Startup.cs UseSpaStaticFiles and UseSpa

Startup.cs

app.UseSpaStaticFiles();

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

app.UseSpa(spa =>
{
    // To learn more about options for serving an Angular SPA from ASP.NET Core,
    // see https://go.microsoft.com/fwlink/?linkid=864501

    spa.Options.SourcePath = "ClientApp";

    if (env.IsDevelopment())
    {
        spa.UseAngularCliServer(npmScript: "start");
    }
});