, void ** ppvObject)
{
if(IsEqualIID(iid, IID_IUnknown)||
IsEqualIID(iid, IID_IDispatch)||
IsEqualIID(iid, DIID_DWebBrowserEvents2))
{
*ppvObject = this;
}
else
{
*ppvObject = NULL;
return E_NOINTERFACE;
}
return S_OK;
}
ULONG STDMETHODCALLTYPE AddRef(void)
{
return 1;
}
ULONG STDMETHODCALLTYPE Release(void)
{
return 0;
}
HRESULT STDMETHODCALLTYPE GetTypeInfo(unsigned int iTInfo, LCID lcid, ITypeInfo FAR* FAR* ppTInfo)
{
if (ppTInfo == NULL)
{
return E_INVALIDARG;
}
*ppTInfo = NULL;
if(iTInfo != 0)
{
return DISP_E_BADINDEX;
}
return S_OK;
}
HRESULT STDMETHODCALLTYPE GetTypeInfoCount(unsigned int FAR* pctinfo)
{
return E_NOTIMPL;
}
HRESULT STDMETHODCALLTYPE GetIDsOfNames(REFIID riid, OLECHAR FAR* FAR* rgszNames, unsigned int cNames, LCID lcid, DISPID FAR* rgDispId)
{
return E_NOTIMPL;
}
HRESULT STDMETHODCALLTYPE Invoke(DISPID dispIdMember, REFIID riid, LCID lcid, WORD wFlags, DISPPARAMS FAR* pDispParams, VARIANT FAR* pVarResult, EXCEPINFO FAR* pExcepInfo, unsigned int FAR* puArgErr)
{
switch(dispIdMember)
{
case DISPID_DOCUMENTCOMPLETE://DocumentComplete
char buff[256];
memset(buff,0,256);
wcstombs(buff,pDispParams->rgvarg[0].pvarVal->bstrVal,256);
if (m_IDispatch == (IDispatch*)pDispParams->rgvarg[1].ppdispVal)
{
SetEvent(m_hEventHandle);
}
break;
default:
break;
}
return S_OK;
}
};
设置链接点
m_hDocComplete = CreateEvent(NULL, FALSE, FALSE, NULL);
m_cWebEvent = new IWebEvent();
m_cWebEvent->QueryInterface(IID_IDispatch, (void **)&m_cWebEvent);
m_cWebEvent->setHandle(m_hDocComplete);
IConnectionPointContainer *spCPC;
hRet = m_pIE->QueryInterface(IID_IConnectionPointContainer,(void**)&spCPC);
if(FAILED(hRet))
{
MessageBox(NULL, "m_pIE->QueryInterface", "m_pIE->QueryInterface", NULL);
}
IConnectionPoint *spCP;
hRet = spCPC->FindConnectionPoint(DIID_DWebBrowserEvents2,&spCP);
if(FAILED(hRet))
{
MessageBox(NULL, "spCPC->FindConnectionPoint", "spCPC->FindConnectionPoint", NULL);
}
DWORD cookie;
hRet = spCP->Advise(m_cWebEvent, &cookie);
if(FAILED(hRet))
{
MessageBox(NULL, "spCP->Advise", "spCP->Advise", NULL);
}
m_pIE->QueryInterface(IID_IDispatch,(void**)&lpWBDisp);
m_cWebEvent->setIDispatch(lpWBDisp);
等待DOCUMENTCOMPLETE事件中设置的EVENT
CComVariant vUrl(chHtmlFileNameBuffer);
CComVariant vEmpty;
hRet = m_pIE->put_Visible(VARIANT_TRUE);
if (hRet != S_OK)
{
return FALSE;
}
hRet = m_pIE->Navigate2(&vUrl, &vEmpty, &vEmpty, &vEmpty, &vEmpty);
if (hRet != S_OK)
{
return FALSE;
}
if (g_hTopMost == m_hWeb)
{
return TRUE;
}
WaitForSingleObject(m_hDocComplete, INFINITE);
现在问题是整个程序是靠主线程中MessageLoop进行控制，用GetMessage接到Message后，调用相应的处理。
如果m_pIE->Navigate2和 WaitForSingleObject在主线程中调用的话，在WaitForSingleObject就开始等待DOCUMENTCOMPLETE了。 但此时MessageLoop是停止的，m_pIE->Navigate2也没有继续进行（此为推测，因为一直没有进入响应 DOCUMENTCOMPLETE的代码）
如果开一个线程，将m_pIE->Navigate2和WaitForSingleObject在新线程中做，程序正常。
但是多开一个线程，就有可能埋藏一些隐含问题，不知道现在使用的这些东西有没有线程安全的隐患。
或者有高手知道在一个线程上即能实现等待DOCUMENTCOMPLETE而且MessageLoop也能正常进行的方法么？
之前在这里发过相关问题，如果这个帖子看不太明白，可以参照：
http://social.microsoft.com/Forums/zh-CN/visualcpluszhchs/thread/141fb967-b54e-43ea-9697-ffea5d49f8fc
