c# - ModelState.isValid()== False +必填符号

我正在为项目使用Identity框架，并已向JobExperience类添加了一些属性，例如User。

用户应该可以在其JobExperience中添加User。自然地，这意味着JobExperience在没有User的情况下不应该存在。

因此，我在JobExperience类中使用[Required]表示法

JobExperience类

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; }
}

用户类别

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; }
}

脚手架JobExperienceController-创建方法

[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户的参考，但是我不知道如何去做。当前尝试是所示的LINQ表达式。

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")
    {

    }

    internal static ApplicationUserDb Create()
    {
        return new ApplicationUserDb();
    }

}

最佳答案

您想将User JobExperience之间的关系建模为1（必需） 0-N（可选列表）。您无法通过将ApplicationUser标记为[Required]来实现。而是在ModelBuilder中配置多重性约束并删除[Required]属性。

ModelBuilder.Entity<User>()
   .HasMany(u => u.JobExperiences)
   .WithRequired(j => j.ApplicationUser)
   .WillCascadeOnDelete(true);

教程：Configure One-to-Many Relationships in EF 6。

进一步说明，您应该引入ViewModels而不是将实体模型绑定到控制器。这样，您就不会混合用于前端验证的注释（例如[Required]）和用于数据持久性的注释（例如[ForeignKey]）。

如果User从IdentityUser继承，还请确保在您的ModelBuilder中调用base.OnModelCreating(modelBuilder)（请参见EntityType 'IdentityUserLogin' has no key defined. Define the key for this EntityType）。