Question

我有三张相关的表格。日历1 ... * CalendarUser * ... 1位用户。当我在编辑日历视图中编辑CalendarUsers时，我将ViewModel发布回控制器。这是我的控制器代码：

    [HttpPost]
    public ActionResult Edit(int id, CreateCalendarViewModel cvm)
    {
        long userId = long.Parse(User.Identity.Name);

        db.Calendars.Attach(cvm.CurrentCalendar);
        cvm.Users= DbExtensions.GetUserList(userId);

        if (ModelState.IsValid)
        {
            ////Remove the deselected users
            cvm.CurrentCalendar.CalendarUsers.Clear();

            //Get the names from the selected users
            var selectedUsers = from u in cvm.Users
                                where cvm.SelectedUsers.Contains(u.Key)
                                select new KeyValuePair<long, string>(long.Parse(u.Key), u.Value);

            foreach (var selectedUser in selectedUsers)
            {

                User user = db.Users.Find(selectedUser.Key);

                //If usr does not exist create a new
                if (user == null)
                {
                    db.Users.Add(new User
                    {
                        UserId = selectedUser.Key,
                        Name = selectedUser.Value,
                        Expires = DateTime.Now,
                        AccessToken = string.Empty
                    });
                }

                //Add the binding to the calendar
                cvm.CurrentCalendar.CalendarUsers.Add(new CalendarUser
                {
                    CalendarId = cvm.CurrentCalendar.CalendarId,
                    UserId = selectedUser.Key
                });
            }

            db.Entry(cvm.CurrentCalendar).State = EntityState.Modified;

            db.SaveChanges();

        }

        return View(cvm);
    }

以下是我的课程：

public partial class Calendar 
{ 
    public Calendar() 
    { 
        this.CalendarUsers = new HashSet<CalendarUser>(); 
    } 

    public int CalendarId { get; set; } 
    public string CalendarTitle { get; set; } 
    public string CalendarDescription { get; set; } 
    public long UserId { get; set; } 

    public virtual User User { get; set; } 
    public virtual ICollection<CalendarUser> CalendarUsers { get; set; } 
} 

public partial class CalendarUser 
{ 
    public int CalendarUserId { get; set; } 
    public int CalendarId { get; set; } 
    public long UserId { get; set; } 
    public Nullable<bool> IsAdmin { get; set; } 

    public virtual Calendar Calendar { get; set; } 
    public virtual User User { get; set; } 
} 

public partial class User 
{ 
   public User() 
   { 
       this.Calendars = new HashSet<Calendar>(); 
       this.CalendarUsers = new HashSet<CalendarUser>(); 
   } 

   public long UserId { get; set; } 
   public string Name { get; set; } 

   public virtual ICollection<Calendar> Calendars { get; set; } 
   public virtual ICollection<CalendarUser> CalendarUsers { get; set; } 
}

出于某种原因，当我保存更改时，日历也会被删除？我搜索了一下，但似乎没有人有同样的问题？我做错了吗？有更好的方法来更新/删除相关实体吗？

Answer 1

似乎我忘了在包含用户ID的视图中包含一个隐藏字段，结果是当我更新日历时，它保存为Id = 0，因此隐藏了指定视图中的对象用户。心理记录：始终在数据库中验证实际发生的情况。

我还需要研究在视图和控制器之间来回发送对象时发生的事情。有时它似乎自己管理，有时我需要自己指定所有字段。

清除孩子会删除父母

1 个答案: