配置文件帮助类 Core 3.0

    public class AppSetting
    {
        static IConfiguration Configuration { get; set; }

        public static bool ReloadOnChange { get; set; }


        /// <summary>
        /// 初始化配置文件路径
        /// </summary>
        //static AppSetting() 
        //{
        //    ReloadOnChange = true;
        //    Configuration = new ConfigurationBuilder().
        //        Add(new JsonConfigurationSource { Path = "appsettings.json", ReloadOnChange = ReloadOnChange }).Build();
        //}

        static AppSetting()
        {
            //动态根据环境变量不同，获取配置文件
            //string path = $"Appsettings.{Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT")}.json";
            //appsettings.json一定要在输出目录
            string path = "Appsettings.json";

            //Configuration = new ConfigurationBuilder().
            //    Add(new JsonConfigurationSource { Path = path, ReloadOnChange = true }).Build();

            //直接获取当前启动项的根目录appsetting.json文件。

            Console.WriteLine(Directory.GetCurrentDirectory());
            Configuration = new ConfigurationBuilder().SetBasePath(Directory.GetCurrentDirectory()).
                Add(new JsonConfigurationSource { Path = path, ReloadOnChange = true }).Build();

        }
        public static string app(params string[] sections) 
        {
            try
            {
                var val = string.Empty;
                for (int i = 0; i < sections.Length; i++)
                {
                    val += sections[i] + ":";
                }
                return Configuration[val.TrimEnd(‘:‘)];
            }
            catch 
            {
                return "";
            }
        }

        public static T GetSession<T>(string sessionName) where T:class
        {
            if (string.IsNullOrEmpty(sessionName))
                return null;
            var result = Configuration.GetSection(sessionName).Get<T>();
            return result;
        }


    }