.net 获取httpwenresponse 返回的cookie！！

[qq_34378352]

#region

public static CookieContainer CookieContainer { get; set; }

#endregion

private void GetJSESSIONID()
{
HttpWebRequest request = null;
HttpWebResponse response = null;
try
{
string post_data = "name=-----%password=*****";
string Url = "http://service2.swu.edu.cn/selfservice/module/scgroup/web/login_judge.jsf";
request = (HttpWebRequest) WebRequest.Create(Url);

request.Method = "POST";
request.Host = "service2.swu.edu.cn";
request.KeepAlive = true;
request.Headers.Add("Cache-Control: max-age=0");
request.Headers.Add("Origin: http://service2.swu.edu.cn");
request.Headers.Add("Upgrade-Insecure-Requests: 1");
request.UserAgent = "Mozilla/5.0 (Windows NT 6.3; WOW64)";
request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8";
request.Referer = "http://service2.swu.edu.cn/selfservice/module/scgroup/web/login_self.jsf";
request.Headers.Add("Accept-Encoding: gzip, deflate, sdch");
request.Headers.Add("Accept-Language: zh-CN,zh;q=0.8");
request.Headers.Add("DNT: 1");

Stream RequestStream = request.GetRequestStream();
StreamWriter StreamWriter = new StreamWriter(RequestStream);
StreamWriter.Write(post_data);
StreamWriter.Close();

CookieContainer = null; //请问这里的代码有问题吗？在MSDN上看得一知半解的。求教！
response = (HttpWebResponse) request.GetResponse();
CookieCollection cookies = response.Cookies;
CookieContainer.Add(cookies); //运行的时候说“未将对象引用设置到对象的实例。”但是这个网站是返回cookie的。

request.Abort();
response.Close();
StreamWriter.Close();

//if (CookieContainer != null)
//{
// request.CookieContainer = CookieContainer;
//}
//else
//{
// request.CookieContainer = new CookieContainer();
// CookieContainer = request.CookieContainer;
//}
}
catch (WebException ex)
{
MessageBox.Show(ex.Message);
}
}

private void PostLogout(object sender, RoutedEventArgs e)
{
GetJSESSIONID();
HttpWebRequest request = null;
HttpWebResponse response = null;
try
{
string Url = "http://service2.swu.edu.cn/selfservice/module/webcontent/web/onlinedevice_list.jsf";
request = (HttpWebRequest) WebRequest.Create(Url);

request.Method = "GET";
request.CookieContainer = CookieContainer;
request.Host = "service2.swu.edu.cn";
request.KeepAlive = true;
request.Headers.Add("Upgrade-Insecure-Requests: 1");
request.UserAgent = "Mozilla/5.0 (Windows NT 6.3; WOW64)";
request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8";
request.Headers.Add("Accept-Encoding: gzip, deflate, sdch");
request.Headers.Add("Accept-Language: zh-CN,zh;q=0.8");
request.Headers.Add("DNT: 1");

response = (HttpWebResponse)request.GetResponse();

Stream ResponseStream = response.GetResponseStream();
StreamReader StreamReader = new StreamReader(ResponseStream);
string retString = StreamReader.ReadToEnd();

request.Abort();
response.Close();
StreamReader.Close();

textBox1.AppendText(retString);
}
catch (WebException ex)
{
MessageBox.Show(ex.Message, string.Format("出错"));
}
}