为什么未应用api版本？

我有以下代码Statup.cs来设置带有多种版本的Web API。问题是未使用该版本-请参见下面的屏幕截图。

我在配置选项中确实使用了AddApiVersioning ..以及UrlSegmentApiVersionReader作为ApiVersionReader。

我想念什么？

我使用的框架是.NetCore 3.0。

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Versioning;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.OpenApi.Models;
using System;
using System.IO;
using System.Reflection;

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

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            // Register the Swagger generator, defining 1 or more Swagger documents
            services.AddSwaggerGen(c =>
            {
                c.SwaggerDoc("v1", new OpenApiInfo
                {
                    Title = "Employee API",
                    Version = "v1",
                    Description = "An API to perform Employee operations",
                    TermsOfService = new Uri("https://example.com/terms"),
                    Contact = new OpenApiContact
                    {
                        Name = "John Walkner",
                        Email = "[email protected]",
                        Url = new Uri("https://twitter.com/jwalkner"),
                    },
                    License = new OpenApiLicense
                    {
                        Name = "Employee API LICX",
                        Url = new Uri("https://example.com/license"),
                    }
                });

                c.SwaggerDoc("v2", new OpenApiInfo
                {
                    Title = "Employee API",
                    Version = "v2",
                    Description = "An API to perform Employee operations",
                    TermsOfService = new Uri("https://example.com/terms"),
                    Contact = new OpenApiContact
                    {
                        Name = "John Walkner",
                        Email = "[email protected]",
                        Url = new Uri("https://twitter.com/jwalkner"),
                    },
                    License = new OpenApiLicense
                    {
                        Name = "Employee API LICX",
                        Url = new Uri("https://example.com/license"),
                    }
                });

                // Set the comments path for the Swagger JSON and UI.
                var xmlFile = $"{Assembly.GetExecutingAssembly().GetName().Name}.xml";
                var xmlPath = Path.Combine(AppContext.BaseDirectory, xmlFile);
                c.IncludeXmlComments(xmlPath);
            });

            services.AddControllers();

            services.AddApiVersioning(o => {
                o.ReportApiVersions = true;
                o.AssumeDefaultVersionWhenUnspecified = true;
                o.DefaultApiVersion = new ApiVersion(1, 0);
                o.ApiVersionReader = new UrlSegmentApiVersionReader();
            });
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            app.UseStaticFiles();

            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseHttpsRedirection();

            app.UseRouting();

            app.UseAuthorization();

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

            // Enable middleware to serve generated Swagger as a JSON endpoint.
            app.UseSwagger(x => x.SerializeAsV2 = true);

            // Enable middleware to serve swagger-ui (HTML, JS, CSS, etc.),
            // specifying the Swagger JSON endpoint.
            app.UseSwaggerUI(c =>
            {
                c.SwaggerEndpoint("/swagger/v1/swagger.json", "My API V1");
                c.SwaggerEndpoint("/swagger/v2/swagger.json", "My API V2");
            });
        }
    }
}