手动读取配置文件appsettings.json

在代码中手动读取配置文件 ：

 //在代码中手动读取配置文件
    public class ReadConfig
    {
        /// <summary>
        /// 读取配置文件,默认读：appsettings.json
        /// </summary>
        /// <param name="nodeName">节点，多层节（ConnectionStrings:RedisConnection)</param>
        /// <param name="configFileName">配置文件名，默认：appsettings.json</param>
        /// <returns></returns>
        public static string Read(string nodeName, string? configFileName = "appsettings.json")
        {
            ConfigurationBuilder configBuilder = new ConfigurationBuilder();
            configFileName = string.IsNullOrEmpty(configFileName) ? "appsettings.json" : configFileName;
            configFileName = configFileName.Contains(".json") ? configFileName : $"{configFileName}.json";
            configBuilder.AddJsonFile(configFileName.Trim(), optional: false, reloadOnChange: true);
            IConfiguration config = configBuilder.Build();
            string value = config[nodeName.Trim()];
            return value;
        }
    }

　　依赖开发包：Microsoft.Extensions.Configuration，Microsoft.Extensions.Configuration.Json