In ASP.NET MVC3 “master pages” are handled in the _ViewStart.cshtml file. As the name suggests the code in this file is
executed before each view is rendered (see Scott Gu’s blog post (http://weblogs.asp.net/scottgu/archive/2010/10/22/asp-net-mvc-3-layouts.aspx)
for more details).
Now that you understand the basic use of _ViewStart.cshtml
file lets go over the scope applied to these files. The _ViewStart.cshtml file will affect all views
in the same directory and below the location of it. Also you can have another _ViewStart.cshtml
file under a sub-folder which will be executed after the top level
_ViewStart.cshtml. Using this feature
you can in effect override the top level _ViewStart.cshtml with one closer to
the view.
Now when the Index.cshtml
View under the Home folder is rendered, it will first execute the
/Views/_ViewStart.cshtml file and then it will render the Index.cshtml
View.
However, when the Index.cshtml
View under the DifferentMasterPage folder is rendered, it will
first execute the /Views/_ViewStart.cshtml file, then it will execute
the /Views/DifferentMasterPage/_ViewStart.cshtml file, and then it will
render the Index.cshtml View.
