如何从MVC3中的编辑页面更新视图模型？

Question

我有三个模型聚集在一起创建一个视图模型,我希望能够在单击"编辑"时编辑该视图模型.我无法找到一个直接的例子,说明这是如何工作的(任何地方).

我不确定自己是否走正路.我能够获得数据视图.此时,我无法保存.

任何帮助,将不胜感激.

谢谢!

楷模:

    public class Person
{
    [Key]
    public int Id { get; set; }

    [MaxLength(20)]
    [Required(ErrorMessage = "First name is required.")]
    public string FirstName { get; set; }

    [MaxLength(20)]
    [Required(ErrorMessage = "Last name is required.")]
    public string LastName { get; set; }
    [MaxLength(40)]
    [Required(ErrorMessage = "Email is required.")]
    public string Email { get; set; }
    [MaxLength(20)]
    [DataType(DataType.PhoneNumber)]
    public string Phone { get; set; }

    public bool Active { get; set; }
}


    public class ClientContact
{
    [Key]
    [ForeignKey("Person")]
    public int ClientPersonId { get; set; }
    public int ClientId { get; set; }
    [MaxLength(40)]
    public string Title { get; set; }

    public Person Person { get; set; }
    [ForeignKey("ClientId")]
    public Client Client { get; set; }
}

    public class Client
{
    [Key]
    public int ClientId { get; set; }
    public string Name { get; set; }
    public bool Active {get;set;}

}

查看型号:

    public class ClientContactViewModel
{

    private SimplexDB db = new SimplexDB();


    public ClientContactViewModel()
    { 

    }


    public ClientContactViewModel(int id)
    {
        ClientPersonId = id;
        InitializeClientContact();
    }

    public int ClientPersonId { get; set; }


    [Display(Name = "First Name")]
    public string FirstName { get; set; }
    [Display(Name = " Last Name")]
    public string LastName { get; set; }
    [Display(Name = "Title")]
    public string Title { get; set; }
    [Display(Name = "Email Address")]
    public string Email { get; set; }
    [Display(Name = "Phone")]
    public string Phone { get; set; }
    [Display(Name = "Client Name")]
    public int ClientId { get; set; }


    public SelectList Clients
    {
        get
        {
            return new SelectList(db.Clients, "ClientId", "Name");

        }
    }

    private void InitializeClientContact()
    {
        var contact = db.ClientPersons.Include("Person").Where(x => x.ClientPersonId == ClientPersonId).SingleOrDefault();
        if (contact != null)
        {
            FirstName = contact.Person.FirstName;
            LastName = contact.Person.LastName;
            Title = contact.Title;
            Email = contact.Person.Email;
            Phone = contact.Person.Phone;
            ClientId = contact.ClientId;

        }
    }



}

控制器:

                public class ClientContactController : Controller
    {
        private database db = new database();

//
        // GET: /ClientContact/Edit/5

        public ActionResult Edit(int id)
        {
            return View(new ClientContactViewModel(id));
        }

        //
        // POST: /ClientContact/Edit/5

        [HttpPost]
        public ActionResult Edit(ClientContactViewModel model)
        {
            if (ModelState.IsValid)
            {
                db.Entry(model).State = EntityState.Modified;
                db.SaveChanges();
                return RedirectToAction("Index");
            }
            return View(model);
        }
}

我在db.Entry(model).State ...得到一个错误"实体类型ClientContactViewModel不是当前上下文模型的一部分."

Answer 1

您的ViewModel不是实体.您应该将ViewModel映射到您的实体,然后将实体的状态设置为modified.

基本上,这意味着您应该使用视图模型值设置实体值.您可以使用AutoMapper或手动处理它:

    [HttpPost]
    public ActionResult Edit(ClientContactViewModel model)
    {
        if (ModelState.IsValid)
        {
            ClientContact contact = db.ClientPersons.Include("Person")
                                    .Where(x => x.ClientPersonId == model.ClientPersonId)
                                    .SingleOrDefault();
            contact.FirstName = model.FirstName;
            // etc
            db.Entry(contact).State = EntityState.Modified;
            db.SaveChanges();
            return RedirectToAction("Index");
        }
        return View(model);
    }

有关在MVC中使用ViewModel的出色方法,请参见http://lostechies.com/jimmybogard/2009/06/30/how-we-do-mvc-view-models/.

此外,我强烈建议您不要在ViewModel中进行任何数据访问.在Controller中,或者甚至更好地在Controller使用的存储库中执行此操作.模型绑定不适用于具有逻辑的模型(即它们不应包含除简单get/set属性之外的任何内容).