模型视图模型失效viewmodel控制器

Question

我是ASP.NET MVC 5的新手。我试图制作一个用户管理软件。但在用户注册（创建）控制器中，我的模型已失效。不知道为什么。我可能在我的模型绑定中发生错误。这是附加的代码。任何帮助表示赞赏。

型号文件

public class UserData 
{ 

    [Key] 
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)] 
    public int userid { get; set; } 


    [Required(ErrorMessage = "Domain ID")] 
    [Display(Name = "Domain ID")] 
    public string domainid { get; set; } 

    [Required(ErrorMessage = "Choose Role")] 
    [Display(Name = "Role")] 
    public string role { get; set; } 

    [Required(ErrorMessage = "Choose Country")] 
    [Display(Name = "Country")] 
    public string country { get; set; } 

    [Required(ErrorMessage = "Choose BU")] 
    [Display(Name = "BU")] 
    public string bu { get; set; } 

    [Required] 
    [RegularExpression(@"^(([\w-]+\.)+[\w-]+|([a-zA-Z]{1}|[\w-]{2,}))@" 
+ @"((([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\.([0-1]? 
      [0-9]{1,2}|25[0-5]|2[0-4][0-9])\." 
+ @"([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\.([0-1]? 
      [0-9]{1,2}|25[0-5]|2[0-4][0-9])){1}|" 
+ @"([a-zA-Z]+[\w-]+\.)+[a-zA-Z]{2,4})$", ErrorMessage = "Please Provide Valid Email-ID")] 
    [Display(Name = "Email"),DataType(DataType.EmailAddress)] 
    public string email { get; set; } 


    [HiddenInput(DisplayValue=true)] 
    public DateTime date_from { get; set; } 

    [HiddenInput(DisplayValue = true)] 
    public DateTime date_to { get; set; } 

    [HiddenInput(DisplayValue=true)] 
    public bool active { get; set; } 

     } 

视图模型文件

public class UserRegistrationViewModel 

{ 

    public UserData userdata { get; set; } 

    public string SelectedRole { get; set; } 
    public IEnumerable<SelectListItem> RoleList { get; set; } 


    public string SelectedCountry { get; set; } 
    public IEnumerable<SelectListItem> CountryList { get; set; } 


    public string SelectedBU { get; set; } 
    public IEnumerable<SelectListItem> BUList { get; set; } 

} 

控制器的文件

public class UserDatasController : Controller 
{ 
    private ApplicationDataContext db = new ApplicationDataContext(); 

    // GET: UserDatas 
    public ActionResult Index() 
    { 
     return View(db.UsersData.ToList()); 
    } 
     public ActionResult Create() 
    { 
     var model = new UserRegistrationViewModel(); 
     model.CountryList = from p in XDocument.Load("C:/Users/inkosah/Documents/Visual Studio 2013/Projects/Policy Assessment/Policy Assessment/country_list.xml").Descendants("Name") 
          //var a=Path.GetFullPath("Policy Asse") 
          let value = (string)p.Element("Text") 
          select new SelectListItem 
          { 
           Selected = (value == model.SelectedCountry), 
           Text = (string)p.Element("Text"), 
           Value = value 
          }; 
     model.BUList = from q in XDocument.Load("C:/Users/inkosah/Documents/Visual Studio 2013/Projects/Policy Assessment/Policy Assessment/bu_list.xml").Descendants("BU") 
         let value2 = (string)q.Element("BU_Name") 
         select new SelectListItem 
         { 
          Selected = (value2 == model.SelectedBU), 
          Text = (string)q.Element("BU_Name"), 
          Value = value2 
         }; 


     model.RoleList = from n in XDocument.Load("C:/Users/inkosah/Documents/Visual Studio 2013/Projects/Policy Assessment/Policy Assessment/UserRoleList.xml").Descendants("Role") 
         let value1 = (string)n.Element("Role_Name") 
         select new SelectListItem 
         { 
          Selected = (value1 == model.SelectedRole), 
          Text = (string)n.Element("Role_Name"), 
          Value = value1 
         }; 
     return View(model); 
    } 

    // POST: UserDatas/Create 
    // To protect from overposting attacks, please enable the specific properties you want to bind to, for 
    // more details see http://go.microsoft.com/fwlink/?LinkId=317598. 
    [HttpPost] 
    [ValidateAntiForgeryToken] 
    public ActionResult Create([Bind(Include = "SelectedRole,SelectedCountry,SelectedBU")]UserRegistrationViewModel RegisterData,[Bind(Include="domainid,email")] UserData userdata) 
    { 
     userdata.date_from = DateTime.Now; 
     userdata.date_to = DateTime.MaxValue; 
     userdata.active = false; 
     userdata.role = RegisterData.SelectedRole; 
     userdata.bu = RegisterData.SelectedBU; 
     userdata.country = RegisterData.SelectedCountry; 

     if (ModelState.IsValid) 
     { 

      db.UsersData.Add(userdata); 
      db.SaveChanges(); 
      return RedirectToAction("Index"); 
     } 

     return View(userdata); 
    } 

create.cshtml

@model Policy_Assessment.ViewModels.UserRegistrationViewModel 

@{ 
    ViewBag.Title = "User Registration Page"; 
} 


@using (Html.BeginForm()) 
{ 
    @Html.AntiForgeryToken() 

    <div class="form-horizontal"> 
     <h4>User Input</h4> 
     <hr /> 
     @Html.ValidationSummary(true) 
     <div class="form-group"> 
      @Html.LabelFor(model => model.userdata.domainid, htmlAttributes: new { @class = "control-label col-md-2" }) 
      <div class="col-md-10"> 
       @Html.EditorFor(model => model.userdata.domainid) 
       @Html.ValidationMessageFor(model => model.userdata.domainid) 
      </div> 
     </div> 

     <div class="form-group"> 
      @Html.LabelFor(model => model.userdata.role, htmlAttributes: new { @class = "control-label col-md-2" }) 
      <div class="col-md-10"> 
       @*@Html.EditorFor(model => model.role)*@ 
       @Html.DropDownListFor(model => model.SelectedRole, Model.RoleList, "-----Role-----") 
       @Html.ValidationMessageFor(model=>model.SelectedRole) 
      </div> 
     </div> 

     <div class="form-group"> 
      @Html.LabelFor(model => model.userdata.country, htmlAttributes: new { @class = "control-label col-md-2" }) 
      <div class="col-md-10"> 
       @*@Html.EditorFor(model => model.country)*@ 
       @Html.DropDownListFor(model => model.SelectedCountry,Model.CountryList,"----Country-----") 
       @Html.ValidationMessageFor(model => model.userdata.country) 
      </div> 
     </div> 

     <div class="form-group"> 
      @Html.LabelFor(model => model.userdata.bu, htmlAttributes: new { @class = "control-label col-md-2" }) 
      <div class="col-md-10"> 
       @Html.DropDownListFor(model=>model.SelectedBU,Model.BUList,"--Select BU----") 
       @Html.ValidationMessageFor(model => model.userdata.bu) 
      </div> 
     </div> 

     <div class="form-group"> 
      @Html.LabelFor(model => model.userdata.email, htmlAttributes: new { @class = "control-label col-md-2" }) 
      <div class="col-md-10"> 
       @Html.EditorFor(model => model.userdata.email) 
       @Html.ValidationMessageFor(model => model.userdata.email) 
      </div> 
     </div> 

     @*<div class="form-group"> 
      @Html.HiddenFor(model => model.userdata.date_from, htmlAttributes: new { @class = "control-label col-md-2" }) 
      <div class="col-md-10"> 
       @Html.HiddenFor(model => model.userdata.date_from) 
       @Html.ValidationMessageFor(model => model.userdata.date_from) 
      </div> 
     </div> 

     <div class="form-group"> 
      @Html.HiddenFor(model => model.userdata.date_to, htmlAttributes: new { @class = "control-label col-md-2" }) 
      <div class="col-md-10"> 
       @Html.HiddenFor(model => model.userdata.date_to) 
       @Html.ValidationMessageFor(model => model.userdata.date_to) 
      </div> 
     </div> 

     <div class="form-group"> 
      @Html.HiddenFor(model => model.userdata.active, htmlAttributes: new { @class = "control-label col-md-2" }) 
      <div class="col-md-10"> 
       @Html.HiddenFor(model => model.userdata.active) 
       @Html.ValidationMessageFor(model => model.userdata.active) 
      </div> 
     </div>*@ 

     <div class="form-group"> 
      <div class="col-md-offset-2 col-md-10"> 
       <input type="submit" value="Register" class="btn btn-default" /> 
      </div> 
     </div> 
    </div> 
} 

@*<div> 
    @Html.ActionLink("Back to List", "Index") 
</div>*@ 

<script src="~/Scripts/jquery-1.10.2.min.js"></script> 
<script src="~/Scripts/jquery.validate.min.js"></script> 
<script src="~/Scripts/jquery.validate.unobtrusive.min.js"></script> 

上下文文件

public class ApplicationDataContext : DbContext 
{ 
    public ApplicationDataContext() 
     : base("DefaultConnection") 
    { } 

    public System.Data.Entity.DbSet<Policy_Assessment.ViewModels.UserRegistrationViewModel> UserRegistrationData { get; set; } 

    public System.Data.Entity.DbSet<Policy_Assessment.Models.UserData> UsersData { get; set; } 


} 

请注意我在MVC ASP.Net初学者。任何帮助或解释都会有帮助。

Answer 1

你的调令回你的数据模型（包括作为您的视图模型的属性）。数据模型的[Required]属性为role，但您正在为此属性创建控件，因此没有任何约束，这意味着它的null因此无效。两种方法来解决这个问题。

A.从视图模型中取出财产string SelectedRole，并直接绑定到中包含的内容视图模型现在

@Html.DropDownListFor(m => m.userdata.role, Model.RoleList, ...) 

的数据模型，userdata.role将包含选择的选项值，将是有效的（注意，您将需要为其他2个属性做这个）。

B.从视图模型中取出财产​​3210和视图模型包括来自UserData属性正在编辑

public class UserRegistrationViewModel 
{ 
    [Required(ErrorMessage = "Domain ID")] 
    [Display(Name = "Domain ID")] 
    public string domainid { get; set; } 
    [Required(ErrorMessage = "Choose Role")] 
    [Display(Name = "Role")] 
    public string role { get; set; } 
    [Required(ErrorMessage = "Choose Country")] 
    [Display(Name = "Country")] 
    public string country { get; set; } 
    [Required(ErrorMessage = "Choose BU")] 
    [Display(Name = "BU")] 
    public string bu { get; set; } 
    [Required] 
    [Display(Name = "Email"),DataType(DataType.EmailAddress)] 
    [EmailAddress] 
    public string email { get; set; } 
    public SelectList RoleList { get; set; } 
    public SelectList CountryList { get; set; } 
    public SelectList BUList { get; set; } 
} 

注意我已经排除属性，你似乎没有被编辑，使用[EmailAddress]，而不是你的正则表达式（看不出什么的正则表达式就是这么做的EmailAddress属性尚未执行），并使用SelectList而不是IEnumerable<SelectListItem>这意味着你可以把它简化为

public ActionResult Create() 
{ 
    var model = new UserRegistrationViewModel(); 
    var roles = from n in XDocument.Load(.... 
    model.RoleList = new SelectList(roles, "value", "value"); 
    .... 
    return View(model); 
} 

然后在POST方法中，将视图模型中的属性映射到数据模型的新实例，并根据需要设置其他属性，如date_from（或者可以将这些默认值放入构造函数中）并保存到数据库。