ASP .NET CORE 读取配置文件的方法

{
  "Logging": {
    "IncludeScopes": false,
    "LogLevel": {
      "Default": "Warning"
    }
  },
  "Wizards": [
    {
      "Name": "Gandalf",
      "Age": "1000"
    },
    {
      "Name": "Harry",
      "Age": "17"
    }
  ],
  "Sex": {
    "Man": 0,
    "Female": 1
  }
}

            var builder = new ConfigurationBuilder()
           .SetBasePath(Directory.GetCurrentDirectory())
           .AddJsonFile("appsettings.json");
            var config = builder.Build();
            var ret = config.GetSection("Sex:Man").Value;