c# - 在数据模型类的属性中包含一些逻辑代码是否可以？

Question

我正在学习 MVC 3，但我没有发现有人在数据模型类的属性中使用某些逻辑代码。

他们做数据模型类如下(举例):

public class Customer
{
    public int CustomerId {get;set;}
    //other properties without any logic code.
}

是否可以在属性中包含如下逻辑代码？

public class Customer
{
    private int customerId;
    public int CustomerId {
       get{return customerId;}
       set
       {
         customerId=value;
         // some logic codes go here.
       }
    }
    //other properties go here.
}

---

编辑 1:

这是我的真实场景:

子表数据模型:

namespace MvcApplication1.Models
{
    public class Choice
    {
        public int ChoiceId { get; set; }
        public string Description { get; set; }
        public bool IsCorrect { get; set; }
        public QuizItem QuizItem { get; set; }
    }
}

父表数据模型:

namespace MvcApplication1.Models
{
    public class QuizItem
    {
        public int QuizItemId { get; set; }
        public string Question { get; set; }

        private IEnumerable<Choice> choices;
        public IEnumerable<Choice> Choices
        {
            get { return choices; }

            set
            {
                choices = value;
                foreach (var x in choices)
                    x.QuizItem = this;
            }
        }
    }
}

消费者:

namespace MvcApplication1.Controllers
{
    public class HomeController : Controller
    {
        public ActionResult Index()
        {


            var data = new List<QuizItem>{
                new QuizItem
                {
                    QuizItemId = 1,
                    Question = "What color is your hair?",
                    Choices = new Choice[]{
                        new Choice{ ChoiceId=1, Description="Black.", IsCorrect=true},
                        new Choice{ ChoiceId=2, Description="Red.", IsCorrect=false},
                        new Choice{ ChoiceId=3, Description="Yellow.", IsCorrect=false}
                    }
                },
                new QuizItem
                {
                    QuizItemId = 2,
                    Question = "What color is your noze?",
                    Choices = new Choice[]{
                        new Choice{ChoiceId=1, Description="Pink.", IsCorrect=false},
                        new Choice{ChoiceId=2, Description="Maroon.", IsCorrect=true},
                        new Choice{ChoiceId=3, Description="Navy Blue.", IsCorrect=false}
                    }
                }
            };


            return View(data);
        }

    }
}

Answer 1

这需要一个方法。两个原因:

• 我不推荐 Collections 的 setter
  • Property Usage Guidelines - 每次设置属性时都为集合中的每个项目设置属性是昂贵的，不应该在属性中。首选方法。
• setter 中的代码(在你的情况下)会导致足够的副作用，从而取消使用属性的资格
  • Setters for collection type properties - 在 StackOverflow 上讨论关于集合的 setter 。

我建议如下:

public class QuizItem
{
    public int QuizItemId { get; set; }
    public string Question { get; set; }

    private IEnumerable<Choice> choices;
    public IEnumerable<Choice> Choices
    {
        get { return choices; }
    }

    public void SetChoices(IEnumerable<Choice> choices)
    {
        foreach (var x in choices)
            x.QuizItem = this;

        this.choices = choices;                
    }
}