实体框架不更新外键对象

您刚刚放错了外键属性的位置

 [Table("ClinicProfile")]
    public class ClinicProfile
    {
        [Key]
        [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
        public int Id { get; set; }
        //[ForeignKey("ContactData")] here the wrong place
        public int ContactDataId { get; set; }
        [ForeignKey("ContactDataId")] // here the correct place
        public ContactData ContactData { get; set; }
    }
    [Table("ContactData")]
    public class ContactData
    {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
         public int Id { get; set; }
         ...
    }

当您想要设置外键数据时，您可以设置ContactDataId值，也可以从数据库中检索ContactData作为对象，并将其设置在ClinicProfile 中

// according to your data posted later
[HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Modify(ClinicProfile clinicProfile, ContactData contactData, AdressData adressData)
        {
            ViewBag.Id = clinicProfile.Id;
            if (ModelState.IsValid)
            {
                if (clinicProfile.Id != 0)
                {
                    // here you want to tell the SharedContext to attach the contactData to the clinicProfile 
                    // you need to retrieve the lastVersion of contactData from db
                    var currentContactData=SharedContext.Current.ContactData.Single(t=>t.Id=contactData.Id);
                    // update the changed data in the currentContactData
                    clinicProfile.ContactData =currentContactData;  // instead of contactData;
                    clinicProfile.AdressData = adressData;
                    clinicProfile.AdressDataComposed = adressData.ComposeData();
                    clinicProfile.ContactDataComposed = contactData.ComposeData();
                    SharedContext.Current.Entry(clinicProfile).State = EntityState.Modified;
                    SharedContext.Current.SaveChanges();
                    Config.SaveClinicPhoto(clinicProfile.ClinicImageUpload, clinicProfile.Id);
                    Config.SaveClinicPreviewPhoto(clinicProfile.ClinicImageUpload, clinicProfile.Id);
                    return View(new ClinicProfileComposite { AdressData = adressData, ClinicProfile = clinicProfile, ContactData = contactData });
                }
                {
                    clinicProfile.ContactData = contactData;
                    clinicProfile.AdressData = adressData;
                    clinicProfile.AdressDataComposed = adressData.ComposeData();
                    clinicProfile.ContactDataComposed = contactData.ComposeData();
                    SharedContext.Current.Entry(clinicProfile).State = EntityState.Added;
                    SharedContext.Current.SaveChanges();
                    Config.SaveClinicPhoto(clinicProfile.ClinicImageUpload, clinicProfile.Id);
                    Config.SaveClinicPreviewPhoto(clinicProfile.ClinicImageUpload, clinicProfile.Id);
                    return RedirectToAction("Info", new { id = clinicProfile.Id });
                }
            }
            ViewBag.Id = clinicProfile.Id;
            return View(new ClinicProfileComposite { AdressData = adressData, ClinicProfile = clinicProfile, ContactData = contactData });
        }

//作为评论讨论的结果

如果你想更新contactData，你需要通过将其状态设置为"已修改"来告诉上下文contactData已被修改，正如你在上一篇文章中提到的，如果你进行以下操作，它就会起作用：

SharedContext.Current.Entry（clinicProfile）.State=EntityState.Modified；SharedContext.Current.Entry（contactData）.State=EntityState.Modified；SharedContext.Current.SaveChanges（）；

希望这将帮助您

更新时，只需要设置ContactDataId

clinicProfile.ContactData = contactData;
clinicProfile.ContactDataId = contactData.Id;
SharedContext.Current.Entry(clinicProfile).State = EntityState.Modified;
SharedContext.Current.SaveChanges();

如果您将新的ContactData设置为现有的ClinicProfile，则应首先将新的Contact Data保存到数据库，然后获取其新Id，第三次使用新的ContactDataId更新ClinicProfile。

clinicProfile.ContactDataId = newContactData.Id;
SharedContext.Current.Entry(clinicProfile).State = EntityState.Modified;
SharedContext.Current.SaveChanges();

如果你想更新现有的ContactData属性，那么你应该只保存它。

SharedContext.Current.Entry(existingContactData).State = EntityState.Modified;
SharedContext.Current.SaveChanges();