Question

我在定义这两个类时遇到问题：

public class Article
{
    public Article(long ID, string Name, ArticleFamily Family)
    {
        //...Initializer...
    }
    public ArticleFamily Family { get; set; }
    //Other props...
}

public class ArticleFamily
{
    public ArticleFamily(int ID, string Description)
    {
        //...Initializer...
    }
    public int ID { get; private set; }
    public string Description { get; set; }
}

我有文章的集合，每个人都属于一个家庭现在，鉴于我有一个 ArticleFamily 对象，我应该能够更改其描述，并最终将其持久保存到DataBase。（为简单起见，我省略了那部分）但我不应该这样做：

Article art = SomeMethodReturningArticle();
art.Family.Description = "SomeOtherValue";

我应该能够完全更改文章的系列，将其替换为新的 ArticleFamily 对象，但我不能仅仅更改说明。
我应该使用这样的只读属性创建 ArticleFamily 类的副本：

public class ArticleFamilyReadonly
{
    ArticleFamily _family;
    public ArticleFamilyReadonly(ArticleFamily Family)
    {
        _family = Family;
    }
    public int ID { get { return _family.ID; } }
    //etc...
}

我怎样才能以干净的方式做到这一点？

Answer 1

这是我在LinqPad中一起扔的东西：

void Main()
{
    var art = new Article(1,"2", new ArticleFamily(1, "Test"));
    art.Family.Description = "What?"; // Won't work

    var fam = art.Family as ArticleFamily;
    fam.Description = "This works"; // This works...

}

public class Article
{
    public Article(long ID, string Name, IArticleFamily Family)
    {
        //...Initializer...
    }
    public IArticleFamily Family { get; set; }
    //Other props...
}

public class ArticleFamily : IArticleFamily
{
    public ArticleFamily(int ID, string Description)
    {
        //...Initializer...
    }
    public int ID { get; private set; }
    public string Description { get; set; }
}

public interface IArticleFamily
{
    int ID { get; }
    string Description { get;}
}

除非转换为ArticleFamily对象，否则无法直接从Article对象进行编辑。

只读嵌套对象属性

1 个答案: