Create a new solution and choose the ASP.NET MVC 3 Web Application, Internet Application (forms authentication) and Razor view engine with HTML5 semantic markup.

Let’s now create an HTML view to upload one or more files. Select the Views solution folder in the Solution Explorer window, create a new Razor view page, and add the following code to it.

Last time, we looked at the basics of tag helpers in ASP.NET MVC 6 and I showed how to create one. Let's dig a bit deeper this time, and now I'll show how to create a custom tag helper that loads a ...