This post originated from an RSS feed registered with .NET Buzz by Scott Hanselman. Original Post: A potential CAPTCHA Comment Spam Solution for dasBlog (and others) with no recompile or code changes Feed Title: Scott Hanselman's ComputerZen.com Feed URL: http://radio-weblogs.com/0106747/rss.xml Feed Description: Scott Hanselman's ComputerZen.com is a .NET/WebServices/XML Weblog. I offer details of obscurities (internals of ASP.NET, WebServices, XML, etc) and best practices from real world scenarios. Latest .NET Buzz Posts Latest .NET Buzz Posts by Scott Hanselman Latest Posts From Scott Hanselman's ComputerZen.com

I took Jeff Atwood's CAPTCHA example and added a new event called "UserValidationEvent"

Public Event UserValidationEvent As EventHandler

Then I raise the event at the VERY end of ValidateCaptcha I raise it:

RaiseEvent UserValidationEvent(Me, New EventArgs)

I made it a separate event because I want the CaptchaControl to integrate with my blogging software WITHOUT any code on the server side.  I didn't want to have to recompile dasBlog or check anything in the Page_Load.

I made the appropriate web.config changes as per Jeff's instructions, and I added the control to the CommentViewBox.ascx and put this code at the top:

<%@ Register TagPrefix="cc1" Namespace="WebControlCaptcha" Assembly="WebControlCaptcha" %>
<script Language="C#" Runat="Server">
  protected void Foo(object sender, System.EventArgs e)
  {
  if (Page.IsPostBack == true && CaptchaControl1.UserValidated == false)
   {
    Response.Redirect(Request.RawUrl);
   }
  }

  protected void Page_Load(object sender, System.EventArgs e)
  {
   //Ya, ya, I know I could have hooked this event up a number of ways
   // including AutoEventWireUp but I like this fine, and it feels
   // more explicit to moi.
   CaptchaControl1.UserValidationEvent += new EventHandler(Foo);
  }  
</script>

There are a few Font issues to work out...he has it setup with a number of "no-no" fonts, while I'd prefer a list of "allowed" fonts.