.Net5：如何从Program.cs获取EnvironmentName

问题描述

以下代码在NetCore 3.1中可以很好地工作，但在.Net5中不起作用

var webHostBuilder = WebHostBuilder(args);
var environment = webHostBuilder.GetSetting("environment");

解决方法

使用 GetService

using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

namespace WebApplication1
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var hostBuilder = CreateHostBuilder(args).Build();
            var hostEnvironment = hostBuilder.Services.GetService<IHostEnvironment>();

            // Get EnvironmentName
            var environment = hostEnvironment?.EnvironmentName; // Possible values: Development,Production,CustomEnvironment,etc..

            hostBuilder.Run();
        }

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                });
    }
}