要在Asp.Net Core中创建对象特定的子路由，可以使用路由属性和区域来实现。以下是一个示例：

1. 首先，创建一个控制器类，例如“HomeController”：

using Microsoft.AspNetCore.Mvc;

namespace YourNamespace.Controllers
{
    [Route("api/[controller]")]
    public class HomeController : Controller
    {
        [HttpGet]
        public IActionResult Get()
        {
            return Ok("Home Get");
        }

        [HttpGet("about")]
        public IActionResult About()
        {
            return Ok("Home About");
        }
    }
}

2. 在Startup.cs文件中配置路由和区域：

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

namespace YourNamespace
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);
        }

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

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

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

                routes.MapRoute(
                    name: "areas",
                    template: "{area:exists}/{controller=Home}/{action=Index}/{id?}");
            });
        }
    }
}

3. 在项目中创建一个区域文件夹，例如“Areas”文件夹，并在其中创建一个区域类，例如“AdminArea”：

using Microsoft.AspNetCore.Mvc;

namespace YourNamespace.Areas.AdminArea
{
    [Area("AdminArea")]
    [Route("api/[area]/[controller]")]
    public class AdminController : Controller
    {
        [HttpGet]
        public IActionResult Get()
        {
            return Ok("Admin Get");
        }

        [HttpGet("dashboard")]
        public IActionResult Dashboard()
        {
            return Ok("Admin Dashboard");
        }
    }
}

4. 现在，可以通过以下URL访问相应的控制器动作：

• /api/home - Home Get
• /api/home/about - Home About
• /api/adminarea/admin - Admin Get
• /api/adminarea/admin/dashboard - Admin Dashboard

通过使用路由属性和区域，可以在Asp.Net Core中创建对象特定的子路由。