marechai/cicm_web/Areas/Admin/Models/CompanyViewModel.cs

using System;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using Cicm.Database;

namespace cicm_web.Areas.Admin.Models
{
    public class CompanyViewModel
    {
        public int    Id   { get; set; }
        public string Name { get; set; }
        [DisplayFormat(DataFormatString = "{0:d}", ApplyFormatInEditMode = true)]
        [DataType(DataType.Date)]
        public DateTime? Founded { get; set; }
        [DisplayFormat(DataFormatString = "{0:d}")]
        [DataType(DataType.Date)]
        public DateTime? Sold { get; set; }
        public string SoldTo  { get; set; }
        public string Country { get; set; }
        [Required]
        public CompanyStatus Status { get; set; }

        [DisplayName("Sold")]
        [NotMapped]
        public string SoldView =>
            Status != CompanyStatus.Active && Status != CompanyStatus.Unknown
                ? Sold is null
                      ? "Unknown"
                      : Sold.Value.ToShortDateString()
                : Sold is null
                    ? SoldTo is null
                          ? ""
                          : "Unknown"
                    : Sold.Value.ToShortDateString();
    }
}