我正在从
学习MVC中的实体框架https://www.youtube.com/watch?v=8f4P8U1a2TI
在索引视图中，它给出以下错误：
CS0121：以下方法或属性之间的调用不明确：'System.Web.Mvc.Html.DisplayNameExtensions.DisplayNameFor和
“System.Web.Mvc.Html.DisplayNameExtensions.DisplayNameFor，MvcApplication1.Models.Department＆GT;
索引视图：
@model IEnumerable<MvcApplication1.Models.Employee>
@{
ViewBag.Title = "Index";
}
<div style="font-family">
<h2>
Index</h2>
<p>
@Html.ActionLink("Create New", "Create")
</p>
</div>
<table border="1">
<tr>
<th> </th>
</tr>
@foreach (var item in Model)
{
<tr>
<td> @Html.DisplayNameFor(modelItem => item.Name) </td>
</tr>
}
</table>
员工控制员：
namespace MvcApplication1.Controllers
{
public class EmployeeController : Controller
{
private EmployeeContext1 db = new EmployeeContext1();
//
// GET: /Employee/
public ActionResult Index()
{
var employees = db.Employees.Include("Department");
return View(employees.ToList());
}
//
// GET: /Employee/Details/5
public ActionResult Details(int id = 0)
{
Employee employee = db.Employees.Single(e => e.Id == id);
if (employee == null)
{
return HttpNotFound();
}
return View(employee);
}
//
// GET: /Employee/Create
public ActionResult Create()
{
ViewBag.DepartmentId = new SelectList(db.Departments, "Id", "Name");
return View();
}
//
// POST: /Employee/Create
[HttpPost]
public ActionResult Create(Employee employee)
{
if (ModelState.IsValid)
{
db.Employees.AddObject(employee);
db.SaveChanges();
return RedirectToAction("Index");
}
ViewBag.DepartmentId = new SelectList(db.Departments, "Id", "Name", employee.DepartmentId);
return View(employee);
}
//
// GET: /Employee/Edit/5
public ActionResult Edit(int id = 0)
{
Employee employee = db.Employees.Single(e => e.Id == id);
if (employee == null)
{
return HttpNotFound();
}
ViewBag.DepartmentId = new SelectList(db.Departments, "Id", "Name", employee.DepartmentId);
return View(employee);
}
//
// POST: /Employee/Edit/5
[HttpPost]
public ActionResult Edit(Employee employee)
{
if (ModelState.IsValid)
{
db.Employees.Attach(employee);
db.ObjectStateManager.ChangeObjectState(employee, System.Data.EntityState.Modified);
db.SaveChanges();
return RedirectToAction("Index");
}
ViewBag.DepartmentId = new SelectList(db.Departments, "Id", "Name", employee.DepartmentId);
return View(employee);
}
//
// GET: /Employee/Delete/5
public ActionResult Delete(int id = 0)
{
Employee employee = db.Employees.Single(e => e.Id == id);
if (employee == null)
{
return HttpNotFound();
}
return View(employee);
}
//
// POST: /Employee/Delete/5
[HttpPost, ActionName("Delete")]
public ActionResult DeleteConfirmed(int id)
{
Employee employee = db.Employees.Single(e => e.Id == id);
db.Employees.DeleteObject(employee);
db.SaveChanges();
return RedirectToAction("Index");
}
protected override void Dispose(bool disposing)
{
db.Dispose();
base.Dispose(disposing);
}
}
}
AutoGenerated Model Class：
public partial class Employee : EntityObject
{
#region Factory Method
/// <summary>
/// Create a new Employee object.
/// </summary>
/// <param name="id">Initial value of the Id property.</param>
public static Employee CreateEmployee(global::System.Int32 id)
{
Employee employee = new Employee();
employee.Id = id;
return employee;
}
#endregion
#region Primitive Properties
/// <summary>
/// No Metadata Documentation available.
/// </summary>
[EdmScalarPropertyAttribute(EntityKeyProperty=true, IsNullable=false)]
[DataMemberAttribute()]
public global::System.Int32 Id
{
get
{
return _Id;
}
set
{
if (_Id != value)
{
OnIdChanging(value);
ReportPropertyChanging("Id");
_Id = StructuralObject.SetValidValue(value);
ReportPropertyChanged("Id");
OnIdChanged();
}
}
}
private global::System.Int32 _Id;
partial void OnIdChanging(global::System.Int32 value);
partial void OnIdChanged();
/// <summary>
/// No Metadata Documentation available.
/// </summary>
[EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=true)]
[DataMemberAttribute()]
public global::System.String Name
{
get
{
return _Name;
}
set
{
OnNameChanging(value);
ReportPropertyChanging("Name");
_Name = StructuralObject.SetValidValue(value, true);
ReportPropertyChanged("Name");
OnNameChanged();
}
}
private global::System.String _Name;
partial void OnNameChanging(global::System.String value);
partial void OnNameChanged();
/// <summary>
/// No Metadata Documentation available.
/// </summary>
[EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=true)]
[DataMemberAttribute()]
public global::System.String Gender
{
get
{
return _Gender;
}
set
{
OnGenderChanging(value);
ReportPropertyChanging("Gender");
_Gender = StructuralObject.SetValidValue(value, true);
ReportPropertyChanged("Gender");
OnGenderChanged();
}
}
private global::System.String _Gender;
partial void OnGenderChanging(global::System.String value);
partial void OnGenderChanged();
/// <summary>
/// No Metadata Documentation available.
/// </summary>
[EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=true)]
[DataMemberAttribute()]
public global::System.String City
{
get
{
return _City;
}
set
{
OnCityChanging(value);
ReportPropertyChanging("City");
_City = StructuralObject.SetValidValue(value, true);
ReportPropertyChanged("City");
OnCityChanged();
}
}
private global::System.String _City;
partial void OnCityChanging(global::System.String value);
partial void OnCityChanged();
/// <summary>
/// No Metadata Documentation available.
/// </summary>
[EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=true)]
[DataMemberAttribute()]
public Nullable<global::System.Int32> DepartmentId
{
get
{
return _DepartmentId;
}
set
{
OnDepartmentIdChanging(value);
ReportPropertyChanging("DepartmentId");
_DepartmentId = StructuralObject.SetValidValue(value);
ReportPropertyChanged("DepartmentId");
OnDepartmentIdChanged();
}
}
private Nullable<global::System.Int32> _DepartmentId;
partial void OnDepartmentIdChanging(Nullable<global::System.Int32> value);
partial void OnDepartmentIdChanged();
#endregion
#region Navigation Properties
/// <summary>
/// No Metadata Documentation available.
/// </summary>
[XmlIgnoreAttribute()]
[SoapIgnoreAttribute()]
[DataMemberAttribute()]
[EdmRelationshipNavigationPropertyAttribute("ComputerFirmModel", "FK__tblEmploy__Depar__4222D4EF", "tblDepartment")]
public Department Department
{
get
{
return ((IEntityWithRelationships)this).RelationshipManager.GetRelatedReference<Department>("ComputerFirmModel.FK__tblEmploy__Depar__4222D4EF", "tblDepartment").Value;
}
set
{
((IEntityWithRelationships)this).RelationshipManager.GetRelatedReference<Department>("ComputerFirmModel.FK__tblEmploy__Depar__4222D4EF", "tblDepartment").Value = value;
}
}
/// <summary>
/// No Metadata Documentation available.
/// </summary>
[BrowsableAttribute(false)]
[DataMemberAttribute()]
public EntityReference<Department> DepartmentReference
{
get
{
return ((IEntityWithRelationships)this).RelationshipManager.GetRelatedReference<Department>("ComputerFirmModel.FK__tblEmploy__Depar__4222D4EF", "tblDepartment");
}
set
{
if ((value != null))
{
((IEntityWithRelationships)this).RelationshipManager.InitializeRelatedReference<Department>("ComputerFirmModel.FK__tblEmploy__Depar__4222D4EF", "tblDepartment", value);
}
}
}
#endregion
}
...请建议
答案 0 :(得分：3)
该错误几乎可以告诉您问题究竟是什么。你有一个实现Html.DisplayNameFor的静态扩展类，而MVC有自己的实现相同的扩展类。您无法覆盖扩展方法，因此您需要使方法的名称唯一，或者只加载一个或另一个程序集。由于您无法不加载MVC，这意味着您需要将方法名称更改为Html.MyDisplayNameFor之类的其他名称。