C# 通过post发布dede(织梦)登录并发布文章

求助，就结了我好久的问题 好久好久。现在登录能成功 至于有没有取回有效的cookie那就不知道了  发布文章的时候总是返回失败  并返回了登录界面的信息。  怎么改？
Encoding enc = Encoding.GetEncoding("gb2312");
        CookieContainer cc = new CookieContainer();
        Thread t;
        public void dedelogin()//登录
        {
            HttpWebRequest myReq = (HttpWebRequest)WebRequest.Create("http://127.0.0.1/dede/login.php");
            myReq.Accept = "image/jpeg, application/x-ms-application, image/gif, application/xaml+xml, image/pjpeg, application/x-ms-xbap, */*";
            myReq.Method = "post";
            myReq.UserAgent = "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET4.0C; .NET4.0E; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)";
            myReq.ContentType = "application/x-www-form-urlencoded";
            myReq.Referer = "http://www.jobqn.com";
            string s = "gotopage=%2Fdedexiake%2F&dopost=login&adminstyle=newdedecms&userid=admin&pwd=admin&sm1=%B5%C7%C2%BC";
            byte[] arrB = enc.GetBytes(s);            if (cc.Count == 0)
            {
                myReq.CookieContainer = new CookieContainer();
                cc = myReq.CookieContainer;
            }
            else
            {
                myReq.CookieContainer = cc;
            }
            Stream outStream = myReq.GetRequestStream();
            outStream.Write(arrB, 0, arrB.Length);
            outStream.Close();
            HttpWebResponse myResp = null;
            try
            {
                //接收HTTP做出的响应  
                myResp = (HttpWebResponse)myReq.GetResponse();
            }
            catch {richTextBox1.Text += "响应失败\r\n";}
            Stream ReceiveStream = myResp.GetResponseStream();
            StreamReader readStream = new StreamReader(ReceiveStream, enc);
            Char[] read = new Char[256];
            int count = readStream.Read(read, 0, 256);
            string str = null;
            while (count > 0)
            {
                str += new String(read, 0, count);
                count = readStream.Read(read, 0, 256);
            }            myReq.CookieContainer = cc;
            foreach (Cookie cookie in myResp.Cookies)
            {
                cc.Add(cookie);
            }            readStream.Close();
            myResp.Close();
            if (str.Contains("转向"))
            {
                richTextBox1.Text += "登录成功\r\n";
                Thread.Sleep(1000);
                dedefatie();
            }
            else { richTextBox1.Text += "登录失败\r\n"; }        }
        public void dedefatie()
        {
            string content = "";
            string con = File.ReadAllText(@"data/dede.txt", Encoding.Default);
            content = con.Replace("[标题]", tb_title.Text);
            content = content.Replace("[内容]",tb_nr.Text);            byte[] arrB = enc.GetBytes(content);            HttpWebRequest myReq = (HttpWebRequest)WebRequest.Create("http://127.0.0.1/dede/article_add.php");
            myReq.UserAgent = "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E)";
            myReq.CookieContainer = cc;//用证书
            myReq.Method = "post";
            myReq.ContentType = "multipart/form-data; boundary=-----------------------------7dbff3980c74";
            myReq.Referer = " http://127.0.0.1";
            myReq.ContentLength = arrB.Length;            Stream outStream = myReq.GetRequestStream();
            outStream.Write(arrB, 0, arrB.Length);
            outStream.Close();
            WebResponse myResp = null;            //接收HTTP做出的响应  
            myResp = myReq.GetResponse();
            Stream ReceiveStream = myResp.GetResponseStream();
            StreamReader readStream = new StreamReader(ReceiveStream, enc);
            Char[] read = new Char[256];
            int count = readStream.Read(read, 0, 256);
            string str = null;
            while (count > 0)
            {
                str += new String(read, 0, count);
                count = readStream.Read(read, 0, 256);
            }            if (str != "")
            {
                readStream.Close();
                myResp.Close();
                textBox2.Text = str;
                if (str.Contains("成功"))
                {
                    richTextBox1.Text += "发布成功\r\n";                }
                else
                {
                    richTextBox1.Text += "发布失败了\r\n";
                }            }
            else
            { 
                richTextBox1.Text += "发布失败咯\r\n"; 
            }            t.Abort();        }
        private void button1_Click(object sender, EventArgs e)
        {
            CheckForIllegalCrossThreadCalls = false;
            t = new Thread(dedelogin);
            t.Start();
        }