如何使用c#以编程方式登录到不返回html响应的网站？它在调用GetResponse（）时挂起

我试图使用C#以编程方式登录到一个网站（“”），但程序在第二个GetResponse（）请求时挂起，我尝试通过POST方法登录并填充表单字段

        public String GetWebContent(String username, String password)
        {

        //The URL of the Login Form of the website
        String urlSignin = "http://www.smscountry.com/";

        //The action URL of the Login Form of the website on Submit
        String urlLogin = "http://www.smscountry.com/LoginCheck.asp?msg=";

        //Initializes the Uri object of the URLs
        Uri uriSignin = new Uri(urlSignin);
        Uri uriLogin = new Uri(urlLogin);

        //Hashtable to store the form details
        Hashtable formData = new Hashtable();
        formData.Add("UTC", new Hashtable());
        formData.Add("txt_Username", new Hashtable());
        formData.Add("txt_Password", new Hashtable());

        ((Hashtable)formData["UTC"])["value"] = -330;
        ((Hashtable)formData["txt_Username"])["value"] = username;
        ((Hashtable)formData["txt_Password"])["value"] = password;

        //Initializing the data for the post action
        String postData = "";

        foreach (string name in formData.Keys)
        {
              postData += "&" + name + "=" + ((Hashtable)formData[name])["value"];
        }
        postData = postData.Substring(1);

        System.Text.ASCIIEncoding encoding = new System.Text.ASCIIEncoding();
        byte[] data = encoding.GetBytes(postData);

        HttpWebRequest webReq;
        HttpWebResponse webResp;

        //To store the cookies of the response objects to be used for the next request
        CookieContainer cookies = new CookieContainer();

        String responseString = "";

        try
        {
            //Getting response for the Signin page  
            webReq = (HttpWebRequest)WebRequest.Create(urlSignin);
            webResp = (HttpWebResponse)webReq.GetResponse();

            //Storing response cookies to be used in the next request
            cookies.Add(webResp.Cookies);

            //Storing ASPSESSION cookie that appears in the Response header Set-Cookie to be used in the next request
            string sessionCookie = webResp.Headers["Set-Cookie"];
            responseString = new StreamReader(webResp.GetResponseStream()).ReadToEnd();

            string respCookie = sessionCookie.Substring(0, sessionCookie.IndexOf(';'));
            char[] separator  = {'='};
            string[] cookieValues = respCookie.Split(separator);
            cookies.Add(new Cookie(cookieValues[0], cookieValues[1], "/", "www.smscountry.com"));

            //Initializing the request object for log in
            webReq = (HttpWebRequest)WebRequest.Create(urlLogin);
            webReq.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
            webReq.Referer = urlSignin;
            webReq.KeepAlive = true;
            webReq.Method = "POST";
            webReq.ContentType = "application/x-www-form-urlencoded";
            webReq.ContentLength = data.Length;
            webReq.AllowAutoRedirect = false;
            webReq.CookieContainer = cookies;
            webReq.Timeout = 30000;
            webReq.ReadWriteTimeout = 60000;


            //Get the response for the request to log in
            //PROBLEM OCCURS HERE - THE CODE DOES NOT EXECUTE FURTHER
            webResp = (HttpWebResponse)webReq.GetResponse();
            responseString = new StreamReader(webResp.GetResponseStream()).ReadToEnd();

            webResp.Close();
            return responseString;
        }
        catch (Exception ex)
        {
            throw ex;

        }

    }

---

我不明白问题出在哪里。我认为这可能与页面被重定向以及没有返回html响应有关，但我不能完全确定。这个问题有解决办法吗？或者是否有其他方法可以登录此特定网站？

问题出现在以下行：

webReq.ContentLength=data.Length

在这里，您将POST请求正文的长度设置为大于零，而实际正文为空；您要发送的只是标题。将该行替换为

webReq.ContentLength=0完成了。
问题在下面一行：
webReq.ContentLength=data.Length
在这里，您将POST请求正文的长度设置为大于零，而实际正文为空；您要发送的只是标题。将该行替换为
webReq.ContentLength=0完成。在收到回复之前，您需要发送数据。Igor看到您正在设置请求的内容长度，但您需要将内容发送到服务器，而不是将内容长度设置为0：

...
webReq.GetRequestStream().write( data, 0, data.Length );
webReq.GetRequestStream().close();
webResp = (HttpWebResponse)webReq.GetResponse();
responseString = new StreamReader(webResp.GetResponseStream()).ReadToEnd();
...

您没有收到响应的原因是服务器正在等待您发送数据。长度字节数。
您需要先发送数据，然后才能收到响应。Igor看到您正在设置请求的内容长度，但您需要将内容发送到服务器，而不是将内容长度设置为0：

...
webReq.GetRequestStream().write( data, 0, data.Length );
webReq.GetRequestStream().close();
webResp = (HttpWebResponse)webReq.GetResponse();
responseString = new StreamReader(webResp.GetResponseStream()).ReadToEnd();
...

您没有收到响应的原因是服务器正在等待您发送数据。长度字节数。
是的，这就是问题所在。谢谢是的，这就是问题所在。谢谢