为VC6的CHtmlView继承类添加NavigateError事件响应

在VC7中CHtmlView类本身就有OnNavigateError事件响应
可是VC6中却没有, 经过一番试验, 找到以下方法为VC6增加此响应

比如CHtmlCtrl

在头文件中增加以下内容
  DECLARE_EVENTSINK_MAP()

public:
 virtual void NavigateError(LPDISPATCH pDisp, VARIANT* pvURL,
  VARIANT* pvFrame, VARIANT* pvStatusCode, VARIANT_BOOL* pvbCancel);

 virtual void OnNavigateError(LPCTSTR lpszURL, LPCTSTR lpszFrame, DWORD dwError, BOOL *pbCancel);

 在cpp文件中增加以下内容
BEGIN_EVENTSINK_MAP(CHtmlCtrl, CHtmlView)
 ON_EVENT(CHtmlCtrl, AFX_IDW_PANE_FIRST, DISPID_NAVIGATEERROR, NavigateError, VTS_DISPATCH VTS_PVARIANT VTS_PVARIANT VTS_PVARIANT VTS_PBOOL)
END_EVENTSINK_MAP()

....
void CHtmlCtrl::NavigateError(LPDISPATCH pDisp, VARIANT* pvURL,
 VARIANT* pvFrame, VARIANT* pvStatusCode, VARIANT_BOOL* pvbCancel)
{
 UNUSED_ALWAYS(pDisp);
 ASSERT(pvURL != NULL);
 ASSERT(pvFrame != NULL);
 ASSERT(pvStatusCode != NULL);
 ASSERT(pvbCancel != NULL);
 ASSERT(V_VT(pvURL) == VT_BSTR);
 ASSERT(V_VT(pvFrame) == VT_BSTR);

 CString strURL(V_BSTR(pvURL));
 CString strFrame(V_BSTR(pvFrame));
 DWORD dwError = V_I4(pvStatusCode);

 BOOL bCancel = FALSE;
 // notify the user's class
 OnNavigateError(strURL, strFrame, dwError, &bCancel);

 if (pvbCancel)
  *pvbCancel = bCancel ? AFX_OLE_TRUE : AFX_OLE_FALSE;
}

void CHtmlCtrl::OnNavigateError(LPCTSTR lpszURL, LPCTSTR lpszFrame, DWORD dwError, BOOL *pbCancel)
{
 // default to continuing
 *pbCancel = FALSE;

 // user will override to handle this notification
 UNUSED_ALWAYS(lpszURL);
 UNUSED_ALWAYS(lpszFrame);

}

这样VC6的CHtmlView继承类也就有了OnNavigateError响应方法