Why do HtmlHelpers need an argument to this HtmlHelper helper?

Question

Why do HtmlHelpers need to be declared with an argument to an HtmlHelper helper?

i.e

public static string ScheduleEntries(this HtmlHelper helper, ...)

I've never noticed that syntax before in C#, what is it called?

Thanks

-Matt

Answer 1

That's an extension method.

The way it works for MVC is that Html in the view is a property of HtmlHelper type on the ViewPage class.