我正在為我的項目使用Identity框架，JobExperience并向User類添加了一些屬性。用戶應(yīng)該有加入的可能性，JobExperience他們的User。自然地，這意味著aJobExperience不能不存在而存在User。因此，我在JobExperience課堂上使用[Required]表示法JobExperience類public class JobExperience{    public int JobExperienceId { get; set; }    public string Employer { get; set; }    public DateTime? DateOfEmployment { get; set; }    public DateTime? DateOfExit { get; set; }    public ICollection<Subject> Subjects { get; set; }    [Required]    public virtual User ApplicationUser { get; set; }}用戶類別public class User : IdentityUser{    public Boolean Available { get; set; }    public Boolean ActivelySeeking { get; set; }    public Boolean AcceptedUseOfData { get; set; }    public int ExpectedHourlySalary { get; set;}    public Boolean Gender { get; set;}    public DateTime? DateOfBirth { get; set; }    public String FirstName { get; set; }    public string LastName { get; set; }    public ICollection<JobExperience> JobExperiences { get; set; }    public ICollection<Language> Languages { get; set; }    public ICollection<Certificate> Certificates { get; set; }}腳手架JobExperienceController-創(chuàng)建方法[HttpPost][ValidateAntiForgeryToken]public ActionResult Create([Bind(Include = "JobExperienceId,Employer,DateOfEmployment,DateOfExit")] JobExperience jobExperience){    var UserId = User.Identity.GetUserId();    jobExperience.ApplicationUser = db.Users.Where(x => x.Id == UserId).First();    if (ModelState.IsValid)    {       db.JobExperiences.Add(jobExperience);       db.SaveChanges();       return RedirectToAction("Index");    }    return View(jobExperience);}添加了Required-notation后，create方法中的modelstate.isValid（）返回false。我猜想它需要收到用戶的參考，但我不知道如何去做。當(dāng)前嘗試是所示的LINQ表達(dá)式。ApplicationUserDb public class ApplicationUserDb : IdentityDbContext<User>{    public virtual DbSet<JobExperience> JobExperiences { get; set; }    public virtual DbSet<Language> Languages { get; set; }    public virtual DbSet<Certificate> Certificates { get; set; }    public ApplicationUserDb() : base("DefaultConnection")    {    }