Update:
Ben,
The proposed solution works only with Owin. To get it working in an MVC application you have to use asp.net MVC 6 (part of asp.net core or asp.net 5) only. But, with Web API you can use the older versions too. To setup the application please use the following steps:
Create an empty project using visual studio templates(don't select Web API or MVC)
Add the following Nuget packages to the project:
Microsoft.AspNet.WebApi
Microsoft.AspNet.WebApi.Owin
Microsoft.Owin.Host.SystemWeb
Microsoft.Owin.StaticFiles
Add a Startup.cs file and decorate the namespace with the following
[assembly: OwinStartup(typeof(Startup))]
Add the following code to the Stratup.cs class
public void Configuration(IAppBuilder app)
{
var config = new HttpConfiguration();
config.MapHttpAttributeRoutes();
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}",
defaults: new {id = RouteParameter.Optional}
);
//Configure the file/ static file serving middleware
var physicalFileSystem = new PhysicalFileSystem(@".\client");
var fileServerOptions = new FileServerOptions
{
EnableDefaultFiles = true,
RequestPath = PathString.Empty,
FileSystem = physicalFileSystem
};
fileServerOptions.DefaultFilesOptions.DefaultFileNames = new[] {"index.html"};
fileServerOptions.StaticFileOptions.ServeUnknownFileTypes = true;
fileServerOptions.StaticFileOptions.FileSystem = physicalFileSystem;
app.UseFileServer(fileServerOptions);
app.UseWebApi(config);
}
- This should do the magic. Now you can host the application in IIS. IIS will serve the static assets only from client folder. Add Server folder and add controllers.
The Microsoft.Owin.Host.SystemWeb is what facilitates the hosting of Owin application in IIS. The file serve options help IIS to serve static files only from client folder.
Please let me know if you have any questions.
Based on your question, the project structure that you want to achieve should be like the following.

Basically you will have two folders only, Client and Server. Static files are served from client folder only. Server folder is not accessible. If this is what you need then it can be achieved easily with Owin Self Host with Static File Serving middleware.
Self host works with out any dependency on IIS. But, if your planning to host this application on Linux, you could use Asp.NET CORE 1.0. Later if you decide to host the application on IIS inside windows that can be achieved easily by adding the Microsot.Owin.Host.SystemWeb nuget package.
There are great blog posts on this topic. This is the link for one of them. Here is the link for achieving the same in Asp.NET Core.
I hope this solves your issues and please let me know if you have any questions.
Thank you,
Soma.