MVC converts randomly generated strings to pictures

The original: MVC converts randomly generated strings into pictures

Insus.net in this article "randomly get a string in an ASP. http://www.cnblogs.com/insus/p/3619224.html, just produce a random string," So how do we make it happen? Is it a picture?
There is no relationship, Insus.net church everyone to achieve it.

If your site is still an application, or ASP, non-MVC, you can refer to the following two links:
"Implement string to Picture" http://www.cnblogs.com/insus/archive/2009/03/08/1406122.html this is a video.

Another article, "Text creation picture, aspx to ascx value" http://www.cnblogs.com/insus/archive/2013/03/08/2950300.html.

In an ASP. NET MVC application, you can first create a defined result:

In the controller, create a two action:

To create a view:

Demonstrate: