Internet Explorer Does Not Apply an Updated Global Style Sheet Through GetHostInfo

When you specify a global style sheet by using the IDocHostUIHandler::GetHostInfo implementation in an application that hosts the Web browser control, the global style sheet cannot be changed after it has been applied the first time.

MSHTML only updates its internal global style sheet when the style sheet is first created.

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

The English version of this fix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

Microsoft has confirmed that this is a problem in Microsoft Internet Explorer 6.

This problem occurs only after MSHTML is initialized. This means that if you open a non-MSHTML document (such as a Microsoft Word document or any other type of active document server document), the next time you open an HTML file, MSHTML reinitializes the global style sheet with what is provided in the IDocHostUIHandler::GetHostInfo implementation.

Steps to Reproduce the Problem

1. In Visual Studio .NET, create a Microsoft Foundation Classes (MFC) Single Document Interface (SDI) CHtmlView application.
2. Add a member variable to the view class that will hold the current global style sheet:

   class CMFCTestView : public CHtmlView
   {
   ...
   	LPWSTR m_pZoom;
   ...
   };
   

3. Initialize the member variable to the initial style sheet that you want in the constructor:

   CMFCTestView::CMFCTestView()
   {
   	m_pZoom = L"BODY{Zoom:200%;}";
   }
   

4. Override the OnGetHostInfo virtual function of CHtmlView to implement the code to apply the global style sheet through the GetHostInfo method. IDocHostUIHandler::GetHostInfo is implemented in CHtmlControlSite and calls the method that OnGetHostInfo uses in the view.

   // header file
   class CMFCTestView : public CHtmlView
   {
   ...
   virtual HRESULT OnGetHostInfo(DOCHOSTUIINFO *pInfo);
   ...
   };
   
   // implementation file
   HRESULT CMFCTestView::OnGetHostInfo(DOCHOSTUIINFO *pInfo)
   {
   	pInfo->pchHostCss = (LPWSTR)::CoTaskMemAlloc((lstrlenW(m_pZoom)+1)*2);
   	lstrcpyW(pInfo->pchHostCss, m_pZoom);
   	return S_OK;
   }

5. Add a menu item and its handler to the CHTMLView derived class. In the menu handler, call the IWebBrowser2::Refresh() method. IWebBrowser2::Refresh() applies the new global style sheet to the active Web page.

   void CMFCTestView::OnActionTest()
   {
   	m_pZoom = L"BODY{Zoom:50%;}";
   	m_pBrowserApp->Refresh();
   }
   

6. Update the OnInitialUpdate method of the view to point to your test HTML page:

   void CMFCTestView::OnInitialUpdate()
   {
   	CHtmlView::OnInitialUpdate();
   	Navigate2(_T("http://myserver/mytestpage.htm"),NULL,NULL);
   }

7. Build and run the application. When the page is first displayed, everything appears magnified by 200 percent.
8. Use the menu action that you added to apply the new style. Without the hotfix, the page refreshes, but the magnification remains the same. After you apply the hotfix, the page refreshes and appears with the 50 percent magnification.