如何使用值数组读取appsettings.json

Question

I have the following appSettings.json file:

  "SundrySettings": {

    "CookieName": "Cookie",

    "AccessGroup": "Software Development",

    "Terminals" :  {
      "Raucherplatz" : "tablet1.local",
      "Service" :      "tablet2.local",  
      "Technik" :      "tablet3.local",  
      "Technik" :      "tablet4.local",  
      "Container" :    "tablet5.local"
    }
  }
}

That I would like to load into the following structure:

    public class Terminal
    {
        public string Name;
        public string Description;
    }

    public class SundryOptions
    {
        public string CookieName { get; set; } = "dummy";
        public string HRAccessGroup { get; set; } = "dummy";
        public List<Terminal> Terminals;
    }

that I would try to load using the following commands:

ServiceProvider sp = services.BuildServiceProvider();
SundryOptions sundryOptions = sp.GetService<IOptions<SundryOptions>>().Value;

The problem I have is that using Property Initialisers never sets the Terminals List correctly. I do need a list (and not a Dictionary) as the enties could be double ie Technik in my example.

I am assuming that I have some error in the Class -> I would be happy for any pointers.

Answer 1

Implement processing of configuration as following somewhere approporiate like this:

var cookieName = 
Configuration.GetSection("SundrySettings:CookieName").Value;
var accessGroup = Configuration.GetSection("SundrySettings:AccessGroup").Value;

var terminals = new List<Terminal>()

var terminalSections = this.Configuration.GetSection("Terminals").GetChildren();
foreach (var item in terminalSections)
{
    terminals.Add(new Terminal 
    {
           // perform type mapping here 
    });
}

SundryOptions sundryOption = new SundryOptions()
{
        CookieName = cookieName,
        HRAccessGroup = accessGroup,
        Terminals = terminalList
};

Of course there could be shorter version, but you can start from here.

Answer 2

Do as follows:

var cookieName = Configuration.GetSection("SundrySettings:CookieName").Value;
var accessGroup = Configuration.GetSection("SundrySettings:AccessGroup").Value;
var terminals = Configuration.GetSection("SundrySettings:Terminals").GetChildren();

List<Terminal>  terminalList = new List<Terminal>();

foreach (var keyValuePair in terminals)
{
     Terminal termial = new Terminal()
     {
          Name = keyValuePair.Key,
          Description = keyValuePair.Value
     };

     terminalList.Add(termial);
}

SundryOptions sundryOption = new SundryOptions()
{
            CookieName = cookieName,
            HRAccessGroup = accessGroup,
            Terminals = terminalList
};

I have checked with the exact configuration you provided and it works perfectly.

Answer 3

If Terminals is a list, in your appSettings, it should be an array, not an object.

  "Terminals" :  [
  "Raucherplatz" : "tablet1.local",
  "Service" :      "tablet2.local",  
  "Technik" :      "tablet3.local",  
  "Technik" :      "tablet4.local",  
  "Container" :    "tablet5.local"
]