Question

I need to be able to place the captcha image into a picturebox on my form, the reason being that I need to zoom the captcha image for the visualy impaired users.

It appears to be such a simple task, just take the image from the web page and put it into a picturebox but it is turning out to be not so simple.
i have WebBrowser control in form and for registration in one of site, i need captcha image in picture box. problem is that captcha image is generated by JavaScript, when java script runs then it gives url of captcha image. but every time when java script runs, captcha image goes change. i just want that captcha image which is on WebBrowser control current page.

Any help would be greatly appreciated.

---

here is my code.

public void FacebookRegistration()
{
  HTMLDoc = (mshtml.HTMLDocument)WBrowser.Document.DomDocument;
  iHTMLCol = HTMLDoc.getElementsByTagName("input");
  foreach (IHTMLElement iHTMLEle in iHTMLCol)
  {
    if (iHTMLEle.getAttribute("name", 0) != null)
    {
      strAttriName = iHTMLEle.getAttribute("name", 0).ToString();
      if (strAttriName == "firstname")
      {
        iHTMLEle.setAttribute("value", FirstName, 0);
        continue;
      }
      if (strAttriName == "lastname")
      {
        iHTMLEle.setAttribute("value", LastName, 0);
        continue;
      }
      if (strAttriName == "reg_email__")
      {
        iHTMLEle.setAttribute("value", EmailID, 0);
        continue;
      }
      if (strAttriName == "reg_passwd__")
      {
        string s = GetRandomString();
        Random ran = new Random();
        iHTMLEle.setAttribute("value", s+ran.Next(1111,9999), 0);
        break;
      }
    }
  }
  iHTMLCol = HTMLDoc.getElementsByTagName("option");
  foreach (IHTMLElement iHTMLEle in iHTMLCol)
  {
    try
    {
      if (iHTMLEle.innerText.Contains("Male"))
      {
        iHTMLEle.setAttribute("selected", "selected",0);
      } 
      if (iHTMLEle.innerText.Contains("Jun"))
      {
        iHTMLEle.setAttribute("selected", "selected", 0);
      }
      Random ran = new Random();
      if (iHTMLEle.innerText.Contains("4"))
      {
        iHTMLEle.setAttribute("selected", "selected", 0);
      }
      Random ran1 = new Random();
      if (iHTMLEle.innerText.Contains(ran1.Next(1920,1985).ToString()))
      {
        iHTMLEle.setAttribute("selected", "selected", 0);
      }
    }
    catch { }
  }

  iHTMLCol = HTMLDoc.getElementsByTagName("input");
  int i = 0;
  foreach (IHTMLElement iHTMLEle in iHTMLCol)
  {
    string s = iHTMLEle.className;
    if (iHTMLEle.className == "UIButton_Text" && iHTMLEle.getAttribute("value", 0).ToString() == "Sign Up")
    {
      if (i != 0)
      {
        iHTMLEle.click();
        break;
      }
      i++;
    }
  }

  private void WBrowser_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
  {
    if (CurrentSocial == "facebook")
    {
      FacebookRegistration();
    }
  }
}

in the registration page of facebook.com, there is captcha and if you go to page source then you will see only this:

<input type="hidden" id="captcha_persist_data" name="captcha_persist_data" value="AAAAAQAQiCw5zhFGOsVF6TbDBX8d_wAAAGvqENqFy5KkvMip5AIv3QSF7BS7goiHfAC7fTkzr8hW61cq3s1d23Tw7m-WAi-21Uzt1l3frkLf4obBEuZZMwga_hbcUhnWXu4P382QsJ7J0WtAbo5USXWuVjzv_KD1SMyTWhf34AGorQd27dFqZc0a" /?;

and in this input tag, i found url of that javascript which gives captcha url

javascript url: http://api.recaptcha.net/challenge?k=6LezHAAAAAAAADqVjseQ3ctG3ocfQs2Elo1FTa_a&ajax=1&xcachestop=0.31520985781374&authp=nonce.tt.time.new_audio_default&psig=H48rD9d3_QogBfxxKAmzFZ7CG10&nonce=hl77BQn58EsYsPpPwQ2TIA&tt=r3zaWETv27-0igoIw5ndwnHt_W4&time=1256413208&new_audio_default=1

if you browse this url you will get captcha url like this:

var RecaptchaState = {
challenge : '02UflxsCli4nYg-oG48n5bNDm6ywMlvE62UwXQssF__eJAfSiv2TXuac-1tbu2FThwakgH65IdExWDy9qyr1sYbRuwyQFZD7Dk1eE_fXuoSn9tliqnYeMq__LEF6-GTEm0H6TChOtvpwL2G3C1BsBriw8FFaKqkaTwbNoJeAfzI_j9qYnPaqtHJYillevhRsxyaQVYfLvqai7p0Sfu3849BFpamlbfE3to3KTXi5cZ0xlmuGkMkuZhvq_GyK_z-ZXq9z_Ls8xZlywN0jlIOsSEvI9QJq_69X-X3Moq9lFBcmqWYaKbf7faRQt19aJGB4DdBC1PqQIC',
timeout : 25000,
server : 'http://api.recaptcha.net/',
site : '6LezHAAAAAAAADqVjseQ3ctG3ocfQs2Elo1FTa_a',
error_message : '',
programming_error : '',
is_incorrect : false
};

Recaptcha.challenge_callback();

and original captcha url look like this:

http://api.recaptcha.net/image?c=027CxC4LbBbzVJKy-1xX_wRBf7Gmi4AvgikDVaKeYjBCmiX4XBzGymWC7XRfWx4LLQgfscKnfeB7U305MhlVN0X4vAkrK84ac3jybRJ3UJPUQ8rnlJOS7lqNqpRpolYSd6WBxMShhrzqbx-5ScL0JAsN7cJRMLMqeQsPHg1QB7g4kp4KxKO1aEONsUibahnCC8baLHGSIYJ5Q1Gcr1MPvJ9i_a5qQCilT1tWXwAKE_fkVGi31_un3OxHbNm9UmMemRp7IZ9C9ZLU4IjMApxVJOWXMYqjt588z_ZVcYG2dtY6Dh0b4R1aAQcp0UXFTggdWtsjPw7wIC

then you will get captcha, but is is not what i want , because javascript everytime changes the capthca image. so i dont get captcha which is currently being shown in webbrowser

Answer 1

You can copy the image to the clipboard and read from there. Alternatively you can parse the page to get the image’s URL and see if you can dig the image file out of the cache

How To Programmatically Copy an IMG Element to the Clipboard