在我的网络应用程序中发生了一些奇怪的事情，我无法找到原因。请帮助我或者让我知道如何解决这个挑战。相同的代码在某些情况下适用于另一个我得到空引用异常。 在控制器中，我从DB获得特定类别的模型。然后，在视图中我列出了此类别中的所有产品。当我从列表中选择一些产品并按“购物车”按钮时，有时模型会正确传递/传输到控制器，有时模型中的产品为空。
我的控制器操作：
[HttpGet]
[PacCheckPermissionAttribute(PacPermissionRecordEnum.perm_pubmatorder)]
public ActionResult PacCategoryDetails(int categoryId)
{
Category category = _categoryService.GetCategoryById(categoryId);
if(category == null || category.Deleted || !category.Published)
return RedirectToRoute("HomePage");
CategoryModel model = prepareCategoryModel(category, false);
return View(model);
}
[HttpPost]
[PacCheckPermissionAttribute(PacPermissionRecordEnum.perm_pubmatorder)]
public ActionResult PacCategoryDetails(CategoryModel model)
{
Category category = _categoryService.GetCategoryById(model.Id);
if (category == null || category.Deleted || !category.Published)
return RedirectToRoute("HomePage");
//Add the selected Products to ShoppingCart
for (int i = 0; i < model.Products.Count; i++)
...
model.Products有时是null，有时是正确的 - 不知道为什么??? 我的观点：
@model CategoryModel
@using Nop.Web.Models.Catalog;
@using Nop.Core.Domain.Orders;
@using Nop.Web.Framework;
@using Nop.Web.Models.ShoppingCart;
@using PacControls;
@using Telerik.Web.Mvc.UI;
@{
Html.AppendScriptParts(@Url.Content("~/Administration/Scripts/jquery.validate.unobtrusive.min.js"));
Html.AppendScriptParts(@Url.Content("~/Administration/Scripts/jquery.validate.min.js"));
Html.AppendScriptParts(@Url.Content("~/Administration/Scripts/jquery.unobtrusive-ajax.min.js"));
Layout = "~/Views/Shared/_PacLoggedIn.cshtml";
}
@section SideBar
{
@Html.Action("PacCategoryNavigation", "Catalog", new { currentCategoryId = Model.Id})
}
@using (Html.BeginForm())
{
<div class="productdetails-page">
<div class="body">
<div class="info-row">
<div class="productlist-content">
<div class="info-row">
<div class="box border-r box-s info-row category-details">
<!-- <div class="f-l" style="width: 320px;">@Html.Partial("_ProductDetailsPictures", Model)</div> -->
<div class="f-l" style="width: 360px;"><h1>@Html.DisplayTextFor(x => Model.Name)</h1>
@Html.Raw(Model.Description)
@Html.HiddenFor(x => Model.Id)
</div>
<div class="f-c"></div>
</div>
<div class="f-c"></div>
</div>
<div class="f-c"></div>
@if (Model.Products.Count > 0)
{
<div class="titelbox border-top-r-l full-row darkgrey-background">
<div class="page-title">
<h3>@T("Pac.PromotionMaterial")</h3>
</div>
</div>
<div class="box border-bottom-r-l info-row">
<div class="osc-data">
<div class="osc-table">
<div class="mm-items">
@for (int i = 0; i < Model.Products.Count; i++)
{
if (!Model.Products[i].IsDownload)
{
<div class="mm-row" id="@(i)">
@Html.HiddenFor(x => Model.Products[i].Id)
<div class="mm-col quanity-col">
<div>
@Html.EditorFor(x => Model.Products[i].Quantity)
@Html.ValidationMessageFor(x => Model.Products[i].Quantity)
</div>
</div>
<div class="mm-col name-col">
<div id="name_@(i)">
@Html.DisplayTextFor(x => Model.Products[i].Name)
</div>
</div>
<div class="mm-col price-col">
<div>
<div id="price_@(i)" class="price-col">@Html.DisplayTextFor(x => @Model.Products[i].ProductPrice.Price)</div>
<input type="hidden" id="pricevalue_@(i)" value="@(Model.Products[i].ProductPrice.PriceValue)"/>
</div>
</div>
<div class="f-c"></div>
</div>
}
}
</div>
</div>
</div>
</div>
}
@if (Model.Products.Count > 0)
{
<div class="titelbox border-top-r-l full-row darkgrey-background">
<div class="page-title">
<h3>@T("Pac.Download")</h3>
</div>
</div>
<div class="box border-bottom-r-l info-row">
<div class="osc-data">
<div class="osc-table">
<div class="mm-items">
@for (int i = 0; i < Model.Products.Count; i++)
{
if (Model.Products[i].IsDownload)
{
<div class="mm-row" id="@(i)">
<div class="mm-col downloadname-col">
<div>
@Html.DisplayTextFor(x => Model.Products[i].Name)
</div>
</div>
<div class="mm-col downloadbutton-col">
@if (Model.Products[i].IsDownload)
{
@Html.SmallButton(T("Pac.Button.Download").Text, ButtonStyle.Default, "location.href = '" +Url.RouteUrl("GetProductDownload", new { productvariantid = Model.Products[i].ProductVariantId }) + "';return false;" , new Dictionary<string, object>() { { "class", "smallbuttoncart" } })
}
</div>
<div class="f-c"></div>
</div>
}
}
</div>
</div>
</div>
</div>
}
<div class="titelbox border-top-r-l full-row darkgrey-background">
<div class="page-title darkgrey-background">
<h3>@T("Pac.Summary")</h3>
</div>
</div>
<div class="box border-bottom-r-l info-row">
<div class="osc-data">
<div class="osc-table">
<div class="mm-items" id="summarytable">
</div>
</div>
</div>
</div>
</div>
<div class="f-c"></div>
<div class="f-r full-row right">
@Html.SubmitButton(T("Pac.Button.ToShoppingCart").Text, ButtonStyle.Lightgrey)
</div>
<div class="f-c "></div>
</div>
</div>
</div>
}
<script type="text/javascript" language="javascript">
var summaryrow = "<div class=\"mm-row mm-summaryrow\"><div class=\"mm-col summaryquantity-col\" id=\"summaryrow\"></div><div class=\"mm-col summaryname-col\">@T("Pac.Price")</div><div class=\"mm-col summaryprice-col\">#price#</div><div class=\"f-c\"></div></div>";
var elementrow = "<div class=\"mm-row\" id=\"summaryrow_\"><div class=\"mm-col summaryquantity-col\" id=\"summaryquanity_\">#quantity#</div><div class=\"mm-col summaryname-col\" id=\"summaryname_\">#name#</div><div class=\"mm-col summaryprice-col\" id=\"summaryprice_\">#price#</div><div class=\"f-c\"></div></div>";
function calculateSummary() {
var sum = 0.00;
var position = 0;
$('#summarytable').empty();
$('input[id$="Quantity"]').each(
function () {
//summ price
var id = this.id.substring(this.id.indexOf("[")+1, this.id.indexOf("]"));
var price = $('#pricevalue_' + id)[0].value.replace(",",".");
var quantity = this.value;
var val = 0;
if(!isNaN(quantity) && !isNaN(price) && quantity > 0)
{
val = parseFloat(quantity) * parseFloat(price);
sum = sum + val;
//Create new Row
var newrow = elementrow;
newrow = newrow.replace("#quantity#", this.value);
newrow = newrow.replace("#name#", $('#name_' + id)[0].innerHTML);
newrow = newrow.replace("#price#", val.toFixed(2).replace(".",",") + " (EUR)");
newrow = newrow.replace("summaryrow_", "summaryrow_" + id);
newrow = newrow.replace("summaryquanity_", "summaryquanity_" + id);
newrow = newrow.replace("summaryname_", "summaryname_" + id);
newrow = newrow.replace("summaryprice_", "summaryprice_" + id);
//add row to summarytable
$('#summarytable').append(newrow);
}
}
);
var newsummaryrow = summaryrow;
newsummaryrow = newsummaryrow.replace("#price#", sum.toFixed(2).replace(".",",") + " (EUR)");
$('#summarytable').append(newsummaryrow);
}
function addOnUpdateFunctions()
{
$('input[id$="Quantity"]').each(
function () {
this.setAttribute("onchange", "calculateSummary();");
});
$("a[class^='t-link t-icon t-arrow-']").each(
function () {
this.setAttribute("onclick", "calculateSummary();");
});
}
$(document).ready(calculateSummary());
$(document).ready(addOnUpdateFunctions());
</script>
@(Html.Telerik().StyleSheetRegistrar()
.DefaultGroup(group => group
.Add("telerik.common.min.css")
.Add("telerik.vista.min.css")
.Add("telerik.rtl.min.css")
))
@(Html.Telerik().ScriptRegistrar()
.jQuery(false)
.jQueryValidation(false)
)
知道发生了什么事吗？感谢名单！
答案 0 :(得分：0)
您有两个条件阻止产品列在<form>：
if (Model.Products.Count > 0)
和
if (Model.Products[i].IsDownload)
因此，如果或类别中没有产品，则没有可下载的产品，那么Products在发布时将为null 。这是预期的行为。只需检查null并执行您需要执行的操作。在这种情况下，我会说你可能只是忽略它，因为没有产品可以添加到购物车中，而且用户可能只是错误地点击了它。