问从数据库(由MVC通过虚拟ICollection创建)获取对象的父id

EN

// Board model, containing a title and a collection of threads
public class Board
{
    public int Id { get; set; }
    public string Title { get; set; }
    public virtual ICollection<Thread> Threads { get; set; }
}

// Thread model, containing a title and a collection of posts
public class Thread
{
    public int Id { get; set; }
    public string Title { get; set; }
    public virtual ICollection<Post> Posts { get; set; }
}

// GET: Threads/View/5
[AllowAnonymous]
public ActionResult View(int? id) {
    Thread thread = db.Threads.Find(id);

    // Fetch the parent board Id
    int boardId = ...;

    return View(thread);
}