private void Form1_Load(object sender, EventArgs e)
        {

            this.webBrowser1.Navigating += new WebBrowserNavigatingEventHandler(webBrowser1_Navigating);
        }

        void webBrowser1_Navigating(object sender, WebBrowserNavigatingEventArgs e)
        {
            MessageBox.Show(e.Url);
        }

------解决方案--------------------

private void BrowserEx_DocumentCompleted(object   sender,WebBrowserDocumentCompletedEventArgs e)
       {
           MessageBox.Show(e.Url.ToString());


       }