asp.net-mvc - 复合 View 模型和更新模型

Question

在 POST 操作中未填充的值中缺少什么？

Controller

public ActionResult Index()
{
    var productPageViewModel = new ProductPageViewModel();

    productPageViewModel.ProductPageCriteria = BuildProductPageCriteriaViewModel();
    productPageViewModel.Products = GetProducts(productPageViewModel.ProductPageCriteria);

    return View(productPageViewModel);
}

[HttpPost]
public ActionResult Index(ProductPageViewModel productPageViewModel, FormCollection formCollection)
{
    // productPageViewModel is not populated with posted values of ProductPageCriteria.CategoryID, ProductPageCriteria.DepartmentID and ProductPageCriteria.PageSize
    // formCollection has correct values
    // Calling UpdateModel(productPageViewModel); has no affect - makes sense, the framework has already called it
    // Calling UpdateModel(productPageViewModel.ProductPageCriteria); populates the values.
    // The renderd form has names like CategoryID, DepartmentID unlike ProductPageCriteria.CategoryID, ProductPageCriteria.DepartmentID
    //     if the top model was passed to all partial views also.

    return View(productPageViewModel);
}

楷模

public class ProductPageCriteriaViewModel
{
    public const int DefaultPageSize = 15;

    public ProductPageCriteriaViewModel()
    {
        Categories = new List<Category>();
        Departments = new List<Department>();

        PageSize = DefaultPageSize;
    }

    [Display(Name = "Category")]
    public int? CategoryID { get; set; }
    [Display(Name = "Department")]
    public int DepartmentID { get; set; }
    [Display(Name = "Page Size")]
    public int? PageSize { get; set; }

    public List<Category> Categories { get; set; }
    public List<Department> Departments { get; set; }
}

public class ProductPageViewModel
{
    public ProductPageViewModel()
    {
        ProductPageCriteria = new ProductPageCriteriaViewModel();
        Products = new List<Product>();
    }

    public ProductPageCriteriaViewModel ProductPageCriteria { get; set; }
    public List<Product> Products { get; set; }
}

public class Product
{
    public int ProductID { get; set; }
    public string ProductName { get; set; }

    public Category Category { get; set; }
    public Department Department { get; set; }
}

public class Category
{
    public int CategoryID { get; set; }
    public string CategoryName { get; set; }
}

public class Department
{
    public int DepartmentID { get; set; }
    public string DepartmentName { get; set; }
}

查看Index.cshtml

@using (Html.BeginForm()) {
    @Html.ValidationSummary(true)

    @Html.Partial("_ProductCriteria", Model.ProductPageCriteria)

    @Html.Partial("_ProductList", Model.Products)
}

部分 View _ProductCriteria.cshtml

@model Mvc3Application4.Models.ProductPageCriteriaViewModel

<fieldset>
    <legend>Criteria</legend>

    <div class="editor-label">
        @Html.LabelFor(model => model.CategoryID)
    </div>
    <div class="editor-field">
        @Html.DropDownListFor(model => model.CategoryID, new SelectList(Model.Categories, "CategoryID", "CategoryName", Model.CategoryID), "--- All ---")
        @Html.ValidationMessageFor(model => model.CategoryID)
    </div>

    <div class="editor-label">
        @Html.LabelFor(model => model.DepartmentID)
    </div>
    <div class="editor-field">
        @Html.DropDownListFor(model => model.DepartmentID, new SelectList(Model.Departments, "DepartmentID", "DepartmentName", Model.DepartmentID), "--- All ---")
        @Html.ValidationMessageFor(model => model.DepartmentID)
    </div>

    <div class="editor-label">
        @Html.LabelFor(model => model.PageSize)
    </div>
    <div class="editor-field">
        @Html.DropDownListFor(model => model.PageSize, new SelectList(new List<int> {10, 15, 20, 25, 50, 100}.Select(n => new {Value = n, Text = n}), "Value", "Text", Model.PageSize), "--- All ---")
        @Html.ValidationMessageFor(model => model.PageSize)
    </div>

    <p>
        <input type="submit" value="Search" />
    </p>
</fieldset>

部分 View _ProductList.cshtml

@model IEnumerable<Mvc3Application4.Models.Product>

<p>
    @Html.ActionLink("Create New", "Create")
</p>
<table>
    <tr>
        <th></th>
        <th>
            ProductName
        </th>
    </tr>

@foreach (var item in Model) {
    <tr>
        <td>
            @Html.ActionLink("Edit", "Edit", new { id=item.ProductID }) |
            @Html.ActionLink("Details", "Details", new { id=item.ProductID }) |
            @Html.ActionLink("Delete", "Delete", new { id=item.ProductID })
        </td>
        <td>
            @item.ProductName
        </td>
    </tr>
}

</table>

Answer 1

这是我的头脑和未经测试的顶部，但我相信如果您将父模型( ProductPageViewModel )传递给产品标准局部 View ，更改局部 View 以继承此模型，并将控件更改为从 model => model.ProductPageCriteria.CategoryID 而不是 model => model.CategoryID ，它应该保持命名，以便 UpdateModel 可以将字段与发布的值匹配。

对不起，我的极端连续句子，如果这是不正确的，我相信我会很快获得我的同伴压力徽章。 :) 希望这可以帮助。