从网上找到一段实现了此接口的代码，可以接管IE的下载，代码如下：
public int Download(IMoniker pmk, IBindCtx pbc, uint dwBindVerb, int grfBINDF, 
            IntPtr pBindInfo, string pszHeaders, string pszRedir, uint uiCP)
        {

            // Get the display name of the pointer to an IMoniker interface that specifies
            // the object to be downloaded.
            string name = string.Empty;
            pmk.GetDisplayName(pbc, null, out name);

            if (!string.IsNullOrEmpty(name))
            {
                Uri url = null;
                bool result = Uri.TryCreate(name, UriKind.Absolute, out url);

                if (result)
                {

                    // Launch CSWebDownloader.exe to download the file. 
                    FileInfo assemblyFile =
                        new FileInfo(Assembly.GetExecutingAssembly().Location);
                    ProcessStartInfo start = new ProcessStartInfo
                    {
                        Arguments = name,
                        FileName =
                        string.Format("{0}\\CSWebDownloader.exe", assemblyFile.DirectoryName)
                    };
                    Process.Start(start);
                    return 0;
                }
            }
            return 1;
        }