Core.AspNet.Web.Hosting.Kestrel 1.0.0.26263

Core.AspNet.Web.Hosting.Kestrel

Start here. Hosts a classic ASP.NET application — WebForms, MVC, Razor, Web Pages, Web API — on .NET 10 under Kestrel, instead of IIS.

<PackageReference Include="Core.AspNet.Web.Hosting.Kestrel" Version="1.0.0" />

using Microsoft.AspNetCore.Builder;
using System.Web.Hosting.Kestrel;

var builder = WebApplication.CreateBuilder (args);
var app = builder.Build ();

app.UseStaticFiles ();          // before UseWebForms, so Kestrel serves css/js/images directly

app.UseWebForms (options => {
    options.PhysicalPath = app.Environment.ContentRootPath;   // the directory holding web.config
    options.VirtualPath  = "/";
    options.SiteName     = "MyApp";
});

app.Run ();

That is the whole host, whatever stack the application uses. Your .aspx, .ascx, .master, .cshtml, code-behind, controllers and web.config stay as they are, and namespaces are unchanged — System.Web.UI.Page is still System.Web.UI.Page.

What comes with it

Core.AspNet.Web.Forms, Core.AspNet.Configuration, Core.AspNet.Web.Services, Core.AspNet.Web.Extensions and Core.AspNet.Web.ConfigBridge arrive transitively. Add one more package per stack you use — MVC, Web Pages, Web API, WCF, bundling, out-of-process session state.

Two build assets are imported automatically:

• WebFormsPort.targets — removes the empty .NET System.Web.dll / System.Configuration.dll facades. Not optional: without it they collide with the port, giving CS0433 at build time and TypeLoadException on the first request. It also asserts that Core.Web.dll reached your output directory, turning that runtime failure into a build error.
• Project-tree nesting — puts Default.aspx.cs and Default.aspx.designer.cs under Default.aspx in Solution Explorer, for .aspx, .ascx, .master, .ashx, .asmx and .asax, in C# and VB.

Options

Things that bite

• Order matters. UseWebForms handles everything by default and lets <httpHandlers> and the route table decide the outcome — including 403 for .cs/.config. Anything you want handled outside System.Web goes before it.
• One application per process. There is no AppDomain and no app-pool equivalent.
• App_Code is compiled at runtime, so your project must <Compile Remove="App_Code\**\*.cs" /> and ship it as content instead.
• Assembly names in web.config change. assembly="System.Web" becomes assembly="Core.Web"; left alone it binds to the empty framework facade and the registration is silently dropped.

Documentation

PORTING-GUIDE.md (step-by-step migration from IIS) and LIMITATIONS.md (what differs from ASP.NET on .NET Framework, and why) ship in the repository.

Licence

MIT, as the upstream Mono sources this is built from and the code written for this port. THIRD-PARTY-NOTICES.md ships in the package and says which part is which.