ASP.Net核心5.0中的子域路由

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Routing;
using Microsoft.Extensions.DependencyInjection;

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddControllersWithViews();
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        else
        {
            app.UseExceptionHandler("/Home/Error");
            app.UseHsts();
        }

        app.UseHttpsRedirection();
        app.UseStaticFiles();

        app.UseRouting();

        app.UseAuthorization();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllerRoute(
                name: "default",
                pattern: "{controller=Home}/{action=Index}/{id?}");
        });

        // 子域路由配置
        var subdomainRoutes = new Route(
            "subdomain",
            "https://{subdomain}.example.com/{controller}/{action}/{id?}",
            new { controller = "Subdomain", action = "Index" },
            new SubdomainRouteConstraint());

        app.UseRouting(subdomainRoutes);
    }
}

public class SubdomainRouteConstraint : IRouteConstraint
{
    public bool Match(
        HttpContext? httpContext,
        IRouter? route,
        string routeKey,
        RouteValueDictionary values,
        RouteDirection routeDirection)
    {
        if (httpContext?.Request == null || httpContext.Request.Host == null)
        {
            return false;
        }

        var host = httpContext.Request.Host.Host;
        if (host.EndsWith(".example.com"))
        {
            values["subdomain"] = host.Substring(0, host.Length - ".example.com".Length);
            return true;
        }

        return false;
    }
}

public class SubdomainController : Controller
{
    public IActionResult Index(string subdomain)
    {
        return View((object)subdomain);
    }
}