entity-framework-4.1 - EF 导航属性和映射问题

Question

一开始我想提一下，我已经为这个问题奋斗了几天，并尝试了很多或多或少与这个问题相关的答案。但是我无法解决它。

我有两个类代表数据库中的表。这些是遗留应用程序使用的现有表，我无法更改它们。

消息可以有多个消息接收者。

环境:MVC3、EF4.1

类是:

public class Message
{
    [ForeignKey("MessageReciepients")]
    public virtual int MessageID { get; set; }
    public string Title { get; set; }
    public string Content { get; set; }
    public DateTime Recieved { get; set; }
    [ForeignKey("User")]
    public int AuthorUserID { get; set; }

    //P\\ Navigation properties
    public virtual IList<MessageRecipient> MessageReciepients { get; set; }
    public virtual User User { get; set; }
}

public class MessageRecipient
{
    //[Key]
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int MessageID { get; set; }
    public int UserID { get; set; }
    public bool Read { get; set; }
    public bool Important { get; set; }
    public bool Deleted { get; set; }
    public bool Destroyed { get; set; }

    //P\\ Navigation Properties
    public virtual User User { get; set; }
}

我的错误是:

The foreign key component 'MessageID' is not a declared property on type 'MessageRecipient'. Verify that it has not been explicitly excluded from the model and that it is a valid primitive property.

如何正确映射这些类、关系来加载消息的接收者？

我可以补充一点，导航属性 User 可以正确地处理消息并正确加载用户的数据。

我对 .NET 不是很熟悉，但我是边做边学的。我尝试了一些 EF API 配置来映射这些我尝试对它发誓、诅咒它，同时几乎要哭泣和祈祷。不开心!!

非常感谢您的帮助。

Answer 1

原来问题出在我需要使用的复合键上，这一切都可以通过一些属性来解决:

现在是这样的:

public class Message
{
    public int MessageID { get; set; }
    public string Title { get; set; }
    public string Content { get; set; }
    public DateTime Recieved { get; set; }

    [ForeignKey("User")]
    public int AuthorUserID { get; set; }

    //P\\ Navigation properties
    public virtual ICollection<MessageRecipient> MessageRecipients { get; set; }
    public virtual User User { get; set; }
}

public class MessageRecipient
{
    [Key, Column(Order=0), ForeignKey("User")]
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int UserID { get; set; }

    [Key, Column(Order = 1)]
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int MessageID { get; set; }

    public bool Read { get; set; }
    public bool Important { get; set; }
    public bool Deleted { get; set; }
    public bool Destroyed { get; set; }

    //P\\ Navigation Properties
    public virtual User User { get; set; }
}