C#post模拟登陆教务系统失败

问题描述

问 题

我在进行post登陆教务系统但是总是登陆不进去，返回给我的页面仍然是登陆页面，学校教务系统没有cookie返回只有url间的sessionid。麻烦各位大侠帮我看一下是什么地方的问题。

1、获取sessionid的代码

private string GetUrl()
        {
        string urlGetSession = "http://xk.zucc.edu.cn";
        HttpWebRequest reqGetSession =(HttpWebRequest)WebRequest.Create(urlGetSession);
        reqGetSession.Method = "GET";
        reqGetSession.KeepAlive = true;
            
            //禁止网页进行重定向
            reqGetSession.AllowAutoRedirect = false;
            reqGetSession.UserAgent = "Mozilla / 5.0(Windows NT 10.0; WOW64; rv: 51.0) Gecko / 20100101 Firefox / 51.0";
            //创建接受网页响应的对象
            HttpWebResponse resGetSession = (HttpWebResponse)reqGetSession.GetResponse();
            Stream streamGetSession = resGetSession.GetResponseStream();
            StreamReader srGetSession = new StreamReader(streamGetSession);
            string strGetSession = srGetSession.ReadToEnd();
            string[] strGetSessions = strGetSession.Split(new string[] { "/(",")/"},StringSplitOptions.None);
            return strGetSessions[1];

        }

2、获取验证码的代码

 private void GetValidateImage(string urlParma)
        {
            cookies = new CookieContainer();
            string url = "http://xk.zucc.edu.cn/(" + urlParma + ")/CheckCode.aspx";
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
            request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
            request.Method = "GET";
            request.UserAgent = "Mozilla / 5.0(Windows NT 10.0; WOW64; rv: 51.0) Gecko / 20100101 Firefox / 51.0";
            //request.CookieContainer = new CookieContainer(); //暂存到新的实例中
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();

            MemoryStream ms = null;
            using (var stream = response.GetResponseStream())
            {
                byte[] buffer = new byte[response.ContentLength];
                int offset = 0;
                int actuallyRead = 0;

                do
                {
                    actuallyRead = stream.Read(buffer, offset, buffer.Length - offset);
                    offset += actuallyRead;
                }
                while (actuallyRead > 0);
                ms = new MemoryStream(buffer);
            }
            response.Close();

            cookies = request.CookieContainer;//保存cookies
            //strCookies = request.CookieContainer.GetCookieHeader(request.RequestUri);//把cookies转换成字符串

            Bitmap bitmap = new Bitmap((Stream)ms);
            imgValidate.Image = bitmap;

        }

3、post登陆代码

private string Login2(string urlParma)
        {
            Encoding enc = Encoding.GetEncoding("gb2312");
            string postData = string.Format("__VIEWSTATE=dDwtNTE2MjI4MTQ7Oz7eLwpTkU0eZiReI563hfS1TF2rsQ%3D%3D&txtUserName={0}&Textbox1=&TextBox2={1}&txtSecretCode={2}&RadioButtonList1=% D1 % A7 % C9 % FA & Button1 = &lbLanguage = &hidPdrs = &hidsc = ", txtUserName.Text, txtPassword.Text, txtValidate.Text);
            //把要提交的数据转换成字节数组
            byte[] pb = enc.GetBytes(postData);

            string url = "http://xk.zucc.edu.cn/(" + urlParma + ")/default2.aspx";
            //新建一个请求
            HttpWebRequest myreq = (HttpWebRequest)WebRequest.Create(url);

            //指定请求的方法
            myreq.Method = "POST";
            myreq.ContentType = "application/x-www-form-urlencoded";
            myreq.UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36";
            
            //这里请求文本的长度就是我们字节数组的长度
            myreq.ContentLength = pb.Length;

            //获取提交流
            Stream str = myreq.GetRequestStream();
            str.Write(pb, 0, pb.Length);
            str.Close();
            WebResponse myresp = myreq.GetResponse();//获取返回的请求
            Stream revstr = myresp.GetResponseStream(); //获取流
            StreamReader readstr = new StreamReader(revstr,enc);//准备读取流     
            Char[] readc = new Char[256];
            //每次读256个「字符」
            int count = readstr.Read(readc, 0, 256);
            string restr = "";
            while (count > 0)
            {
                
                for(int i = 0;i < count;i++)
                {
                    restr += readc[i].ToString();                     
                }

                count = readstr.Read(readc,0,256);
            }
            readstr.Close();
            myresp.Close();
            restr = restr.Replace("\t","");
            return restr;
        }

winform的东西

解决方案

采用苏飞站长的HttpHelper类库重新分析了一遍，就可以顺利Post进去了

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