ASP.NET Hosting Tips :: How to Add reCAPTCHA to ASP.NET Site

I recently implemented a reCAPTCHA control into an ASP.NET website and it was so incredibly easy I thought I’d write a post about it.

Implementation Steps

The steps to implement the control are as follows:

1. Setup a Google account, if you don’t already have one
2. Sign into your Google account and create a new reCAPTCHA key by entering in your website’s URL
3. Make a note of the public and private keys provided on the following page
4. Download the most recent reCAPTCHA assembly for the .NET framework
5. Open the ASP.NET page in your project where you’d like to insert the reCAPTCHA control
6. Register the user control in the header of the page (or via your web.config if you like keeping your control registry centralised)

7. Add the control to your web page

8. Replace the public and private key placeholders with those obtained from the previous step

9. Run the project and navigate to the URL where the control was inserted and you’ll see the control appear.So now it’s rendering within your HTML the next step is to check if the user has entered in the valid words so.

10. In your code-behind page, or wherever you’re performing the page validation, you simply need to check the Page.IsValid property.  If it’s “false” the words were entered incorrectly, an alternatively if it’s “true” then the user entered them correctly.

Personally I’d prefer the control exposed a property that performed the aforementioned action but still it’s not bad for a free control that can be implemented in a matter of minutes.

There are a few options available with regards to the controls appearance, preferred language, tabindex etc. which you can read more about here: Customizing the Look and Feel of reCAPTCHA

Good luck.