c# - How to access appsettings from another project

Question

In the startup file I need a way to access IConfiguration in another project. I have been told the Business Logic should not know about IConfiguration. If thats the case then how do I inject data from appsettings down to the business logic projects.

appsettings.json

{
  "AdminEmail": "myemail@gmail.com"
}

How would I access AdminEmail in a class library I created in the same solution?

Answer 1

• Define a model for settings

  public sealed class EmailSettings
  {
      public string AdminEmail { get; set; }
  }
  

• Configure settings

  public sealed class Startup
  {
      private readonly IConfiguration configuration;
  
      public Startup(IConfiguration configuration) => this.configuration = configuration;
  
      public void ConfigureServices(IServiceCollection services)
      {
          services
              .Configure<EmailSettings>(configuration)
              .AddSingleton(sp => sp.GetRequiredService<IOptions<EmailSettings>>().Value);
      }
  }
  

• Inject and use it

  public class ClassLibraryInTheSameSolution
  {
      public ClassLibraryInTheSameSolution(EmailSettings emailSettings)
      {                         
      }
  }