.NET 8 Keyed Services - One Interface Multiple Implementations - Ways to Resolve Implementations

controller.cs

// ---------------------------------------------------------------------------------
// DEMO 1 - Inject using FromKeyedServices attribute
// ---------------------------------------------------------------------------------
[Route("api/[controller]")]
[ApiController]
public class FirstController : ControllerBase
{
    // This should be email service implementation
    private readonly IReminderService reminderService;

    public FirstController([FromKeyedServices("Email")] IReminderService reminderService)
    {
        this.reminderService = reminderService;
    }

    [HttpGet("email")]
    public IActionResult Get()
    {
        this.reminderService.SendReminder();
        return Ok(new { Message = "Success" });
    }
}

// ---------------------------------------------------------------------------------
// DEMO 2 - Resolve using GetRequiredKeyedService API 
// ---------------------------------------------------------------------------------
[Route("api/[controller]")]
[ApiController]
public class SecondController : ControllerBase
{
    // This should be SMS service implementation
    private readonly IReminderService reminderService;

    public SecondController(IServiceProvider serviceProvider)
    {
        this.reminderService = serviceProvider
            .GetRequiredKeyedService<IReminderService>(ReminderType.Sms); ;
    }

    [HttpGet("sms")]
    public IActionResult Get()
    {
        this.reminderService.SendReminder();
        return Ok();
    }
}

// ---------------------------------------------------------------------------------
// DEMO 3 - Inject using FromKeyedServices attribute
// ---------------------------------------------------------------------------------
[Route("api/[controller]")]
[ApiController]
public class ThirdController : ControllerBase
{
    // This should be Push Notification service implementation
    private readonly IReminderService reminderService;

    public ThirdController(
        [FromKeyedServices(ReminderType.PushNotifications)]
        IReminderService reminderService)
    {
        this.reminderService = reminderService;
    }

    [HttpGet("pushNotifications")]
    public IActionResult Get()
    {
        this.reminderService.SendReminder();
        return Ok();
    }
}