将模型数据从视图传递到控制器
我想通过HttpPost将模型数据从视图(和视图内的PartialView)传递回控制器。 (改编自Pass SelectedValue of DropDownList in Html.BeginForm() in ASP.NEt MVC 3)将模型数据从视图传递到控制器
为什么?我想显示每个具有DropDownList和多个选项的资产列表。提交表单以从DropDownList中读取所选项目。
我2(简体)型号:
public class Booking
{
public int BookingID { get; set; }
public int StoreID { get; set; }
...
public IEnumerable<AssetShort> Assets { get; set; }
}
和
public class AssetShort
{
public int AssetID { get; set; }
....
public int SelectedAction { get; set; }
public IEnumerable<SelectListItem> ActionList { get; set; }
}
在我的预订控制器>创建我生成列表:
public ActionResult Booking(int id)
{
// get myBag which contains a List<Asset>
// booking corresponds to 'id'
var myAssets = new List<AssetShort>();
foreach (var a in myBag.Assets)
{
var b = new AssetShort();
b.AssetID = a.ID;
b.SelectedAction = 0;
b.ActionList = new[]
{
new SelectListItem { Selected = true, Value = "0", Text = "Select..."},
new SelectListItem { Selected = false, Value = "1", Text = "Add"},
new SelectListItem { Selected = false, Value = "2", Text = "Remove"},
new SelectListItem { Selected = false, Value = "3", Text = "Relocate"},
new SelectListItem { Selected = false, Value = "4", Text = "Upgrade"},
new SelectListItem { Selected = false, Value = "5", Text = "Downgrade"}
};
myAssets.Add(b);
};
var model = new BookingRequirementsViewModel
{
BookingID = booking.ID,
StoreID = booking.StoreID,
Assets = myAssets.ToList(),
};
return View(model);
笔者认为:
@model uatlab.ViewModels.BookingRequirementsViewModel
@{
ViewBag.Title = "Booking step 2";
}
<h4>Your booking ref. @Model.BookingID</h4>
@using (Html.BeginForm("Booking2", "Booking", FormMethod.Post))
{
<fieldset>
@Html.AntiForgeryToken()
@Html.HiddenFor(model => model.StoreID)
@Html.Partial("_Assets", Model.StoreAssets)
<input type="submit" value="Cancel" class="btn btn-default" />
<input type="submit" value="Next" class="btn btn-default" />
</fieldset>
}
局部视图包括
@foreach (var item in Model)
{
<tr>
<td>@item.Name</td>
<td>@item.Number</td>
<td>@Html.DropDownListFor(modelItem=>item.SelectedAction, item.ActionList)</td>
</tr>
}
所以,这一切工作正常,在浏览器中,我可以列出的每个资产选择的下拉列表中,但是当我提出调回唯一的价值是STOREID因为它是在一个“ HiddenFor”。
的booking2控制器有一个参数型号:
public ActionResult Booking2(BookingRequirementsViewModel model)
{
//loop through model.Assets and display SelectedActions
}
让我说清楚的问题是 - 在Booking2控制器的型号为NULL在调试模式下查看时,我得到错误“对象引用未设置为对象的实例。“
任何想法,请如何从视图回传模型到控制器?
问候 克雷格
你需要创建一个AssetShort
EditorTemplate
。我还建议把ActionList
到BookingRequirementsViewModel
所以你不能再生每个AssetShort
您发布不决策意识的车型新SelectList
。您的控制器有var model = new BookingRequirementsViewModel { ..., Assets = myAssets.ToList() };
,但在您看来您指的是@Html.Partial("_Assets", Model.StoreAssets)
?这两个不同的属性。我会认为StoreAssets
是IEnumerable<AssetShort>
/Views/Shared/EditorTemplates/AssetShort.cshtml
@model AssetShort
<tr>
<td>@Html.DispayFor(m => m.Name)</td>
....
<td>
@Html.DropDownListFor(m => m.SelectedAction, (IEnumerable<SelectListItem>)ViewData["actionList"], "--Please select--")
@Html.ValidationMessageFor(m => m.SelectedAction)
</td>
</tr>
在主视图
@model uatlab.ViewModels.BookingRequirementsViewModel
....
@using (Html.BeginForm()) // Not sure why you post to a method with a different name
{
....
@Html.HiddenFor(m => m.StoreID)
@Html.EditorFor(m => m.StoreAssets, new { actionList = Model.ActionList })
....
}
在控制器
public ActionResult Booking(int id)
{
....
var model = new BookingRequirementsViewModel
{
BookingID = booking.ID,
StoreID = booking.StoreID,
Assets = myBag.Assets.Select(a => new AssetShort()
{
AssetID = a.ID,
SelectedAction = a.SelectedAction, // assign this if you want a selected option, otherwise the "--Please select--" option will be selected
....
})
};
ConfigureViewModel(model); // Assign select list
return View(model);
}
而且一个单独的方法来生成SelectList
因此如果您返回视图,则需要在GET方法中调用它,并在POST方法中再次调用它。注意使用的DropDownListFor()
过载以生成选项标签(空值)如上,并且没有点设置Selected
属性(的SelectedAction
值确定什么被选择时,没有此)
private ConfigureViewModel(BookingRequirementsViewModel model)
{
model.ActionList = new[]
{
new SelectListItem { Value = "1", Text = "Add"},
....
new SelectListItem { Value = "5", Text = "Downgrade"}
};
}
和POST
public ActionResult Booking(BookingRequirementsViewModel model)
{
if (!ModelState.IsValid)
{
ConfigureViewModel(model); // Re-assign select list
return View(model);
}
// save and redirect
}
我建议也正在与[Required]
属性SelectedAction
为空的,所以你得到的客户端和服务器端验证
public class AssetShort
{
public int AssetID { get; set; }
....
[Required]
public int? SelectedAction { get; set; }
}
Stephen 请问一个问题... 预订控制器中用于填写BookingRequirementsModel模型: SelectedAction = a.SelectedAction, 这看起来像我需要Assets模型中的SelectedAction,我目前还没有。 是吗? 问候 – 2014-12-19 09:21:39
我只是假设你有它。如果你实际上没有将所选选项的值保存到数据库中,那么我想你不需要它,但是在那种情况下,它在'AssetShort'中的实际用途是什么? – 2014-12-19 09:27:53
谢谢,让它工作。 – 2014-12-19 10:15:04
您无法使用部分来在集合中生成控件。如果你检查html,你会看到你有'name'属性重复(以及重复的'id'属性是无效的html)。您需要在主视图中使用'for'循环,或者为'Assets'使用自定义的'EditorTemplate'。 – 2014-12-18 23:05:24