ASP.NET MVC 5 - 如何在ViewModel中添加[必需的]數據註釋

Question

我在我的視圖模型中調用了三個模型（Unit，Site，Work_Type），名爲UnitAdminViewModel。我需要從單元模型中根據需要設置一個字段。因爲我使用的是數據庫優先方法，所以我無法直接修改單元模型，因爲它會自動生成。我怎樣才能成功添加：

[Required(ErrorMessage = "Group is required")] public string GroupName { get; set; }

到我的視圖模型UnitAdminViewModel？

public class UnitAdminViewModel 
{ 
    public Unit Unit { get; set; } 
    public List<Site> Site { get; set; } 
    public IEnumerable<Work_Type> Work_Type { get; set; } 
} 

在機組型號，我想設置現場的groupName [必需]

public partial class Unit 
{ 
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")] 
    public Unit() 
    { 
     this.Staffs = new HashSet<Staff>(); 
    } 

    public int UnitID { get; set; } 
    public string UnitCode { get; set; } 
    public string UnitName { get; set; } 
    public string GroupName { get; set; } 
    public byte IncentiveUnit { get; set; } 
    public bool CallCenter { get; set; } 
    public bool CDWUnit { get; set; } 
    public string CDWSite { get; set; } 
    public Nullable<int> SiteID { get; set; } 
    public Nullable<int> DivisionID { get; set; } 
    public bool WFCUnit { get; set; } 
    public bool QAMonitored { get; set; } 
    public bool NICEMonitored { get; set; } 
    public string ListPrefix { get; set; } 
    public string TSHSource { get; set; } 
    public string StatsSource { get; set; } 
    public string DialerSource { get; set; } 
    public Nullable<int> CostCenterID { get; set; } 
    public int WaterfallView { get; set; } 
    public bool Locked { get; set; } 
    public string Platform { get; set; } 
    public Nullable<int> Supplier { get; set; } 
    public string Work_Type { get; set; } 

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")] 
    public virtual ICollection<Staff> Staffs { get; set; } 
} 

---

更新

---

我試圖去關@Izzy例子。我覺得我更接近，但[必填]仍然不會觸發驗證錯誤，當我提交表單沒有填充該字段。 @Izzy，有什麼我可能會失蹤？

視圖模型

public class UnitAdminViewModel 
{ 
    public Unit Unit { get; set; } 
    public List<Site> Site { get; set; } 
    public IEnumerable<Work_Type> Work_Type { get; set; } 

} 

UnitMetaData類

[MetadataType(typeof(UnitMetaData))] 
    public partial class Unit 
    { 

    } 

    public class UnitMetaData { 
     [Required(ErrorMessage = "Group is required")] 
     public string GroupName { get; set; } 

     [Required(ErrorMessage = "UnitName is required")] 
     public string UnitName { get; set; } 

     public string CDWSite { get; set; } 

     public string Platform { get; set; } 

     public Nullable<int> Supplier { get; set; } 

     public string Work_Type { get; set; } 
} 

VIEW

@model WebReportingToolDAL.Models.ViewModels.UnitAdminViewModel 

@{ 
    ViewBag.Title = "Create"; 
    Layout = "~/Views/Shared/_Layout.cshtml"; 
} 

<h2>Create</h2> 

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

<div class="form-horizontal"> 
    <h4>Unit</h4> 
    <hr /> 
    @Html.ValidationSummary(true, "", new { @class = "text-danger" }) 

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

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

    <div class="form-group"> 
     @Html.LabelFor(model => model.Unit.CDWSite, htmlAttributes: new { @class = "control-label col-md-2" }) 
     <div class="col-md-10"> 
      @Html.DropDownListFor(model => model.Unit.CDWSite, new SelectList(Model.Site, "SiteName", "SiteName"), new { @class = "form-control" }) 
     </div> 
    </div> 

    <div class="form-group"> 
     @Html.LabelFor(model => model.Unit.Platform, htmlAttributes: new { @class = "control-label col-md-2" }) 
     <div class="col-md-10"> 
      @Html.DropDownListFor(model => model.Unit.Platform, new List<SelectListItem> { new SelectListItem { Text = "PSCC", Value = "PSCC" }, new SelectListItem { Text = "RC", Value = "RC" } }, new { @class = "form-control" }) 
     </div> 
    </div> 

    <div class="form-group"> 
     @Html.LabelFor(model => model.Unit.Supplier, htmlAttributes: new { @class = "control-label col-md-2" }) 
     <div class="col-md-10"> 
      @Html.DropDownListFor(model => model.Unit.Supplier, new List<SelectListItem> { new SelectListItem { Text = "0", Value = "0" }, new SelectListItem { Text = "1", Value = "1" } }, new { @class = "form-control" }) 
     </div> 
    </div> 

    <div class="form-group"> 
     @Html.LabelFor(model => model.Unit.Work_Type, htmlAttributes: new { @class = "control-label col-md-2" }) 
     <div class="col-md-10"> 
      @Html.DropDownListFor(model => model.Unit.Work_Type,new SelectList(Model.Work_Type, "Name", "Name"),new { @class = "form-control" }) 
     </div> 
    </div> 

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

控制器

​​

Answer 1

當使用數據庫第一種方法，你會意識到類被標記爲partial所以你可以做的是利用MetadataType屬性來實現你以後。

因此，請繼續創建一個文件並將其命名爲例如UnitMetaData。您的代碼應該是這個樣子：

public class UnitMetaData 
{ 
    [Required(ErrorMessage = "Group is required")] 
    public string GroupName { get; set; } 
    //more properties 
} 

你Unit類是局部的，所以你可以創建它的另一個文件，並使用MetadataType爲：

[MetadataType(typeof(UnitMetaData))] 
public partial class Unit 
{ 
} 

更多MetadataTypehere

partial定義：

It is possible to split the definition of a class or a struct, an interface or a method over two or more source files. Each source file contains a section of the type or method definition, and all parts are combined when the application is compiled.

source

請注意：確保namespace是一樣的生成Unit類，否則將無法正常工作

Answer 2

您可以使用真正的視圖模型，換一個。簡單地將一堆實體包裝在一個類中就是缺少什麼視圖模型的重點。您的視圖模型應該只包含應該顯示/編輯的屬性，並且應該包含視圖的業務邏輯，例如GroupName是必需的（當它顯然不在數據庫級別時）。

這意味着創建類似：

public class UnitViewModel 
{ 
    // other properties you want to edit 

    [Required] 
    public string GroupName { get; set; } 
} 

然後，您在您的視圖中使用這個而不是Unit，並從UnitViewModel張貼的屬性映射到您的Unit實例。