从 appsettings.json 配置文件中读取

Question

I have the following config in my appsettings.json File

 {
  "AppSettings": {
    "MainUser": {
      "Name": "Urs",
      "Surname": "Barandun",
      "SesstionTimeInMin": "30",
    }
  },

And I'd like to create a custom configuration class and bind it. Eg:

MainUserConfiguration mainUserConfiguration = new MainUserConfiguration();
var configSection = config.GetSection("MainUserConfiguration");
configSection.Bind(mainUserConfiguration);

But, my code does not work. :/

Answer 1

Based on what you've provided, your appsettings file and the nested JSON for your configuration don't match up. A typical ASP.NET Core appsettings.json doesn't have a nested element called "AppSettings", and further you're getting a configuration section called "MainUserConfiguration" while your actual JSON just names that section "MainUser".

appsettings example:

{
  "MyFirstClass": {
    "Option1": "some string value",
    "Option2": 42
  },
  "MySecondClass": {
    "SettingOne": "some string value",
    "SettingTwo": 42
  }
}

In your code:

public class MyFirstClass
{
    public string Option1 { get; set; }
    public int Option2 { get; set; }
}

public class MySecondClass
{
    public string SettingOne { get; set; }
    public int SettingTwo { get; set; }
}

In your Startup.cs (presuming that's where you're accessing it with a defined Configuration object:

var myFirstClass = Configuration.GetSection("MyFirstClass").Get<MyFirstClass>();
var mySecondClass = Configuration.GetSection("MySecondClass").Get<MySecondClass>();
Console.WriteLine($"The answer is always {myFirstClass.Option2}");

Answer 2

try this inside of startup

var appSettingsUserSection = configuration.GetSection("AppSettings:MainUser");

    services.Configure<MainUser>(appSettingsUserSection);

    var settings = appSettingsUserSection.Get<MainUserSettings>();
     var name=settings.Name; //Urs

class

public class MainUserSettings
{
    public string Name { get; set; }
    public string Surname { get; set; }
    public int SesstionTimeInMin { get; set; }
}

now you can use it any class using code like this, in controller for example

public class MyController:Controller
    {
        private readonly IOptions<MainUserSettings> _userSettings;

        public MyController (IOptions<MainUserSettings> userSettings)
        {
            _userSettings = userSettings;
        }

        public  IActionResult MyAction()
        {
            var name=_userSettings.Name; //Urs
        }
}