解决了!!!首先添加这个 cookie 容器:
using System;
using System.Net;
namespace ConsultaCNPJ
{
public class CookieAwareWebClient : WebClient
{
private CookieContainer _mContainer;
public void SetCookieContainer(CookieContainer container)
{
_mContainer = container;
}
protected override WebRequest GetWebRequest(Uri address)
{
WebRequest request = base.GetWebRequest(address);
var webRequest = request as HttpWebRequest;
if (webRequest != null)
{
webRequest.CookieContainer = _mContainer;
webRequest.KeepAlive = true;
webRequest.ProtocolVersion = HttpVersion.Version10;
}
return request;
}
}
}
然后将您的代码编辑为:
using System;
using System.Drawing;
using System.IO;
using System.Net;
using System.Text;
using System.Text.RegularExpressions;
namespace ConsultaCNPJ
{
public class ConsultaCNPJBroker
{
private readonly CookieContainer _cookies = new CookieContainer();
public String DominioReceitaFederal = "http://www.receita.fazenda.gov.br";
public String GetDataReceitaFederal = "/pessoajuridica/cnpj/cnpjreva/cnpjreva_solicitacao2.asp";
public String PostDataReceitaFederal = "/pessoajuridica/cnpj/cnpjreva/valida.asp";
private String _viewState;
public Bitmap GetCaptcha()
{
const string strViewState = "<input type=hidden id=viewstate name=viewstate value='";
const string strImagemCaptcha = "<img border='0' id='imgcaptcha' alt='Imagem com os caracteres anti robô' src='";
String htmlResult;
using (var wc = new CookieAwareWebClient())
{
wc.SetCookieContainer(_cookies);
wc.Headers[HttpRequestHeader.UserAgent] = "Mozilla/4.0 (compatible; Synapse)";
wc.Headers[HttpRequestHeader.KeepAlive] = "300";
htmlResult = wc.DownloadString(DominioReceitaFederal + GetDataReceitaFederal);
}
if (htmlResult.Length > 0)
{
_viewState = htmlResult;
int posString = _viewState.IndexOf(strViewState, StringComparison.Ordinal);
_viewState = _viewState.Substring(posString + strViewState.Length);
posString = _viewState.IndexOf("'>", StringComparison.Ordinal);
_viewState = _viewState.Substring(0, posString);
String urlImagemCaptcha = htmlResult;
posString = urlImagemCaptcha.IndexOf(strImagemCaptcha, StringComparison.Ordinal);
urlImagemCaptcha = urlImagemCaptcha.Substring(posString + strImagemCaptcha.Length);
posString = urlImagemCaptcha.IndexOf("'>", StringComparison.Ordinal);
urlImagemCaptcha = urlImagemCaptcha.Substring(0, posString);
urlImagemCaptcha = urlImagemCaptcha.Replace("amp;", "");
if (urlImagemCaptcha.Length > 0)
{
var wc2 = new CookieAwareWebClient();
wc2.SetCookieContainer(_cookies);
wc2.Headers[HttpRequestHeader.UserAgent] = "Mozilla/4.0 (compatible; Synapse)";
wc2.Headers[HttpRequestHeader.KeepAlive] = "300";
byte[] data = wc2.DownloadData(DominioReceitaFederal + urlImagemCaptcha);
return new Bitmap(
new MemoryStream(data));
}
return null;
}
_viewState = "";
return null;
}
public Stream Consulta(string aCNPJ, string aCaptcha, bool removerEspacosDuplos)
{
var request = (HttpWebRequest) WebRequest.Create(DominioReceitaFederal + PostDataReceitaFederal);
request.ProtocolVersion = HttpVersion.Version10;
request.CookieContainer = _cookies;
request.Method = "POST";
string fviewstate = _viewState;
fviewstate = Uri.EscapeDataString((fviewstate));
string postData = "";
postData = postData + "origem=comprovante&";
postData = postData + "viewstate=" + fviewstate + "&";
postData = postData + "cnpj=" + new Regex(@"[^\d]").Replace(aCNPJ, string.Empty) + "&";
postData = postData + "captcha=" + aCaptcha + "&";
postData = postData + "captchaAudio=&";
postData = postData + "submit1=Consultar&";
postData = postData + "search_type=cnpj";
byte[] byteArray = Encoding.UTF8.GetBytes(postData);
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = byteArray.Length;
Stream dataStream = request.GetRequestStream();
dataStream.Write(byteArray, 0, byteArray.Length);
dataStream.Close();
WebResponse response = request.GetResponse();
return response.GetResponseStream();
}
}
}
就是这样!
特别感谢我的好朋友 CunhaW!
用法:
首先创建一个带有 PictureBox 和一个 TextBox 的表单以及这样的验证码代理
private readonly ConsultaCNPJBroker _broker = new ConsultaCNPJBroker();
this.ImgCaptcha = new System.Windows.Forms.PictureBox();
this.TbxCaptcha = new System.Windows.Forms.TextBox();
然后使用类似 2-Steps 查询,首先获取验证码,然后使用验证码进行查询
private void UpdateCaptcha()
{
ImgCaptcha.Image = _broker.GetCaptcha();
TbxCaptcha.Text = string.Empty;
}
这里需要用户交互来解决验证码并填充文本框,最后
private void BtnExecute_OnClick(object sender, EventArgs e)
{
var pessoaJuridica = _broker.Consulta(TbxCNPJ.Text, TbxCaptcha.Text, true);
// here you can see props like pessoaJuridica.CNPJ
}