IOptions with Connection string

Question

I have very simple appsettings:

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "ConnectionStrings": {
    "DefaultConnection": "Server=test;Database=test;Trusted_Connection=True;"
  },
  "AllowedHosts": "*"
}

Class for connection string:

public class ConnectionStrings
    {
      public string DefaultConnection { get; set; }
    }

I register in DI it like this:

builder.Services.AddOptions<ConnectionStrings>(builder.Configuration.GetConnectionString("DefaultConnection"));

I inject IOption in constructor, but it is always null:

public class ShoppingCartRepository : IShoppingCartRepository
  {
    private readonly IOptions<ConnectionStrings> _connectionStrings;

    public ShoppingCartRepository(IOptions<ConnectionStrings> connectionStrings)
    {
      _connectionStrings = connectionStrings;
    }

    // ...
 
    }
  }

Can I use IOptions for connection string or I should use another approach?

What is best way of working with connection string?

Answer 1

The AddOptions method accept an argument of type string that is the name of the options instance. But You pass the value of DefaultConnection in appsettings.json to it.

You should add Bind method after AddOptions

builder.Services
    .AddOptions<ConnectionStrings>()
    .Bind(Configuration.GetSection("ConnectionStrings:DefaultConnection"));