HttpWebRequest模拟登陆，存储Cookie以便登录请求后使用

[一篮饭特稀原创，转载请注明出自http://www.cnblogs.com/wanghafan/p/3284481.html]

PostLogin ：登录，并保存Cookie

 1  public static string PostLogin(string postData, string requestUrlString, ref CookieContainer cookie)
 2     {
 3         ASCIIEncoding encoding = new ASCIIEncoding();
 4         byte[] data = encoding.GetBytes(postData);
 5         //向服务端请求
 6         HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create(requestUrlString);
 7         myRequest.Method = "POST";
 8         myRequest.ContentType = "application/x-www-form-urlencoded";
 9         myRequest.ContentLength = data.Length;
10         myRequest.CookieContainer = new CookieContainer();
11         Stream newStream = myRequest.GetRequestStream();
12         newStream.Write(data, 0, data.Length);
13         newStream.Close();
14         //将请求的结果发送给客户端(界面、应用)
15         HttpWebResponse myResponse = (HttpWebResponse)myRequest.GetResponse();
16         cookie.Add(myResponse.Cookies);
17         StreamReader reader = new StreamReader(myResponse.GetResponseStream(), Encoding.UTF8);
18         return reader.ReadToEnd();
19     }

PostRequest ：登录后使用Cookie进行其他操作

 1  public static string PostRequest(string postData, string requestUrlString, CookieContainer cookie)
 2     {
 3         ASCIIEncoding encoding = new ASCIIEncoding();
 4         byte[] data = encoding.GetBytes(postData);
 5         HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create(requestUrlString);
 6         myRequest.Method = "POST";
 7         myRequest.ContentType = "application/x-www-form-urlencoded";        
 8         myRequest.ContentLength = data.Length;
 9         myRequest.CookieContainer = cookie;
10         Stream newStream = myRequest.GetRequestStream();
11         newStream.Write(data, 0, data.Length);
12         newStream.Close();
13         HttpWebResponse myResponse = (HttpWebResponse)myRequest.GetResponse();
14         StreamReader reader = new StreamReader(myResponse.GetResponseStream(), Encoding.UTF8);
15         return reader.ReadToEnd();
16     }

e.g.

1             string strIMSPhone = tb_IMSPhone.Text.Trim();
2             string strIMSPwd = tb_IMSPwd.Text.Trim();
3             string postData = "username=" + strIMSPhone + "&password=" + strIMSPwd + "&type=2";
4             CookieContainer cookie=new CookieContainer();
5             if (IMSHelper.PostLogin(postData, post_signIn, ref cookie).Equals("ok"))
6             {
7                 string strCont = PostRequest("", post_getContJsonData, cookie);    
8             }