Introduction to solutions implemented by CAPTCHA in Asp.net

Implement CAPTCHA in Asp.netArticleThere are already many online solutions that are mature:

 

1. An open-source control written in VB:

Http://www.codeproject.com/KB/custom-controls/CaptchaControl.aspx

 

2. Implement the CAPTCHA control in CSHARP. The basic idea is to use bitmap to "Draw" the text and then use hatchbrush to add some points.

Http://www.codeproject.com/KB/aspnet/CaptchaImage.aspx

 

3. The following is the same author as the first author, but it is implemented using CSHARP:

Http://captcha.codeplex.com/SourceControl/changeset/view/1478#31243

 

4. The most widely used ones should be:

Http://www.google.com/recaptcha

Its Asp.net plug-in can be downloaded from here:

Http://code.google.com/apis/recaptcha/docs/aspnet.html

The above is also a detailed description of how to use it.

 

Remember to replace the public key and private key.

This plug-in also provides completely personalized interfaces. The only pity is that many times, the images it generates are not very clear-this is related to the idea of the creative team at the beginning-they want users to constantly improve their text recognition systems.