在MVC中的ViewModel中使用Business Logic是否有意义？

Question

目前我正在使用Asp.Net MVC:存储库,工作单元模式,服务层和ViewModel.

在此项目中,每个View都链接到ViewModel类,控制器是瘦的,因此业务层驻留在服务层上.

我在Controller中创建ViewModel类的实例,并将其传递给视图

    public ActionResult Create()
    {
        EventCreateViewModel eventViewModel = new EventCreateViewModel();
        return View(eventViewModel);
    }

在一些ViewModel中,我用来调用服务层.

系统有效,但我想知道在ViewModel中添加对服务层的调用是否是一个好主意,或者更好的方法是将此操作仅留给Controller.

---

 public class EventCreateViewModel
    {

        public CandidateListViewModel CandidateList = new CandidateListViewModel();

        public EventCreateViewModel()
        {
            DateTimeStart = DateTime.UtcNow;    // Add a default value when a Date is not selected
        }
    }
}

---

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

using System.Web.Mvc;
using System.ComponentModel.DataAnnotations;

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Web;

    using XXX.Models;
    using XXX.Service;

        namespace XXX.ViewModels
        {
            public class CandidateListViewModel
            {
                // We are using the Service Layer
                private ICandidateBL serviceCandidate;

                // Property
                public IDictionary<string, string> Candidates = new Dictionary<string, string>();

                // An utility method that convert a list of Canddates from Enumerable to SortedDictionary
                // and save the result to an inner SortedDictionary for store
                public void ConvertSave(IEnumerable<Candidate> candidates)
                {
                    Candidates.Add("None", "0");    // Add option for no candidate
                    foreach (var candidate in candidates)
                        Candidates.Add(candidate.Nominative, candidate.CandidateId.ToString());
                }

                #region Costructors
                public CandidateListViewModel()
                {
                    serviceCandidate = new CandidateBL();
                    ConvertSave(serviceCandidate.GetCandidates());
                }

                // Dependency Injection enabled constructors
                public CandidateListViewModel(ICandidateBL serviceCandidate)
                {
                    this.serviceCandidate = serviceCandidate;
                }

                public CandidateListViewModel(IEnumerable<Candidate> candidates)
                {
                    serviceCandidate = new CandidateBL();
                    ConvertSave(candidates);
                }
                #endregion
            }
        }

Answer 1

控制器是应该控制的组件,可以这么说.ViewModel应该只是一个数据容器,仅此而已.

记住单一责任原则.一旦开始分配逻辑,记住和理解所有运动部件将变得越来越困难.