Inject IOptionsMonitor with Autofac - using Options pattern

Question

I have problem with injecting IOptionsMonitor with Autofac.

Everything works properly with IOptions, but i'm not able to make it work properly using IOptionsMonitor.

For IOptions registration looks as below:

var cfg = _configuration.GetSection("GlobalAppSettings").Get<GlobalAppSettings>();
builder.Register(c => Options.Create(cfg)).SingleInstance();

And now in constructor:

public class ConfigurationReader : IConfigurationReader
{
    public GlobalAppSettings GlobalAppSettings { get; }

    public ConfigurationReader(IOptions<GlobalAppSettings> _globalAppSettings)
    {
        GlobalAppSettings = _globalAppSettings.Value;
    }
 }

But how to make it works with IOptionsMonitor? Is this a way to create it like IOptions using "Options.Create()" ?

Answer 1

You need to add the following Nuget packages in to your project:

• Autofac.Extensions.DependencyInjection
• Microsoft.Extensions.Options

Create a new ServiceCollection with the AddOptions() method. Then add the ServiceCollection to your Autofac builder via Populate() method.

var serviceCollection = new Microsoft.Extensions.DependencyInjection.ServiceCollection().AddOptions();
var builder = new Autofac.ContainerBuilder();
builder.Populate(serviceCollection);
var container = builder.Build();

After, you can inject IOptions, IOptionsSnapshot and IOptionsMonitor.