Question

I am a beginner in Asp.Net MVC3. Can anybody please explain what is meant by this code:

@section head
{
    @RenderSection("head", false)
}

On ScottGu’s article:

http://weblogs.asp.net/scottgu/archive/2010/12/30/asp-net-mvc-3-layouts-and-sections-with-razor.aspx

there is an example of RenderSection but it defines @section and then somewhere @RenderSection is used. In this case section head is defined and within that itself the same head is being rendered which confused me.

What does RenderSection do and how do I find what is being rendered here?

Answer 1

Scott wrote at one point

The first parameter to the “RenderSection()” helper method specifies
the name of the section we want to render at that location in the
layout template. The second parameter is optional, and allows us to
define whether the section we are rendering is required or not. If a
section is “required”, then Razor will throw an error at runtime if
that section is not implemented within a view template that is based
on the layout file (which can make it easier to track down content
errors).

So, what RenderSection does, is rendering a section defined in the template/view (not the general _Layout).
A little bit furtherdown under “Implementing the “SideBar” Section in our View Template” he explains how to implement a section.

So all in all, what you have is a section called “head” that renders a section called “head” in a view that’s further down/nested.

Edit: have a look at http://blogs.msdn.com/b/marcinon/archive/2010/12/15/razor-nested-layouts-and-redefined-sections.aspx to see what I mean with nested views – but note that this article is over a year old now.

MasterLayout:

@RenderSection("head", false)

SubLayout:

@{
    Layout = "~/Views/_MasterLayout.cshtml";
}
@section head
{
    @RenderSection("head")
}

Content:

@{
    Layout = "~/Views/_SubLayout.cshtml";
}
@section head
{
    <title>Content-Layout</title>
}