实体框架只读集合

问题描述

考虑一个域名，其中一个客户，公司，员工，等等等等，有一个物业的ContactInfo这反过来又包含了一组地址（ES），电话（ES），电子邮件（S），等等等等......

Consider a domain where a Customer, Company, Employee, etc, etc, have a ContactInfo property which in turn contains a set of Address(es), Phone(es), Email(s), etc, etc...

下面是我的缩写的ContactInfo：

Here is my abbreviated ContactInfo:

public class ContactInfo : Entity<int>
{
    public ContactInfo()
    {
        Addresses = new HashSet<Address>();
    }

    public virtual ISet<Address> Addresses { get ; private set; }

    public Address PrimaryAddress
    {
        get { return Addresses.FirstOrDefault(a => a.IsPrimary); }
    }

    public bool AddAddress(Address address)
    {
        // insure there is only one primary address in collection
        if (address.IsPrimary)
        {
            if (PrimaryAddress != null)
            {
                PrimaryAddress.IsPrimary = false;
            }
        }
        else
        {
            // make sure the only address in collection is primary
            if (!Addresses.Any())
            {
                address.IsPrimary = true;
            }
        }
        return Addresses.Add(address);
    }
}

一些注意事项（我不是100％肯定，如果这些是EF最佳实践）：

Some notes (I am not 100% sure if these are EF "best practices"):

• 地址（ES）的集合是虚拟的，允许延迟加载


• 在收集私人二传手禁止收集更换


• 集是的ISet ，以确保有每个触点没有重复的地址


• 使用 AddAddress 方法我能保证总是有至多1的地址是主要的....

• collection of Address(es) is virtual to allow for lazy loading
• private setter on collection prohibits collection replacement
• collection is an ISet to insure that there are no duplicate addresses per contact
• using AddAddress method I can insure that there is always and at most 1 address which is primary....

我想（如果可能的话），以prevent通过添加地址ContactInfo.Addresses.Add（）方法，并使用的给力ContactInfo.AddAddress（地址地址） ...

I would like (if possible) to prevent adding Addresses via ContactInfo.Addresses.Add() method and to force using of ContactInfo.AddAddress(Address address)...

我想通过 ReadOnlyCollection还露出的地址集，但将与实体框架（V5）？这项工作

I am thinking exposing the set of addresses via ReadOnlyCollection but will this work with Entity Framework (v5)?

我怎么会去吗？

推荐答案

的一种方法是使保护ICollection的财产，并创建了IEnumerable的一个新的属性，只是返回的ICollection属性的列表。

One way is to make the ICollection property protected and create a new property of IEnumerable that just returns the list of the ICollection property.

这样做的缺点是，你是不是能够通过的ContactInfo上的地址进行查询得到一样生活在这个城市的所有CONTACTINFO。

The downside with this is that you are not able to query on addresses through the ContactInfo like get all contactinfo that lives in this city.

这是不可能的：

from c in ContactInfos
where c.Addresses.Contains(x => x.City == "New York")
select c

code：

public class ContactInfo : Entity<int>
{
    public ContactInfo()
    {
        Addresses = new HashSet<Address>();
    }

    protected virtual ISet<Address> AddressesCollection { get ; private set; }

    public IEnumerable<Address> Addresses { get { return AddressesCollection; }}

    public Address PrimaryAddress
    {
        get { return Addresses.FirstOrDefault(a => a.IsPrimary); }
    }

    public bool AddAddress(Address address)
    {
        // insure there is only one primary address in collection
        if (address.IsPrimary)
        {
            if (PrimaryAddress != null)
            {
                PrimaryAddress.IsPrimary = false;
            }
        }
        else
        {
            // make sure the only address in collection is primary
            if (!Addresses.Any())
            {
                address.IsPrimary = true;
            }
        }
        return Addresses.Add(address);
    }
}

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