Entityframework：启用延时加载的主意事项（只为强化记忆）

Check List

• 无参的、高于私有访问级别的构造方法（经常忘记）。
• 非封闭的类（默认的非封闭的）。
• DbContext 配置要开启（默认是开启的）。

因为我喜欢将类型设置为封闭的，提供有参数的构造方法，尽可能的低的访问级别，而这些原则和延时加载的原则刚好相反，因此写下来强化一下记忆。

示例

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;

 using Happy.Archetype;
 using Happy.Domain;
 using Happy.Cms.Domain.Shares;

 namespace Happy.Cms.Domain.Articles
 {
     [DomainModel, Moment]
     public class Article : AggregateRoot<Guid>
     {
         private ICollection<AssignedTag> _assignedTags = new List<AssignedTag>();

         protected Article()
         {
         }

         public Article(Guid id)
             : base(id)
         {
             this.SettingInfo = new SettingInfo();
             this.ImageInfo = new ImageInfo();
             this.SeoInfo = new SeoInfo();
         }

         public string Title { get; set; }

         public Guid CategoryId { get; set; }

         public string Author { get; set; }

         public ImageInfo ImageInfo { get; private set; }

         public SettingInfo SettingInfo { get; private set; }

         public virtual ICollection<AssignedTag> AssignedTags
         {
             get { return _assignedTags; }
             protected set { _assignedTags = value; }
         }

         public string Content { get; set; }

         public SeoInfo SeoInfo { get; private set; }

         public void AssignTags(IEnumerable<Guid> tagIds)
         {
             tagIds = tagIds ?? Enumerable.Empty<Guid>();

             var oldAssignedTagIds = this.AssignedTags.Select(x => x.TagId).ToList();
             var addedTagIds = tagIds.Except(oldAssignedTagIds);
             var removedTagIds = oldAssignedTagIds.Except(tagIds);

             foreach (var addedTagId in addedTagIds)
             {
                 this.AssignedTags.Add(new AssignedTag(Guid.NewGuid(), addedTagId));
             }

             foreach (var removedTagId in removedTagIds)
             {
                 this.AssignedTags.Remove(this.AssignedTags.First(x => x.TagId == removedTagId));
             }
         }
     }
 }