ASP.net core MVC catch all route serve static file

Question

Is there a way to make a catch all route serve a static file?

Looking at this http://blog.nbellocam.me/2016/03/21/routing-angular-2-asp-net-core/

I basically

Answer 1

In order to serve index.html from wwwroot folder the following directives should be added (.Net Core 2).

This allows to serve static files:

app.UseStaticFiles();

This allows to get default files, e.g. index.html:

app.UseDefaultFiles();

Answer 2

In ASP.NET Core 3.1, I've used the following:

Startup.cs

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    app.UseRouting();

    app.UseCors();

    app.UseEndpoints(endpoints =>
    {
        endpoints.MapControllers();
    });

    app.UseDefaultFiles();
    app.UseStaticFiles();
}

MyController.cs

[HttpGet("{anything}")]
public IActionResult GetSPA()
{
    return File("~/index.html", "text/html");
}

Answer 3

In case you don't want manually specify which routes are for api:

app.UseDefaultFiles();
app.UseStaticFiles();

app.UseMvc() // suggestion: you can move all the SPA requests to for example /app/<endpoints_for_the_Spa> and let the mvc return 404 in case <endpoints_for_the_Spa> is not recognized by the backend. This way SPA will not receive index.html

// at this point the request did not hit the api nor any of the files

// return index instead of 404 and let the SPA to take care of displaying the "not found" message
app.Use(async (context, next) => {
    context.Request.Path = "/index.html";
    await next();
});
app.UseStaticFiles(); // this will return index.html

Answer 4

ASP.NET Core catch all routes for Web API and MVC are configured differently

With Web API (if you're using prefix "api" for all server-side controllers eg. Route("api/[controller"]):

app.Use(async (context, next) => 
{ 
    await next(); 
    var path = context.Request.Path.Value;

    if (!path.StartsWith("/api") && !Path.HasExtension(path)) 
    { 
        context.Request.Path = "/index.html"; 
        await next(); 
    } 
});            

app.UseStaticFiles();
app.UseDefaultFiles();

app.UseMvc();

With MVC (dotnet add package Microsoft.AspNetCore.SpaServices -Version x.y.z):

app.UseStaticFiles();
app.UseDefaultFiles();

app.UseMvc(routes => 
{ 
    routes.MapRoute( 
        name: "default", 
        template: "{controller=Home}/{action=Index}"); 

    routes.MapSpaFallbackRoute("spa", new { controller = "Home", action = "Index" }); 
});  

Answer 5

If you're already in the routing stage, you've gone past the point where static files are served in the pipeline. Your startup will look something like this:

app.UseStaticFiles();

...

app.UseMvc(...);

The order here is important. So your app will look for static files first, which makes sense from a performance standpoint - no need to run through MVC pipeline if you just want to throw out a static file.

You can create a catch-all controller action that will return the content of the file instead. For example (stealing the code in your comment):

public IActionResult Spa()
{
    return File("~/index.html", "text/html");
}

Answer 6

I had to make some additions to @DavidG answer. Here is what I ended up with

Startup.cs

app.UseStaticFiles();

app.UseMvc(routes =>
{
   routes.MapRoute("default", "{controller}/{action}");

   routes.MapRoute("Spa", "{*url}", defaults: new { controller = "Home", action = "Spa" });
});

HomeController.cs

public class HomeController : Controller
{
  public IActionResult Spa()
  {
      return File("~/index.html", "text/html");
  }
}