NETCore 读取配置文件

        /// <summary>
        /// Core 读取配置文件
        /// 1. Microsoft.Extensions.Configuration;
        /// 2. Microsoft.Extensions.Configuration.Json;
        /// 3.
        /// </summary>
        /// <param name="key"></param>
        /// <returns></returns>
        public static string GetConfig(string key)
        {
            var builder = new ConfigurationBuilder().AddJsonFile("appsettings.json");//配置文件名称
            IConfigurationRoot root = builder.Build();
            string Valuestr=root.GetSection(key).Value;
            return Valuestr;
        }