ViewCoponent Not Working ...Spinning Errors on Class

I have adapted a couple of examples and think this is more or less correct, but I am getting errors in odd places.  Clearly I have stuffed something up.

The view component:

using Eva804.Data;
using Microsoft.AspNetCore.Mvc;
using System.Linq;
using Microsoft.EntityFrameworkCore;
using System.Threading.Tasks;
using Eva804.Models;

namespace Eva804.ViewComponents
{
    public class Last6ClosedJobsViewComponent :  ViewComponent
    {
        private readonly Eva804Context ctx;

        public Last6ClosedJobsViewComponent(Eva804Context context)
        {
            ctx = context;
        }

        public async Task<IViewComponentResult> InvokeAsync(int id)
        {
            var jobs = from j in ctx.Job
                       .Include(j => j.Site)
                       .Include(j => j.WaterBody)
                       .Where(j => j.Site.SiteID == id && j.InvoiceDate!=null)
                       .OrderByDescending(j => j.BookingDate)
                       .Take(6)
                       select j;

            return View(jobs);
        }

    }
}

I am getting loverly red squiggles on:

 public class Last6ClosedJobsViewComponent :  ViewComponent

ViewComponent is not being accepted producing a namespace but is used like a variable

And on:

return View(jobs);

Where View is saying a namespace but is used like a type.

Clearly I am making some error, but I cannot see it.  Where should I look?  Am I missing a directive or something?