c# - 需要将 List 传递给 Controller ​​中的 Http Post

Question

我正在将一个列表传递给 View 。在 View 中我需要传回该列表。它包括一个可编辑的复选框，这是我真正需要的项目。显示的所有其他字段仅供只读用途。如果用户想要将该项目指定为间隙，那么他们会选中 isClearance 复选框。因此，当他们点击保存按钮时，它会点击 HttpPost Index()。然而，它传回一个空值。如果我将其更改为模型对象，而不是列表，它就可以正常工作。

这是 Controller 索引:

 public ActionResult Index()
    {
        List<ClearanceViewModel> cc = new List<ClearanceViewModel>();
        ClearanceViewModel c = new ClearanceViewModel();
        c.sku = "123";
        c.title = "Test1";
        c.includeOnSite = true;
        c.productID = 123;
        c.salePrice = Convert.ToDecimal(2.99);
        c.RetailPrice = Convert.ToDecimal(4.99);
        c.isClearance = false;
        cc.Add(c);

        c.sku = "123";
        c.title = "Test1";
        c.includeOnSite = true;
        c.productID = 123;
        c.salePrice = Convert.ToDecimal(2.99);
        c.RetailPrice = Convert.ToDecimal(4.99);
        c.isClearance = false;
        cc.Add(c);

        return View(cc);
    }

这是 View :

@model List<PMS.Models.ClearanceViewModel>
@{    
ViewBag.title = "Clearance List";    
}
<fieldset>
<legend><span>Clearance List</span></legend>
@using (Html.BeginForm())
{
if (Model.Count() > 0)
{    
    <table class="list">
        <tr> 
            <th>Sku</th>
            <th>Title</th>
            <th>Include On Site</th>
            <th>Sale price</th>
            <th>Retail Price</th>
            <th>Quantity</th>
            <th>Clearance</th>
        </tr>
        @foreach(var item in Model)
        {
            @Html.HiddenFor(modelItem => item.productID);
            <tr>    
                <td>@Html.DisplayFor(modelItem => item.sku)</td>
                <td>@Html.DisplayFor(modelItem => item.title)</td>
                <td>@Html.DisplayFor(modelItem => item.includeOnSite)</td>
                <td>@Html.DisplayFor(modelItem => item.salePrice)</td>
                <td>@Html.DisplayFor(modelItem => item.RetailPrice)</td>
                <td>@Html.DisplayFor(modelItem => item.quantity)</td>
                <td>@Html.EditorFor(modelItem => item.isClearance)</td>        
            </tr>
        }
    </table>
   <p>
            <input type="submit" value="Save" />
    </p>

}
}
</fieldset>

这是 Controller 中的 HttpPost(当它遇到 foreach 循环时，clearanceModel 为 null，此时它应该有一个项目列表):

        [HttpPost]
    public ActionResult Index(List<ClearanceViewModel> clearanceModel)
    {
        foreach (ClearanceViewModel item in clearanceModel)
        {
            if (item.isClearance == true)
            {
                // get the product object, so we can add it to the product Promotion of                      clearance
                var product = _unitOfWork.ProductRepository.Get(filter: p => p.productID == item.productID).FirstOrDefault();

                // Make sure that it isn't already in the product promotion for clearance
                var productPromotion = _unitOfWork.ProductPromotionRepository.Get(filter: pp => pp.productID == product.productID && pp.promotion.Name == "Clearance").FirstOrDefault();

                //add the product promotion
                if (productPromotion == null)
                {
                    // get the clearance promotion
                    var promotion = _unitOfWork.PromotionRepository.Get(filter: pr => pr.Name == "Clearance").FirstOrDefault();
                    if (promotion != null)
                    {
                        ProductPromotion promo = new ProductPromotion();
                        promo.productID = product.productID;
                        promo.promotionID = promotion.promotionID;
                        promo.onDate = DateTime.Now;
                        promo.offDate = null;
                        promo.canOverwrite = true;
                        _unitOfWork.ProductPromotionRepository.Create(promo);
                        _unitOfWork.SaveChanges();
                    }
                }
            }
        }

Answer 1

模型绑定(bind)不适用于 foreach 循环。您必须使用 for 循环。这样，索引器 [i] 用于为生成的 html 中的每个输入元素创建唯一的名称属性。

@for (int i = 0; i < Model.Count; i++)
        {
            @Html.HiddenFor(modelItem => modelItem[i].productID);
            <tr>    
                <td>@Html.DisplayFor(modelItem => modelItem[i].sku)</td>
                <td>@Html.DisplayFor(modelItem => modelItem[i].title)</td>
                <td>@Html.DisplayFor(modelItem => modelItem[i].includeOnSite)</td>
                <td>@Html.DisplayFor(modelItem => modelItem[i].salePrice)</td>
                <td>@Html.DisplayFor(modelItem => modelItem[i].RetailPrice)</td>
                <td>@Html.DisplayFor(modelItem => modelItem[i].quantity)</td>
                <td>@Html.EditorFor(modelItem => modelItem[i].isClearance)</td>        
            </tr>
        }

有关模型绑定(bind)集合的详细说明，请查看 this article