Implementing reCaptcha in ASP.NET

Question

I am trying to insert a captcha in my ASP.NET code. Basically, in the lbt_proceed_click() method, I want the browser to proceed to the next page using Response.Redirect("foo") only if the captcha entered is correct.

I searched, but could not find a solution, especially since I am not using a form to send data, but writing to a database directly, and then moving to the next page using Response.Redirect().

Answer 1

1. go to the reCAPTCHA site and register for a unique key
2. Download reCAPTCHA .NET Library
3. Create and Save your Public and Private keys safely
4. In the website we add a reference to library/bin/Release/Recaptcha.dll

5. after the @Page directive, insert the following code:

   <%@ Register TagPrefix="recaptcha" Namespace="Recaptcha" Assembly="Recaptcha"%>
   

6. add control in asp.net tag:

           <recaptcha:RecaptchaControl
   
           ID="recaptcha"
   
           runat="server"
   
           PublicKey="Your very own public key here"
   
           PrivateKey="Your very own privat key here"
   
      />
   

7. add button and label to your form

8. add the following button click method(btnSubmit_Click) in code behind file :

   if (Page.IsValid)
   {   
       lblResult.Text = "You Got It!"; // Or Use Response.redirect("foo");
   }
        else
   {
       lblResult.Text = "Incorrect";
   }
   

9. Test your Page!