void ieInstance_DocumentComplete(object pDisp, ref object URL)
        {
            string url = URL as string;

            if (string.IsNullOrEmpty(url) 
                || url.Equals("about:blank", StringComparison.OrdinalIgnoreCase))
            {
                return;
            }

            InternetExplorer explorer = pDisp as InternetExplorer;

            // Set the handler of the document in InternetExplorer.
            if (explorer != null)
            {
                MessageBox.Show(url);//这句是我加的
                SetHandler(explorer);
            }
        }