AssemblyInfo versioning ignored in ASP.NET MVC Web App?

The view is (by default) still largely compiled on-demand, so you con't reliably use GetExecutingAssembly() within the view - however, for me the controller usage works fine:

[assembly: AssemblyVersion("1.2.3.4")]

with:

<h2><%=typeof(MvcApplication4.Controllers.HomeController).Assembly
   .GetName().Version.ToString() %></h2>

shows

1.2.3.4

edit The mistake you made was calling typeof(...).GetType() - that is going to give you Type (or a subclass) - so yes, it will be 2.x. /edit

For the extra step of pre-compiling the views, see "MSBuild Task for Compiling Views" here.

Arguably, your view shouldn't be fetching this data itself anyway - it should be put into the ViewData (or similar), perhaps by a base-controller or action-filter.

Re the question about master pages; first, pick a key ;-p

<%=ViewData["AppVersion"] %>

then two options leap to mind: override OnActionExecuting in the controller (or a common base-controller):

    protected override void OnActionExecuting(
        ActionExecutingContext filterContext)
    {
        filterContext.Controller.ViewData["AppVersion"] =
            GetType().Assembly.GetName()
            .Version.ToString(); // probably cached
        base.OnActionExecuting(filterContext);
    }

or create an action-filter:

public class AppVersionAttribute : ActionFilterAttribute
{
    public override void OnActionExecuting(
         ActionExecutingContext filterContext)
    {
        filterContext.Controller.ViewData["AppVersion"] =
            GetType().Assembly.GetName()
            .Version.ToString(); // probably cached
        base.OnActionExecuting(filterContext);
    }
}

And mark your controllers (classes) or actions (methods) with this attribute:

[HandleError, AppVersion]
public class HomeController : Controller
{ ... }