与实体框架“代码优先”的映射

我正在尝试使用实体框架“代码优先”来映射我的实体，但在映射复杂类型时遇到问题。这是我的简化示例：

域对象看起来像：

public class Customer
{
    public Address DeliveryAddress {get; set;}
}

public class Address
{
    public string StreetName {get; set;}
    public string StreetNumber {get; set;}
    public City City {get; set;}
}

public class City
{
    public int Id {get; set;}
    public string Name {get; set;}
}

和映射：

public class CustomerConfiguration : EntityConfiguration<Customer>
{
    public CustomerConfiguration()
    {
        this.HasKey(b => b.Id);
        this.Property(b => b.Id).IsIdentity();

        this.MapSingleType(x => new
        {
            Id = x.Id,
            DeliveryAddress_StreetName = x.DeliveryAddress.StreetName,
            DeliveryAddress_StreetNumber = x.DeliveryAddress.StreetNumber,
            DeliveryAddress_CityId = x.DeliveryAddress.City.Id, // this line causes an exception
        }).ToTable("Customer");
    }
}

public class AddressConfiguration : ComplexTypeConfiguration<Address>
{
    public AddressConfiguration()
    {           
        this.Property(b => b.StreetName).HasMaxLength(100).IsRequired().IsUnicode();
        this.Property(b => b.StreetNumber).HasMaxLength(6).IsRequired().IsUnicode();
}

public class CityConfiguration : EntityConfiguration<City>
{
    public CityConfiguration()
    {
        this.HasKey(b => b.Id);
        this.Property(b => b.Id).IsIdentity();
        this.Property(b => b.Name).IsRequired().HasMaxLength(200).IsUnicode();

        this.MapSingleType(x => new
        {
            Id = x.Id,
            Name = x.Name,
        }).ToTable("City");
    }
}

抛出的异常是：“字典中不存在给定的键。”

谁能帮我？

您正在尝试将站点实体类型添加到地址复杂类型。这是不可能的。 与实体一样，复杂类型由标量属性或其他复杂类型属性组成。由于复杂类型没有键，因此除了父对象之外，实体框架无法管理复杂类型对象。
看看复杂型文章 http://msdn.microsoft.com/en-us/library/bb738472.aspx了解更多信息。