C# 获取Cookie

public static void GetCookie(string url) {

        Uri uri = new Uri(url);
        HttpWebRequest req = (HttpWebRequest)WebRequest.Create(uri);
        req.CookieContainer = new CookieContainer();
        req.Method = "GET";
        req.UserAgent = "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36";
        req.Headers.Add("Accept-Language", "zh-CN,zh;q=0.9");

        HttpWebResponse res = (HttpWebResponse)req.GetResponse();
        var cookies_str = req.CookieContainer.GetCookieHeader(req.RequestUri);
        var cookies = req.CookieContainer;


        var myReq = (HttpWebRequest)WebRequest.Create(url);
        myReq.Timeout = 20 * 1000; //连接超时  
        myReq.Accept = "*/*";
        myReq.UserAgent = "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36";
        myReq.CookieContainer = cookies; //使用已经保存的cookies 方法一</span>  
        //myHttpWebRequest.Headers.Add("Cookie", cookiesstr); //使用已经保存的cookies 方法二  
        HttpWebResponse myHttpWebResponse = (HttpWebResponse)myReq.GetResponse();
        Stream stream = myHttpWebResponse.GetResponseStream();
        stream.ReadTimeout = 15 * 1000; //读取超时  
        StreamReader sr = new StreamReader(stream, Encoding.GetEncoding("GB2312"));
        string strWebData = sr.ReadToEnd();

    }