Question

我一直在使用HttpWebRequest来获取Cookie并抓取所需文档的网站。我一直在加载网站，然后在没有太多麻烦的情况下将它们分解为ViewState。然后我拍了一下。

Indiana WOTC website使用一个隐藏字段作为回邮的一部分。该字段名为“ lt”，并随页面随机生成。我无法加载页面并获取代码，因为当我访问页面以输入帖子数据时，代码会更改。

这是我的cookie获取代码；

private CookieContainer GetCookies(string Login_URL, List<Post_Parameters> parameters) 
{
    HttpWebRequest webRequest = WebRequest.Create(Login_URL) as HttpWebRequest;
    string responseData = "";
    using (StreamReader responseReader = new StreamReader(webRequest.GetResponse().GetResponseStream())) 
    {
        responseData = responseReader.ReadToEnd();
    }
    List<string> ParameterSet = new List<string>();
    foreach (Post_Parameters item in parameters) 
    {
        if (item.Value == "???") 
        {
            ParameterSet.Add(item.Attribute.Trim('"') + "=" + Extract(responseData, item.Attribute));
        } 
        else 
        {
            ParameterSet.Add(item.Attribute.Trim('"') + "=" + item.Value);
        }
    }
    string postData = string.Join("&", ParameterSet);
    CookieContainer cookies = new CookieContainer();
    webRequest = WebRequest.Create(Login_URL) as HttpWebRequest;
    webRequest.Method = "POST";
    webRequest.ContentType = "application/x-www-form-urlencoded";
    webRequest.CookieContainer = cookies;


    using (StreamWriter requestWriter = new StreamWriter(webRequest.GetRequestStream())) 
    {
        requestWriter.Write(postData);
    }

    //Debug Logins
    using (StreamReader responseReader = new StreamReader(webRequest.GetResponse().GetResponseStream())) 
    {
        //    Console.Write(responseReader.ReadToEnd());
    }
    return cookies;
}

private string Extract(string s, string d)
{
    string viewStateNameDelimiter = d;
    string valueDelimiter = "value=\"";
    int viewStateNamePosition = s.IndexOf(viewStateNameDelimiter);
    int viewStateValuePosition = s.IndexOf(valueDelimiter, viewStateNamePosition);
    int viewStateStartPosition = viewStateValuePosition + valueDelimiter.Length;
    int viewStateEndPosition = s.IndexOf("\"", viewStateStartPosition);
    string x = "";
    x = WebUtility.UrlEncode(s.Substring(viewStateStartPosition, viewStateEndPosition - viewStateStartPosition));
    return x;
}

private struct Post_Parameters 
{
    public string Attribute { get; set; }
    public string Value { get; set; }
}

这是我通常使用的方式；

string LOGIN_URL = "https://wotc.jfs.ohio.gov/UserLogin.aspx?ReturnUrl=%2f";
List<Post_Parameters> x = new List<Post_Parameters>();
x.Add(new Post_Parameters { Attribute = "__VIEWSTATEGENERATOR", Value = "???" });
x.Add(new Post_Parameters { Attribute = "__EVENTVALIDATION", Value = "???" });
x.Add(new Post_Parameters { Attribute = "__VIEWSTATE", Value = "???" });
x.Add(new Post_Parameters { Attribute = "ctl00%24ContentPlaceHolder1%24Login1%24Fein", Value = "*****" });
x.Add(new Post_Parameters { Attribute = "ctl00%24ContentPlaceHolder1%24Login1%24UserId", Value = "*****" });
x.Add(new Post_Parameters { Attribute = "ctl00%24ContentPlaceHolder1%24Login1%24Password", Value = "*****" });
x.Add(new Post_Parameters { Attribute = "ctl00%24ContentPlaceHolder1%24Login1%24LoginButton", Value = "Log+In" });
x.Add(new Post_Parameters { Attribute = "ctl00_ContentPlaceHolder1_rlvBreakingNews_ClientState", Value = "" });
var i = GetCookies(LOGIN_URL, x);

这是我在印第安纳州网站上使用它的方式；

string LOGIN_URL = "https://webapps.dwd.in.gov/DWDAuthentication/login?service=https%3A%2F%2Fwebapps.dwd.in.gov%2FeWotc%2Fdefault-flow.htm";
List<Post_Parameters> x = new List<Post_Parameters>();
x.Add(new Post_Parameters { Attribute = "username", Value = "*****" });
x.Add(new Post_Parameters { Attribute = "password", Value = "*****" });
x.Add(new Post_Parameters { Attribute = "_eventId_signIn", Value = "Sign+In" });
x.Add(new Post_Parameters { Attribute = "\"lt", Value = "Some How Post the Hidden Field from the Page" });
x.Add(new Post_Parameters { Attribute = "execution", Value = "???" });
var i = TestGetCookies(LOGIN_URL, x);

基本上，我需要以某种方式将页面的隐藏字段发送到POST。我认为这是不可能的，因为我正在用POST数据加载页面。

在不使用WebBrowser控件的情况下是否有可能？如果是这样，我将如何开始工作？

通过HttpWebRequest从页面转发隐藏字段

0 个答案: