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();