Startup.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using IHostingEnvironment = Microsoft.AspNetCore.Hosting.IHostingEnvironment;
using static APICore.Models.appSetting;
using Swashbuckle.AspNetCore.SwaggerUI;
using APICore.Models;
using APICore.Common;
using APICore.dbContext;

namespace APICore
{
    public class Startup
    {
        public Startup(IHostingEnvironment env)
        {
            //List<string> LFile = Directory.GetFiles(@"../Services.Common/").ToList();
            //string filename = LFile.Where(t => t.Contains("appsetting.json")).FirstOrDefault();
            //FileInfo info;
            //info = new FileInfo(filename);

            var builder = new ConfigurationBuilder()
                .SetBasePath(env.ContentRootPath)
                //.AddJsonFile(path: info.FullName, optional: true, reloadOnChange: true);
                .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
                .AddJsonFile("appsettings.json");

            Configuration = builder.Build();
        }

        public IConfiguration Configuration { get; }
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers()
                    .AddNewtonsoftJson(options =>
                    options.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore);

            services.Configure<StateConfigs>(Configuration.GetSection("StateConfigs"));

            services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();

            services.ConfigureSwagger();
        }
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseHttpsRedirection();

            // app.UseSwagger();
            app.UseSwagger(e => e.SerializeAsV2 = true);
            app.UseSwaggerUI(c =>
            {
                c.SwaggerEndpoint("v2/swagger.json", "MyAPI V1");
            });
            app.UseRouting();

            app.UseAuthorization();

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