问题
Does anyone have any recommendations for CAPTCHA components for use in ASP.NET projects?
回答1:
I've been using recaptcha for a couple of sites with great success. I really recommend it.
There is a recaptcha control for asp.net here.
I've also used this captcha with success.
回答2:
Before you evaluate any captcha solutions you should develop a clear profile of your users. Needless to say, any captcha solution is going to make your site harder to use. If your users are older with vision difficulties deciphering a captcha can be extremely difficult if not impossible. Random characters vs real words, may impact your users. Native language may affect user's perception of what the character represents (special characters).
No recommendations here, but knowing your users and what they will tolerate and or are capable of, should have a significant impact on your decision.
回答3:
How about BotDetect?
The free version is available as well while they don't force your visitors to solve 2 captcha words.
回答4:
I would second the Mondor's Captcha mentioned in the first answer. Unlike the reCaptcha, it is fully independent, you don't make a call to other website. Also, it allows asking for solving a simple equation (like "5 + 3") and while bots would answer "5+3", human would answer 8. Also, unlike the reCaptcha, you can customize it as much as you want and include your own alphabet (Cyrillic, Arabic, Chinese - whatever).
回答5:
Recaptcha is a nice captcha to protect your forms if you want to take a dependency on Google.
Telerik has a great ASP.Net captcha control available that you should check out as well.
回答6:
I am also using the recaptcha, and it is great!
Here is the link for the ASP.NET plugin/wrapper:
Using reCAPTCHA with ASP.NET
回答7:
You could try Picatcha - pretty cool to use and looks easy to implement. Images vs text. Fairly customisable
回答8:
If you're using VB.NET as your base language (or even Classic ASP), I just found a great free CAPTCHA at TipsTrips.org. You customize the CAPTCHA you want and then download the code. The .NET download includes a ASHX handler file, two VB class files and an ASPX test page.
来源：https://stackoverflow.com/questions/696398/what-is-the-best-recommended-captcha-component-for-asp-net