无法使用WebClient登录到asp.net网站

Question

我试图在此网站上提交表单： freeclassifieds，使用支持Cookie的WebClient。 我升级Web客户端：

public class CookieWebClient : WebClient 
{ 
    private readonly CookieContainer container = new CookieContainer(); 

    public CookieWebClient(CookieContainer container) 
    { 
     this.container = container; 
    } 

    protected override WebRequest GetWebRequest(Uri address) 
    { 
     WebRequest res = base.GetWebRequest(address); 
     var request = res as HttpWebRequest; 
     if (request != null) 
     { 
      request.CookieContainer = container; 
     } 
     return res; 
    } 

    protected override WebResponse GetWebResponse(WebRequest request, IAsyncResult result) 
    { 
     WebResponse response = base.GetWebResponse(request, result); 
     ReadCookies(response); 
     return response; 
    } 

    protected override WebResponse GetWebResponse(WebRequest request) 
    { 
     WebResponse response = base.GetWebResponse(request); 
     ReadCookies(response); 
     return response; 
    } 

    private void ReadCookies(WebResponse r) 
    { 
     var response = r as HttpWebResponse; 
     if (response != null) 
     { 
      CookieCollection cookies = response.Cookies; 
      container.Add(cookies); 
     } 
    } 
} 

但是，当我试图提交表单，我只是得到阻止，接收到登录页面作为响应。 我检查了登录页面中的cookie和字段，似乎一切都被调整了。 成功登录后，为什么我无法收到正确的页面？

static void Main(string[] args) 
    { 
     string link1 = "http://www.freeclassifieds.com/logon.aspx"; 

     string fileName= @"D:\Dropbox\myProjects\AutoPostMachine\myHtml.html"; 

     CookieWebClient wc = new CookieWebClient(new CookieContainer()); 

     NameValueCollection postDataCollection= new NameValueCollection(); 
     postDataCollection.Add("ctl00$phMain$txtEmail", "myEmail"); 
     postDataCollection.Add("ctl00$phMain$txtPassword","myPassword"); 
     postDataCollection.Add("ctl00$phMain$btnLogin","Login"); 

     wc.Encoding = Encoding.UTF8; 
     wc.Credentials = CredentialCache.DefaultCredentials; 
     wc.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded"; 
     wc.Headers[HttpRequestHeader.Cookie] = "ASP.NET_SessionId=mfqdx1505nnbw3bxws01so12; __utma=19755559.732186057.1355692154.1355692154.1355695835.2; __utmb=19755559.3.10.1355695835; __utmc=19755559; __utmz=19755559.1355692154.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none)"; 

     byte[] byteArr= wc.UploadValues(link1, postDataCollection); 
     FileStream fs = new FileStream(fileName, FileMode.Create); 
     fs.Write(byteArr, 0, byteArr.Length); 

     Process.Start(fileName); 
    } 

Answer 1

如果/当正确配置，你不能 “欺骗” 一个ASP.Net Web窗体Postback - MSDN参考：VIEWSTATE and EVENTVALIDATION