【发布时间】：2018-04-09 07:53:55
【问题描述】：
我有一个这样的 ViewModel：
public class AddNewsModel
{
public List<CategoriesModel> Category { get; set; }
public NewsModel NewsModel { get; set; }
}
其中类别包含：
public class CategoriesModel
{
public string Name { get; set; }
public int ID { get; set; }
}
NewsModel 包含：
public class NewsModel
{
public int ID { get; set; }
public string Category { get; set; }
public String Headline { get; set; }
public string Source { get; set; }
public DateTime Publish_Date { get; set; }
public string Text { get; set; }
public string Summary { get; set; }
public string TimeAgo { get; set; }
public string ImageURL { get; set; }
public string CategoryID { get; set; }
}
我有一个视图，我在其中使用 NewsModel 为新闻获取表单输入，但我想将可能的类别显示为下拉列表或从 CategoriesModel 中选择标签。
这是我的观点：
<h2>Add a News Article</h2>
@if (TempData["Success"] != null)
{
<p class="alert alert-success" id="successMessage">@TempData["Success"]</p>
}
@using (Html.BeginForm("AddNews", "Admin", FormMethod.Post))
{
@Html.AntiForgeryToken()
<div class="form-horizontal" id="addNews">
<hr />
@Html.ValidationSummary(true, "", new { @class = "text-danger" })
<div class="form-group">
@Html.Label("News ID", htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-1">
@Html.EditorFor(model => model.NewsModel.ID, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.NewsModel.ID, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.NewsModel.Category, htmlAttributes: new { @class = "control-label col-md-2" })
@Html.DropDownListFor(model => model.Category, new SelectList(Model.Category), "Select Category")
@*<div class="col-md-2">
<select form="addNews" id="NewsModel_Category" name="NewsModel.Category">
@foreach (var item in Model.Category)
{
<option value="@item.Name">@item.Name</option>
}
</select>
</div>*@
</div>
<div class="form-group">
@Html.LabelFor(model => model.NewsModel.Headline, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-6">
@Html.EditorFor(model => model.NewsModel.Headline, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.NewsModel.Headline, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.NewsModel.Source, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-6">
@Html.EditorFor(model => model.NewsModel.Source, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.NewsModel.Source, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.Label("Publish Date", htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-4">
@Html.EditorFor(model => model.NewsModel.Publish_Date, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.NewsModel.Publish_Date, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.NewsModel.Text, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-6">
@Html.TextAreaFor(model => model.NewsModel.Text, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.NewsModel.Text, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.NewsModel.Summary, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-6">
@Html.TextAreaFor(model => model.NewsModel.Summary, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.NewsModel.Summary, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.NewsModel.ImageURL, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-6">
@Html.EditorFor(model => model.NewsModel.ImageURL, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.NewsModel.ImageURL, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="submit" value="Create" class="btn btn-default" />
</div>
</div>
</div>
}
这行代码：
@Html.DropDownListFor(model => model.Category, new SelectList(Model.Category), "Select Category")
获取所有类别，但仅将它们显示为我在视图中导入的模型，即。 “MVCApplication.Models.AddNewsModel”，而不是像“World”或“Tech”这样的类别
当我尝试使用 formcollection 在我的 HTTPPost 控制器操作中获取数据时，我评论过的这段代码返回 null。我尝试使用我提供的 ID：string x= formCollection["category"];
<div class="col-md-2">
<select form="addNews" id="category" name="category">
@foreach (var item in Model.Category)
{
<option value="@item.Name">@item.Name</option>
}
</select>
</div>
如何在我的视图中显示类别，以及在控制器中获取值？ 任何帮助将不胜感激。
编辑：
我将控制器操作中的类别列表填充为：
public ActionResult AddNews()
{
AddNewsModel AddNewsModel = new AddNewsModel();
AddNewsModel.Categories = new NewsArticles().GetCategories();
return View(AddNewsModel);
}
将我的模型更改为 Ienumerable 而不是列表会导致我的控制器出现错误，我似乎无法解决。
【问题讨论】：
-
new SelectList(Model.Category, "Id", "Name")（但您的视图模型应该包含属性IEnumerable<SelectListItem> CategoryList，而不是List<CategoriesModel>）。并且您不能对要绑定的属性和 SelectList 使用相同的名称。必须是@Html.DropDownListFor(m => m.NewsModel.Category, ...) -
我尝试了这个以及@Irakli 的答案在我的控制器操作中明确投射后，它可以工作
标签： asp.net-mvc viewmodel