單視圖中的多個模型（C＃MVC3）

Question

我正在使用C＃和MVC3。

我有一個頁面，例如學生列表，顯示學生列表，這是由數據庫驅動的。 同時我的菜單是數據庫驅動的，所以我也必須將它發送到視圖。

如何將兩個模型發送到單個視圖？

Answer 1

您應始終為視圖創建單獨的ViewModel。 您的視圖應該從您的域模型中抽象出來。 在演示/教程中，他們通過簡單地強烈鍵入視圖到域模型來顯示它非常簡單，但這不是一個好策略。 視圖不應該依賴於業務對象。

即使需要將域模型映射到另一個視圖模型類，您也應該為當前場景以及所有其他視圖實現David Glenn提出的解決方案。

編輯：

如果你已經可以說頂部菜單> TopMenu.aspx而你在它里面>多個部分觀點StudentMenu.ascx ， ResultMenu.ascx

您將創建頂級菜單>視圖模型TopMenuViewModel.cs ，你也將創建局部視圖>視圖模型StudentMenuViewModel ， ResultMenuViewModel等。

並且您的TopMenuViewModel將具有兩個>

class TopMenuViewModel 
{
   //all the stuff required in TopMenu.aspx
   StudentMenuViewModel studentvm;
   ResultMenuViewModel resultvm;
}

在TopMenu.aspx渲染局部時，您將傳遞相關的視圖模型>

Html.RenderPartial('StudentView', Model.studentvm)

希望它有意義

Answer 2

您可以創建一個ViewModel，它代表您的視圖，而不是您的業務模型

public class StudentPage {

  public IEnumerable<Student> Students { get; set; }

  public Menu Menu { get; set; }

}

然后，您的控制器將ViewModel返回到您的視圖

public ViewResult Students() {

   var menu = GetMenu();
   var students = Repository.Students();

   var model = new StudentPage {
     Menu = menu,
     Students = students
   }

   return View(model);

}

我假設菜單是你網頁上的一個重復出現的功能，所以你可能想要分解它

public class BasePage {

  public Menu Menu { get; set; }

}

public class StudentPage : BasePage {

  public IEnumerable<Student> Students { get; set; }

}

您還可以創建一個具有GetMenu()功能的基本控制器，以便在多個控制器之間重用。

Answer 3

注意 ：下面的類應該在.net 3.5及更低版本中使用，因為.net 4作為類似的類引入，稱為Tuple ，應該使用它。

MultiObject<O1, O2, ..>和MultiList<L1, L2, ...>

這是我編寫這樣的控制器動作和視圖的方式：

public ActionResult MultiModel()
{
    MultiList<User, Company> result = MultiList.New(
        this.repository.GetUsers(),
        this.repository.GetCompanies()
    );
    return View(result);
}

我的觀點是：

ViewPage<MultiList<User, Company>>

我正在使用這個可重用的便利類：

#region MultiObject static helper class

/// <summary>
/// Provides static methods for creating multi objects with type inference.
/// </summary>
[SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Multi")]
public static class MultiObject
{
    /// <summary>
    /// Creates a new <see cref="MultiObject{T1, T2}"/> object instance.
    /// </summary>
    /// <typeparam name="T1">The type of the first object.</typeparam>
    /// <typeparam name="T2">The type of the second object.</typeparam>
    /// <param name="first"><typeparamref name="T1"/> object instance.</param>
    /// <param name="second"><typeparamref name="T2"/> object instance.</param>
    /// <returns>
    /// Returns a <see cref="MultiObject{T1, T2}"/> of <typeparamref name="T1"/> and <typeparamref name="T2"/> object instances.
    /// </returns>
    public static MultiObject<T1, T2> New<T1, T2>(T1 first, T2 second)
    {
        return new MultiObject<T1, T2>(first, second);
    }

    /// <summary>
    /// Creates a new <see cref="MultiObject{T1, T2, T3}"/> object instance.
    /// </summary>
    /// <typeparam name="T1">The type of the first object.</typeparam>
    /// <typeparam name="T2">The type of the second object.</typeparam>
    /// <typeparam name="T3">The type of the third object.</typeparam>
    /// <param name="first"><typeparamref name="T1"/> object instance.</param>
    /// <param name="second"><typeparamref name="T2"/> object instance.</param>
    /// <param name="third"><typeparamref name="T3"/> object instance.</param>
    /// <returns>
    /// Returns a <see cref="MultiObject{T1, T2, T3}"/> of <typeparamref name="T1"/>, <typeparamref name="T2"/> and <typeparamref name="T3"/> objects instances.
    /// </returns>
    public static MultiObject<T1, T2, T3> New<T1, T2, T3>(T1 first, T2 second, T3 third)
    {
        return new MultiObject<T1, T2, T3>(first, second, third);
    }
}

#endregion

#region MultiObject<T1, T2>

/// <summary>
/// Represents a 2-multi object, or pair.
/// </summary>
/// <typeparam name="T1">The type of the multi object's first component.</typeparam>
/// <typeparam name="T2">The type of the multi object's second component.</typeparam>
[SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Multi")]
public class MultiObject<T1, T2>
{
    /// <summary>
    /// Gets or sets the value of the first multi object component.
    /// </summary>
    /// <value>The first.</value>
    public T1 First { get; set; }

    /// <summary>
    /// Gets or sets the value of the second multi object component.
    /// </summary>
    /// <value>The second multi object component value.</value>
    public T2 Second { get; set; }

    /// <summary>
    /// Initializes a new instance of the <see cref="MultiObject{T1, T2}"/> class.
    /// </summary>
    /// <param name="first">Multi object's first component value.</param>
    /// <param name="second">Multi object's second component value.</param>
    public MultiObject(T1 first, T2 second)
    {
        this.First = first;
        this.Second = second;
    }
}

#endregion

#region MultiObject<T1, T2, T3>

/// <summary>
/// Creates a new 3-multi object, or triple.
/// </summary>
/// <typeparam name="T1">The value of the first component of the multi object.</typeparam>
/// <typeparam name="T2">The value of the second component of the multi object.</typeparam>
/// <typeparam name="T3">The value of the third component of the multi object.</typeparam>
[SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Multi")]
[SuppressMessage("Microsoft.Design", "CA1005:AvoidExcessiveParametersOnGenericTypes")]
public class MultiObject<T1, T2, T3> : MultiObject<T1, T2>
{
    /// <summary>
    /// Gets or sets the value of the third multi object component.
    /// </summary>
    /// <value>The third multi object component value.</value>
    public T3 Third { get; set; }

    /// <summary>
    /// Initializes a new instance of the <see cref="MultiObject{T1, T2, T3}"/> class.
    /// </summary>
    /// <param name="first">Multi object's first component value.</param>
    /// <param name="second">Multi object's second component value.</param>
    /// <param name="third">Multi object's third component value.</param>
    public MultiObject(T1 first, T2 second, T3 third)
        : base(first, second)
    {
        this.Third = third;
    }
}

#endregion

任何當我必須傳遞多個列表時

#region MultiObject static helper class

/// <summary>
/// Provides static methods for creating multi objects with type inference.
/// </summary>
[SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Multi")]
public static class MultiList
{
    /// <summary>
    /// Creates a new <see cref="MultiObject{T1, T2}"/> object instance.
    /// </summary>
    /// <typeparam name="T1">The type of the first object.</typeparam>
    /// <typeparam name="T2">The type of the second object.</typeparam>
    /// <param name="first"><typeparamref name="T1"/> object instance.</param>
    /// <param name="second"><typeparamref name="T2"/> object instance.</param>
    /// <returns>
    /// Returns a <see cref="MultiObject{T1, T2}"/> of <typeparamref name="T1"/> and <typeparamref name="T2"/> object instances.
    /// </returns>
    public static MultiList<T1, T2> New<T1, T2>(IList<T1> first, IList<T2> second)
    {
        return new MultiList<T1, T2>(first, second);
    }

    /// <summary>
    /// Creates a new <see cref="MultiObject{T1, T2, T3}"/> object instance.
    /// </summary>
    /// <typeparam name="T1">The type of the first object.</typeparam>
    /// <typeparam name="T2">The type of the second object.</typeparam>
    /// <typeparam name="T3">The type of the third object.</typeparam>
    /// <param name="first"><typeparamref name="T1"/> object instance.</param>
    /// <param name="second"><typeparamref name="T2"/> object instance.</param>
    /// <param name="third"><typeparamref name="T3"/> object instance.</param>
    /// <returns>
    /// Returns a <see cref="MultiObject{T1, T2, T3}"/> of <typeparamref name="T1"/>, <typeparamref name="T2"/> and <typeparamref name="T3"/> objects instances.
    /// </returns>
    public static MultiList<T1, T2, T3> New<T1, T2, T3>(IList<T1> first, IList<T2> second, IList<T3> third)
    {
        return new MultiList<T1, T2, T3>(first, second, third);
    }
}

#endregion

#region MultiList<T1, T2>

/// <summary>
/// Represents a 2-multi object, or pair.
/// </summary>
/// <typeparam name="T1">The type of the multi object's first component.</typeparam>
/// <typeparam name="T2">The type of the multi object's second component.</typeparam>
[SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Multi")]
public class MultiList<T1, T2> : MultiObject<IList<T1>, IList<T2>>
{
    /// <summary>
    /// Initializes a new instance of the <see cref="MultiList&lt;T1, T2&gt;"/> class.
    /// </summary>
    /// <param name="first">The first.</param>
    /// <param name="second">The second.</param>
    public MultiList(IList<T1> first, IList<T2> second) : base(first, second) { }
}

#endregion

#region MultiList<T1, T2, T3>

/// <summary>
/// Creates a new 3-multi object, or triple.
/// </summary>
/// <typeparam name="T1">The value of the first component of the multi object.</typeparam>
/// <typeparam name="T2">The value of the second component of the multi object.</typeparam>
/// <typeparam name="T3">The value of the third component of the multi object.</typeparam>
[SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Multi")]
[SuppressMessage("Microsoft.Design", "CA1005:AvoidExcessiveParametersOnGenericTypes")]
public class MultiList<T1, T2, T3> : MultiObject<IList<T1>, IList<T2>, IList<T3>>
{
    /// <summary>
    /// Initializes a new instance of the <see cref="MultiList&lt;T1, T2, T3&gt;"/> class.
    /// </summary>
    /// <param name="first">The first.</param>
    /// <param name="second">The second.</param>
    /// <param name="third">The third.</param>
    public MultiList(IList<T1> first, IList<T2> second, IList<T3> third) : base(first, second, third) { }
}

#endregion

每個視圖的數據

但是在您要傳遞菜單的情況下，最好有一個基頁類，所有頁面都繼承自該頁面類，並且該頁面類提供所有常用屬性（菜單數據為一個）。

Answer 4

要在單個視圖中處理多個模型，我個人使用ViewBag。

請注意，如果您使用ViewBag，則會禁用從編譯器獲得的所有幫助，並且運行時錯誤/錯誤的發生可能性超過該屬性位於“普通”對象上並且編譯器會捕獲錯別字的情況。

這是使用動態對象的缺點，但是，還有許多其他優點。 在您的控制器中，您只需將數據/模型傳遞到ViewBag：

public ActionResult Index() {
            ViewBag.TopMenu = TopMenu();
            ViewBag.Student = Student();
            return View();
        }

然后在視圖中，將其調出：

@{
    ViewBag.Title = "Index_ViewBag";
}

<h2>Index View Bag</h2>

<table>
   <tr>
   @foreach (var menu in ViewBag.TopMenu) 
   {
      <td>
      <a href="@menu.URL">@menu.Name</a>
      </td>
   }
   </tr>
</table>

<p>
 <ul>
  @foreach (var student in ViewBag.Student) 
  {
   <li>
    <a href="@student.URL">@student.Name</a>
   </li>   
  }
 </ul>
</p>

Answer 5

還有另一種選擇，由一些MVC純粹主義者提出，但我發現它對我有用。 而不是在每個有“菜單”的頁面上包含兩個模型（我假設幾乎都是所有頁面），您可以在學生視圖中顯示您的菜單：

@Html.RenderAction("Menu");

這將調用它自己的動作，生成菜單視圖模型和“菜單”局部視圖。

對我來說，這是有道理的，但我知道很多人不喜歡它。

Answer 6

在.Net Framework 4.0中，您可以使用動態模型。

大致：

public class HomeController : Controller
{
    public ActionResult Index()
    {
        dynamic viewmodel = new ExpandoObject();
        viewmodel.Students = MyStudent();
        viewmodel.MenuItems = MyMenuItems();
        return View(mymodel);
    }
}

如何訪問視圖代碼：

@model dynamic

@foreach (Student student in Model.Students)
    }
        <h1>@student.Name</h1>
    }
@foreach (MenuItem menuItem in Model.MenuItems)
    {
        <h1>@menuItem.menuname</h1>
    }