HOWTO: Get WinInet Information from a URL Moniker Binding

• Microsoft ActiveX SDK, version 1.0
• Internet Client SDK, versions 4.0, 4.01

SUMMARY

Programs that use URL Monikers to download data but need to obtain extra low-level WinInet information about the download can use the IWinInetHttpInfo and IWinInetInfo interfaces.

The IWinInetHttpInfo interface implemented by the binding object can be used to make the equivalent of HttpQueryInfo calls. In the same fashion, IWinInetInfo can be used to make the equivalent of InternetQueryOption calls.

MORE INFORMATION

The user of a URL Moniker receives a reference to the IBinding interface of the binding object in the IBindStatusCallback::OnStartBinding interface. When binding to an HTTP server, the binding object supports the IWinInetHttpInfo interface for obtaining HTTP-specific information, such as HTTP headers. The binding object also supports the IWinInetInfo interface for obtaining Internet options such as the name of the file downloaded by a URL moniker binding. Both interfaces support the QueryInfo method. QueryInfo basically forwards the call to the standard WinInet functions HttpQueryInfo and InternetQueryOption, respectively.

Here is a sample snippet of code from an IBindStatusCallback implementation that uses IWininetHttpInfo to retrieve the raw headers sent by the HTTP server. It then uses IWininetInfo to query for the name of the local data file returned by the download:

   // required includes:
   #include <urlmon.h>
   #include <wininet.h>

   STDMETHOD(OnStopBinding)(HRESULT hresult, LPCWSTR szError)
   {
      // m_spBinding is the IBinding interface passed in OnStartBinding

      if (!FAILED(hresult))
      {
         IWinInetHttpInfo* pInfo;
         char buff[1024];
         DWORD dwBuffSize = 1024;
         HRESULT hr = m_spBinding->QueryInterface(IID_IWinInetHttpInfo,
                                                  (void**)&pInfo);
         if (!FAILED(hr))
         {
            BOOL bResult = pInfo->QueryInfo(HTTP_QUERY_RAW_HEADERS,
                                            buff, &dwBuffSize, 0, NULL);
         }
         pInfo->Release();
      }

      if (!FAILED(hresult))
      {
         IWinInetInfo* pInfo;
         char buff[1024];
         DWORD dwBuffSize = 1024;
         HRESULT hr = m_spBinding->QueryInterface(IID_IWinInetInfo,
                                                  (void**)&pInfo);
         if (!FAILED(hr))
         {
            BOOL bResult = pInfo
            ->QueryOption(INTERNET_OPTION_DATAFILE_NAME,
                                             buff, &dwBuffSize);
         }
         pInfo->Release();
      }

   // ...
   return S_OK;
   }

REFERENCES

Internet Client SDK: Internet Tools & Technologies; Monikers, URLs, Security Zones, and Pluggable Protocols

Internet Client SDK: Internet Tools & Technologies; WinInet API

Keywords          : AXSDKUrlMon kbcode
Technology        : kbInetDev
Version           : WINDOWS:1.0,4.0,4.01
Platform          : WINDOWS
Issue type        : kbhowto