C# 使用HttpWebRequest和HttpWebResponse进行设置和获取Cookie

使用HttpWebRequest和HttpWebResponse进行设置和获取Cookie

HttpWebRequest的使用方法

例：

            Uri uri;
            uri = new Uri("www.baidu.com");

            HttpWebRequest webRqst = (HttpWebRequest)WebRequest.Create(url);

            webRqst.Method = "GET";
            webRqst.Accept = "*/*";
            webRqst.KeepAlive = false;
            webRqst.UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.141 Safari/537.36";
            webRqst.Headers.Add("Accept-Language", "zh-CN,zh;q=0.9,en-us;q=0.5");
			
			//1. 直接在Http头中添加Cookie
			//webRqst.Headers.Add("Cookie", cookieStr);

			2. 使用HttpWebRequest的CookieContainer属性进行设置
			CookieContainer ckCtnr = new CookieContainer();
            if (ckClctn != null)
            {
                ckCtnr.Add(ckClctn);
            }
			
			//获取应答网页
            webRqst.CookieContainer = ckCtnr;

            HttpWebResponse webRspn = (HttpWebResponse)webRqst.GetResponse();

（！）注意点

只有HttpWebRequest设置了CookieContainer变量后，使用HttpWebRequest的GetResponse()函数获取的HttpWebResponse对象才能获取Cookie，通过HttpWebResponse.Cookies属性获取应答网页得到的Cookie。

HttpWebResponse获取Cookie的方法

            CookieCollection cc;

            cc = webRspn.Cookies;
            
            string ckStr=string.Empty;

            IEnumerator emn;
            emn = cc.GetEnumerator();

            while (emn.MoveNext())
            {
                Cookie cookie;
                cookie = (Cookie)emn.Current;

                ckStr += cookie.Name + ":" + cookie.Value+";";
            }
            //MessageBox.Show(ckStr);

HttpWebResponse获取结果网页

            StreamReader sr = new StreamReader(webRspn.GetResponseStream(), Encoding.UTF8);

			string rslt;
            rslt = sr.ReadToEnd();

            sr.Close();

Cookie重用

与第一次使用Cookie通过CookieContainer的方法相同，将CookieCollection添加到CookieContainer中，并且将CookieContainer设置为HttpWebRequest的对应属性。

            HttpWebRequest webRqst = (HttpWebRequest)WebRequest.Create(url);

            webRqst.Method = "GET";
            webRqst.Accept = "*/*";
            webRqst.KeepAlive = false;
            webRqst.UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.141 Safari/537.36";
            webRqst.Headers.Add("Accept-Language", "zh-CN,zh;q=0.9,en-us;q=0.5");

			2. HttpWebRequest的CookieContainer属性进行设置
			CookieContainer ckCtnr = new CookieContainer();
            if (ckClctn != null)
            {
                ckCtnr.Add(ckClctn);  //此处的ckClctn是HttpWebResponse对象的Cookies属性
            }