WebBrowser控件中如何使用cookie的CookieContainer？

var webRequest =(HttpWebRequest)WebRequest.Create(@"url");

            webRequest.CookieContainer=newCookieContainer();var response =(HttpWebResponse)webRequest.GetResponse();

            webBrowser1.DocumentStream= response.GetResponseStream();var cookieBuilder =newStringBuilder();foreach(var cookie in response.Cookies){

                cookieBuilder.Append(cookie.ToString()).Append(";");}

            webBrowser1.Document.Cookie= cookieBuilder.ToString();