通过IWebBrowser2接口多次显示HTML时，速度会下降？（基于IE6）

Question

总的来说，这方面的问题已经在MSDN上发了多次……我本人水平不高，大家给的很多好的方案都看不明白或者不知道如何实现……整的我很无奈……前面的问题都凑合着混过去了，现在又来了……

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);

问题现象：
在这个建立的IWebBrowser2上重复显示同一个HTML面（不是刷新，就只是重复的去执行 Navigate2那段程序 ）。速度会越来越慢，比如IE6的话，一个CSS特效很多的HTML在一开始大概需要1秒加载完毕，但几百次以后会变成10秒多。这个时候如果换个简单页面显示一次，然后再加载之前的页面，速度又恢复了。如果把CSS干掉，速度确实会上升，但这个方案肯定不会通过的……
换IE7和IE8之后貌似没有问题。但是由于指定的就是IE6，所以很纠结……
至于为什么会连续几百次显示同一个页面，我只能说最终用户很SB，有这种操作的需求……
各位高人啊，有什么可以改动或者优化的地方没有？要给整崩溃了……