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.Extensions.DependencyInjection;

namespace WebApplication1
{
     public class Startup
     {
          // This method gets called by the runtime. Use this method to add services to the container.
          // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
          public void ConfigureServices(IServiceCollection services)
          {
          }

          // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
          public void Configure(IApplicationBuilder app, IHostingEnvironment env)
          {
               if (env.IsDevelopment())
               {
                    app.UseDeveloperExceptionPage();
               }

               app.Run(async (context) =>
               {
                    await context.Response.WriteAsync("Hello World!");
               });
          }
     }
}

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;

namespace WebApplication1
{
     public class Program
     {
          public static void Main(string[] args)
          {
               CreateWebHostBuilder(args).Build().Run();
          }

          public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
               WebHost.CreateDefaultBuilder(args)
                    .UseStartup<Startup>();
     }
}