c# - MVC View Viewmodel HttpPost 返回 NULL
问题描述
出于某种原因,我传递的 ViewModel 在 HttpPost 的控制器中返回 NULL,但我不知道为什么。我以为我用@Html.HiddenFor(modelItem => product.Id) 限制了视图中的模型。
我的观点:
@model MaterialOrderFinal.Models.ProductViewmodel
@{
ViewBag.Title = "Index";
}
@using (Html.BeginForm("Result", "Product", FormMethod.Post))
{
foreach (var category in Model.ProductCategories)
{
<div class="panel panel-default">
<div class="panel-heading">
<h4 class="panel-title">
<a data-toggle="collapse" href="@($"#collapse{category.Id}")">
@Html.DisplayFor(modelItem => category.Name)
</a>
</h4>
</div>
<div id="@($"collapse{category.Id}")" class="panel-collapse collapse">
<div class="panel-body">
@foreach (var product in Model.Products.Where(product => product.ProductCategoryId == category.Id))
{
<div class="col-sm-6">
<div class="col-xs-6">
@Html.DisplayFor(modelItem => product.Name) <br />
@Html.DisplayFor(modelItem => product.Description)
@Html.HiddenFor(modelItem => product.Id)
@Html.HiddenFor(modelItem => product.Name)
</div>
<div class="col-xs-6">
@Html.RadioButtonFor(modelItem => product.Quantity, 0, new { Name = product.Id, id = product.Id }) <span>0</span> <br />
@Html.RadioButtonFor(modelItem => product.Quantity, 50, new { Name = product.Id, id = product.Id }) <span>50</span> <br />
@Html.RadioButtonFor(modelItem => product.Quantity, 100, new { Name = product.Id, id = product.Id }) <span>100</span> <br />
@Html.RadioButtonFor(modelItem => product.Quantity, 200, new { Name = product.Id, id = product.Id }) <span>200</span>
</div>
</div>
}
</div>
</div>
</div>
}
<input type="submit" class="btn btn-default" />
}
我的控制器:
public class ProductController : Controller
{
private MaterialOrderContext db = new MaterialOrderContext();
// GET: Product
public ActionResult Index()
{
var products = db.Products.Include(p => p.ProductCategory).ToList();
var productCategories = db.ProductCategories.ToList();
var viewModel = new ProductViewmodel { Products = products, ProductCategories = productCategories };
return View(viewModel);
}
[HttpPost]
public ActionResult Result(ProductViewmodel viewModel)
{
var products = viewModel.Products;
Debug.WriteLine(products.ToString()); // Returns NULL here!
return View(products);
}
}
我的视图模型:
public class ProductViewmodel
{
public IEnumerable<Product> Products { get; set; }
public IEnumerable<ProductCategory> ProductCategories { get; set; }
}
显示包含我的类别和产品的初始网站,但是一旦我单击提交按钮,我就会收到 NullReferenceError。
解决方案
您需要手动创建输入字段并name
相应地设置属性:
<input name="Products[0].Name" />
<input name="Products[0].Id" />
<input name="Products[1].Name" />
<input name="Products[1].Id" />
试试这个代码:
@using (Html.BeginForm("Result", "Product", FormMethod.Post))
{
int index = 0;
foreach (var category in Model.ProductCategories)
{
<div class="panel panel-default">
<div class="panel-heading">
<h4 class="panel-title">
<a data-toggle="collapse" href="@($"#collapse{category.Id}")">
@Html.DisplayFor(modelItem => category.Name)
</a>
</h4>
</div>
<div id="@($"collapse{category.Id}")" class="panel-collapse collapse">
<div class="panel-body">
@foreach (var product in Model.Products.Where(product => product.ProductCategoryId == category.Id))
{
<input type="hidden" name="Proucts[@index].Id" value="@product.Id" />
<input type="hidden" name="Proucts[@index].Name" value="@product.Name" />
<div class="col-sm-6">
<div class="col-xs-6">
@Html.DisplayFor(modelItem => product.Name) <br />
@Html.DisplayFor(modelItem => product.Description)
</div>
<div class="col-xs-6">
<input type="radio" name="Products[@index].Quantity" value="0" /> <span>0</span> <br />
<input type="radio" name="Products[@index].Quantity" value="50" /> <span>50</span> <br />
<input type="radio" name="Products[@index].Quantity" value="100" /> <span>100</span> <br />
<input type="radio" name="Products[@index].Quantity" value="200" /> <span>200</span>
</div>
</div>
index++;
}
</div>
</div>
</div>
}
<input type="submit" class="btn btn-default" />
}
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