ForeignKeyAttribute on属性无效

Question

我已经阅读过如何在MVC3中使用Code First Entity Framework(4.1)声明外键关系？但我无法接到我的号召,不会产生任何结果.它有以下错误:

类型为"MyBlog.Tbl_Footer_Item"的属性"Footer_Item_Header_ID"上的ForeignKeyAttribute无效.在依赖类型"MyBlog.Tbl_Footer_Item"上找不到导航属性"Tbl_Footer_Header".Name值应该是有效的导航属性名称.

在这一行:

Dim footerNavElements = db.Tbl_Footer_Headers.Where(Function(i) i.Footer_Header_Order = 1).Single.Items

这是我的父模型:

Imports System.Data.Entity
Imports System.ComponentModel.DataAnnotations

Public Class Tbl_Footer_Header

    <Key()> Public Property Footer_Header_ID() As Integer
    Public Property Footer_Header_Content() As String
    Public Property Footer_Header_Order() As Integer

    Public Overridable Property Items As ICollection(Of Tbl_Footer_Item)

End Class

Public Class FooterHeaderDbContext
    Inherits DbContext

    Public Property Tbl_Footer_Headers As DbSet(Of Tbl_Footer_Header)

End Class

这是我的孩子模特:

Imports System.Data.Entity
Imports System.ComponentModel.DataAnnotations

Public Class Tbl_Footer_Item

    <Key()> Public Property Footer_Item_ID() As Integer
    <ForeignKey("Tbl_Footer_Header")>
    Public Property Footer_Item_Header_ID() As Integer
    Public Property Footer_Item_Content() As String
    Public Property Footer_Item_Link() As String
    Public Property Footer_Header_Order() As Integer

    Public Overridable Property Header As Tbl_Footer_Header

End Class

Public Class FooterItemDbContext
    Inherits DbContext

    Public Property Tbl_Footer_Items As DbSet(Of Tbl_Footer_Item)
    Public Property Tbl_Footer_Headers As DbSet(Of Tbl_Footer_Header)

End Class

我该怎么做才能使操作产生没有错误的结果？谢谢.

Answer 1

您的外键是注释应该是属性的名称,而不是类型.

您的导航属性是标题:

Public Overridable Property Header As Tbl_Footer_Header

所以你的注释应该引用属性.将其更改为:

<ForeignKey("Header")>
Public Property Footer_Item_Header_ID() As Integer