.net core 3.0 创建种子环类时出现关于托管的错误

如何解决.net core 3.0 创建种子环类时出现关于托管的错误

出现异常处理错误。

System.ArgumentException: 'Keyword not supported: '"server'.'

ButchTreat.Data.DutchSeeder.seed() in DutchSeeder.cs
ButchTreat.Program.Runseeding(Microsoft.AspNetCore.Hosting.IWebHost) in 
Program.cs
ButchTreat.Program.Main(string[]) in Program.cs

代码如下：

   public class DutchSeeder
{ 
private readonly DutchContext _ctx;
private readonly IHostEnvironment _hosting;
public  DutchSeeder(DutchContext ctx,IHostEnvironment hosting){
_ctx = ctx;
}

    public Product Product { get; private set; }
    public int Quantity { get; private set; }
    public decimal UnitPrice { get; private set; }

    public void seed()
{
   

        if (!_ctx.Products.Any())
        {
            _ctx.Database.EnsureCreated();
            var filepath = Path.Combine(_hosting.ContentRootPath,"Date/art.json");
            var json = System.IO.File.ReadAllText(filepath);
            var products = JsonConvert.DeserializeObject<IEnumerable<Product>>(json);
            _ctx.Products.AddRange(products);
            var orders = _ctx.Orders.Where(o => o.Id == 1).FirstOrDefault();
            if (orders != null)
            {

                orders.Items = new List<OrderItem>()
                {

                    new OrderItem()
                    {
                        Product = products.First(),Quantity = 5,UnitPrice = products.First().Price
                    }
                       // Product = Product.First();
                       

                };
            }
            _ctx.SaveChanges();
    }
}