public static IWebHost BuildWebHost(string[] args) =>

            WebHost.CreateDefaultBuilder(args)   //这句代码默认使用了Kestrel F12查看源,如下:

                .UseUrls("http://*:8080";)

                .UseStartup<Startup>()

                .Build();

        // 备注:

        //     The following defaults are applied to the returned Microsoft.AspNetCore.Hosting.WebHostBuilder:

        //     use Kestrel as the web server, set the Microsoft.AspNetCore.Hosting.IHostingEnvironment.ContentRootPath

        //     to the result of System.IO.Directory.GetCurrentDirectory, load Microsoft.Extensions.Configuration.IConfiguration

        //     from 'appsettings.json' and 'appsettings.[Microsoft.AspNetCore.Hosting.IHostingEnvironment.EnvironmentName].json',

        //     load Microsoft.Extensions.Configuration.IConfiguration from User Secrets when

        //     Microsoft.AspNetCore.Hosting.IHostingEnvironment.EnvironmentName is 'Development'

        //     using the entry assembly, load Microsoft.Extensions.Configuration.IConfiguration

        //     from environment variables, load Microsoft.Extensions.Configuration.IConfiguration

        //     from supplied command line args, configures the Microsoft.Extensions.Logging.ILoggerFactory

        //     to log to the console and debug output, enables IIS integration, enables the

        //     ability for frameworks to bind their options to their default configuration sections,

        //     and adds the developer exception page when Microsoft.AspNetCore.Hosting.IHostingEnvironment.EnvironmentName

        //     is 'Development'

        public static IWebHostBuilder CreateDefaultBuilder(string[] args);