asp.net核心2.1 ConfigurationBuilder GetSection函數返回null

Question

ConfigurationBuilder Getsection（）在.net core 2.1控制台應用程序上返回null。 我已經搜索了不少博客和帖子，但有json示例，其嵌套高達3-4級。

動機是閱讀json及其元素的整個“測試”鍵並進行操作。 我希望這個json可以在應用程序之外進行配置，因此可以在不對代碼進行任何更改的情況下對其進行更改。 下面是示例代碼

{
  "test": {
    "test1": {
      "testing": {
        "ApplicationName": "Microsoft Visual Studio", 
        "appid": "123456", 
        "ApplicationProfile": {
          "Vs2015": "Microsoft Visual Studio 2015 Professional",
          "VS_2017_Restricted": "Microsoft Visual Studio 2017 Enterprise (Restricted)"
        }
      }
      },
      "Applications": {
        "app1": {
          "Name": "application1",
          "arrayOfSomething": [ "first array elment", "Secondarrayelement" ],
          "anotherarraylikeabove": [],

        },
        "app2": {
          "Name": "application2",
          "Softwares": [ "first array elment", "second element" ],
          "APACGroups": [],
          "EMEA": [],
          "OnlyForZurich": [] 
        }
      }
    }
  }
}

var builder = new ConfigurationBuilder()
                .SetBasePath(Directory.GetCurrentDirectory())
                .AddJsonFile("appSettings.json", optional: true, reloadOnChange: true);
IConfigurationRoot configuration = builder.Build();
var test  = configuration.GetSection("app2"); //test is null always

Answer 1

使用這個可能它的工作：

JSON：

   "Locations": {
        "Location": [ "Ford", "BMW", "Fiat" ]
    },

啟動：

 // Replace IConfiguration with IHostingEnvironment since we will build
    // Our own configuration
    public Startup(IHostingEnvironment env)
    {
        var builder = new ConfigurationBuilder()
            .SetBasePath(env.ContentRootPath)
            .AddEnvironmentVariables()
            .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
            .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true);

        // Set the new Configuration
        Configuration = builder.Build();
    }

並從以下數據獲取數據

 public IActionResult Settings()
    {
       var array = Configuration.GetSection("Locations:Location")
           .GetChildren()
           .Select(configSection => configSection.Value);
       return View();
    }