'BackgroundService' is a namespace but is used like a type

Question

I'm creating a background service in .NET 8, but I get the below error

Error CS0118 'BackgroundService' is a namespace but is used like a type

This was working in .NET 6 version.

I have uninstalled and reinstalled Microsoft.Extensions.Hosting but does not seem to work.

Creating new project and facing this issue:

using Microsoft.Extensions.Hosting;

namespace BackgroundService
{
    public class Worker : BackgroundService
    {
        private readonly ILogger<Worker> _logger;

        public Worker(ILogger<Worker> logger)
        {
            _logger = logger;
        }

        protected override async Task ExecuteAsync(CancellationToken stoppingToken)
        {
            while (!stoppingToken.IsCancellationRequested)
            {
                if (_logger.IsEnabled(LogLevel.Information))
                {
                    _logger.LogInformation("Worker running at: {time}", DateTimeOffset.Now);
                }
                await Task.Delay(1000, stoppingToken);
            }
        }
    }
}

Answer 1

Change the namespace BackgroundService to something else otherwise it shadows the type name:

namespace MyApp.BackgroundServices
{
    public class Worker : BackgroundService
    {
        // ...
    }
}

Alternatively you can specify the fully qualified type name (though I would argue that the first option should be preferred):

public class Worker : Microsoft.Extensions.Hosting.BackgroundService
{
   // ...
}