【二】、.net core 3.1 windows服务读取appsetting的步骤

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "MQ": {
    "IP": "127.0.0.1",
    "Port": "61616",
    "UserName": "admin",
    "Password": "admin"
  }
}

    public class MQConfig
    {
        public string IP { get; set; }
        public string Port { get; set; }
        public string UserName { get; set; }
        public string Password { get; set; }
    }

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
            .UseWindowsService()
            .ConfigureServices((hostContext, services) =>
                {
                    services.AddHostedService<Worker>();
                    services.Configure<MQConfig>(hostContext.Configuration.GetSection(key: "MQ"));
                })
            .UseSerilog();

    public class Worker : BackgroundService
    {
        private readonly ILogger<Worker> _logger;
        private readonly MQConfig _mqConfig;

        public Worker(ILogger<Worker> logger, IOptions<MQConfig> settings)
        {
            _logger = logger;
            _mqConfig = settings.Value;
        }

        protected override async Task ExecuteAsync(CancellationToken stoppingToken)
        {
            while (!stoppingToken.IsCancellationRequested)
            {
                _logger.LogInformation("Worker running at: {time}" + "IP:{1},Port:{2}", DateTimeOffset.Now, _mqConfig.IP, _mqConfig.Port);
                await Task.Delay(1000, stoppingToken);
            }
        }
    }