C# 具有ViewModel MVC4的FK约束
我在使用MVC4和实体框架时遇到了一些问题。我有一个实体“Person”,它由另一个名为“ProductPackageCategories”的实体组成。我还有一个ViewModel“PersonViewModel”。在“CreatePerson”视图中,我可以创建我的新Person并使用dropdownlist组件指定类别。通常,当我单击submit按钮时,数据存储在数据库中。在我的例子中,我检索所有数据,但不检索ProductPackageCategory Id。有人知道这个问题吗 异常消息:C# 具有ViewModel MVC4的FK约束,c#,asp.net-mvc,viewmodel,C#,Asp.net Mvc,Viewmodel,我在使用MVC4和实体框架时遇到了一些问题。我有一个实体“Person”,它由另一个名为“ProductPackageCategories”的实体组成。我还有一个ViewModel“PersonViewModel”。在“CreatePerson”视图中,我可以创建我的新Person并使用dropdownlist组件指定类别。通常,当我单击submit按钮时,数据存储在数据库中。在我的例子中,我检索所有数据,但不检索ProductPackageCategory Id。有人知道这个问题吗 异常消息:
The INSERT statement conflicted with the FOREIGN KEY constraint "FK_bm_Persons_bm_ProductPackageCategories". The conflict occurred in database "C:\USERS\MAARAB\DESKTOP\PROJECT\2013-03-01_4-9_MA-OS_BUSI MATERIAL PROJECT\BUSIMATERIAL\BUSIMATERIAL\APP_DATA\BUSIMATERIAL.MDF", table "dbo.bm_ProductPackageCategories", column 'Id_ProductPackageCategory'.
声明已终止
我在PersonController中的创建操作:
public ActionResult Create()
{
ViewBag.Id_ProductPackageCategory = new SelectList(db.ProductPackageCategories, "Id_ProductPackageCategory", "Name");
return View();
}
//
// POST: /Person/Create
[HttpPost]
public ActionResult Create(PersonViewModel personViewModel)
{
if (ModelState.IsValid)
{
db.Persons.AddObject(personViewModel.person);
db.SaveChanges();
return RedirectToAction("Index");
}
ViewBag.Id_ProductPackageCategory = new SelectList(db.ProductPackageCategories, "Id_ProductPackageCategory", "Name", personViewModel.person.Id_ProductPackageCategory);
return View(personViewModel);
}
我的ViewModel:
public class PersonViewModel
{
public Person person { get; set; }
public PersonViewModel()
{
person = new Person();
}
public PersonViewModel(Person person)
{
this.person = person;
}
}
我的创建视图:
@model BuSIMaterial.Models.PersonViewModel
@{
ViewBag.Title = "Create";
}
<h2>Create</h2>
@using (Html.BeginForm()) {
@Html.ValidationSummary(true)
<fieldset>
<legend>Person</legend>
<div class="editor-label">
@Html.LabelFor(model => model.person.FirstName)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.person.FirstName)
@Html.ValidationMessageFor(model => model.person.FirstName)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.person.LastName)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.person.LastName)
@Html.ValidationMessageFor(model => model.person.LastName)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.person.NumNat)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.person.NumNat)
@Html.ValidationMessageFor(model => model.person.NumNat)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.person.StartDate)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.person.StartDate)
@Html.ValidationMessageFor(model => model.person.StartDate)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.person.EndDate)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.person.EndDate)
@Html.ValidationMessageFor(model => model.person.EndDate)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.person.Upgrade)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.person.Upgrade)
@Html.ValidationMessageFor(model => model.person.Upgrade)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.person.Id_ProductPackageCategory, "Category")
</div>
<div class="editor-field">
@Html.DropDownList("Id_ProductPackageCategory", "Choose one...")
@Html.ValidationMessageFor(model => model.person.Id_ProductPackageCategory)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.person.HouseToWorkKilometers)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.person.HouseToWorkKilometers)
@Html.ValidationMessageFor(model => model.person.HouseToWorkKilometers)
</div>
<p>
<input type="submit" value="Create" />
</p>
</fieldset>
}
<div>
@Html.ActionLink("Back to List", "Index")
</div>
@section Scripts {
@Scripts.Render("~/bundles/jqueryval")
}
@model.material.Models.PersonViewModel
@{
ViewBag.Title=“创建”;
}
创造
@使用(Html.BeginForm()){
@Html.ValidationSummary(true)
人
@LabelFor(model=>model.person.FirstName)
@EditorFor(model=>model.person.FirstName)
@Html.ValidationMessageFor(model=>model.person.FirstName)
@LabelFor(model=>model.person.LastName)
@EditorFor(model=>model.person.LastName)
@Html.ValidationMessageFor(model=>model.person.LastName)
@LabelFor(model=>model.person.NumNat)
@EditorFor(model=>model.person.NumNat)
@Html.ValidationMessageFor(model=>model.person.NumNat)
@LabelFor(model=>model.person.StartDate)
@EditorFor(model=>model.person.StartDate)
@Html.ValidationMessageFor(model=>model.person.StartDate)
@LabelFor(model=>model.person.EndDate)
@EditorFor(model=>model.person.EndDate)
@Html.ValidationMessageFor(model=>model.person.EndDate)
@LabelFor(model=>model.person.Upgrade)
@EditorFor(model=>model.person.Upgrade)
@Html.ValidationMessageFor(model=>model.person.Upgrade)
@Html.LabelFor(model=>model.person.Id\u ProductPackageCategory,“Category”)
@Html.DropDownList(“Id\u ProductPackageCategory”,“选择一个…”)
@Html.ValidationMessageFor(model=>model.person.Id\u ProductPackageCategory)
@LabelFor(model=>model.person.housetoworkkm)
@EditorFor(model=>model.person.housetoworkkm)
@Html.ValidationMessageFor(model=>model.person.houseToworkkm)
}
@ActionLink(“返回列表”、“索引”)
@节脚本{
@Scripts.Render(“~/bundles/jqueryval”)
}
更换:
@Html.DropDownList("Id_ProductPackageCategory", "Choose one...")
与:
这样,当表单提交到HttpPost操作时,模型上的
person.Id\u ProductPackageCategory
属性将从下拉列表中的选定值正确绑定。使用强类型html帮助程序将属性绑定到模型。使用DropDownListFor
代替DropDownList
控制器
public ActionResult Create()
{
ViewBag.Id_ProductPackageCategory = new SelectList(db.ProductPackageCategories, "Id_ProductPackageCategory", "Name");
return View();
}
看法
谢谢你的帮助!只是一个小问题,对于“model=>model.person.Id\u ProductPackageCategory”部分,VS显示了一个错误,即“无法将lambda表达式转换为类型'string',因为它不是委托类型”…请确保使用System.Data添加
,使用System.Data.Entity添加,使用System.Linq添加代码>我的错误,我忘记修改“DropDownList for”中的“DropDownList”,谢谢!再次感谢你的帮助!只是一个小问题,对于“model=>model.person.Id\u ProductPackageCategory”部分,VS显示了一个错误,即“无法将lambda表达式转换为类型'string',因为它不是委托类型”…我的错误,我忘了在“DropdownListFor”中修改“DropDownList”,谢谢!
public ActionResult Create()
{
ViewBag.Id_ProductPackageCategory = new SelectList(db.ProductPackageCategories, "Id_ProductPackageCategory", "Name");
return View();
}
@Html.DropDownListFor(model => model.person.Id_ProductPackageCategory, ViewBag.Id_ProductPackageCategory as SelectList, "--- Select Category ---", new { @class = "some_class" })