C#带cookie Post和Get方式发送数据，保持cookie

在实际编程中，可能需要读取特定网页的信息，但很多网站需要用户登录后，才能够获取相关的页面内容，这就需要编程者先临时存储当前的cookie，
在C#中可以使用CookieContainer 对象来保存登录后的Cookie信息，这样，在每次发送数据的时候，附加上Cookie信息，就可以了。

#region 同步通过POST方式发送数据
       /// <summary>
       /// 通过POST方式发送数据
       /// </summary>
       /// <param name="Url">url</param>
       /// <param name="postDataStr">Post数据</param>
       /// <param name="cookie">Cookie容器</param>
       /// <returns></returns>
       public string SendDataByPost(string Url,string postDataStr,ref CookieContainer cookie)
       {
         HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
         if (cookie.Count == )
         {
            request.CookieContainer = new CookieContainer();
            cookie = request.CookieContainer;
         }
         else
         {
            request.CookieContainer = cookie;
         }
 
         request.Method = "POST";
         request.ContentType = "application/x-www-form-urlencoded";
         request.ContentLength = postDataStr.Length;
         Stream myRequestStream = request.GetRequestStream();
         StreamWriter myStreamWriter = new StreamWriter(myRequestStream, Encoding.GetEncoding("gb2312"));
         myStreamWriter.Write(postDataStr);
         myStreamWriter.Close();
 
         HttpWebResponse response = (HttpWebResponse)request.GetResponse();
         Stream myResponseStream = response.GetResponseStream();
         StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));
         string retString= myStreamReader.ReadToEnd();
         myStreamReader.Close();
         myResponseStream.Close();
 
         return retString;
       }
       #endregion
 
       #region 同步通过GET方式发送数据
       /// <summary>
       /// 通过GET方式发送数据
       /// </summary>
       /// <param name="Url">url</param>
       /// <param name="postDataStr">GET数据</param>
       /// <param name="cookie">GET容器</param>
       /// <returns></returns>
       public string SendDataByGET(string Url, string postDataStr, ref CookieContainer cookie)
       {
         HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url +( postDataStr == "" ? "" : "?") + postDataStr);
         if (cookie.Count == )
         {
            request.CookieContainer = new CookieContainer();
            cookie = request.CookieContainer;
         }
         else
         {
            request.CookieContainer = cookie;
         }
 
         request.Method = "GET";
         request.ContentType = "text/html;charset=UTF-8";
 
         HttpWebResponse response = (HttpWebResponse)request.GetResponse();
         Stream myResponseStream = response.GetResponseStream();
         StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));
         string retString = myStreamReader.ReadToEnd();
         myStreamReader.Close();
         myResponseStream.Close();
 
         return retString;
       }
       #endregion
 
操作代码
 
CookieContainer cc=new CookieContainer();
cc.Add(new System.Uri("http://www.baidu.com "), new Cookie("PHPSESSID", "xx"));
string content =  web.SendDataByGET("http://www.baidu.com/xx/yy.php","","gbk",ref cc);
MessageBox.Show(content);