当我在做一个 ASP.NET MVC 项目时，我看到了一个奇怪的 EF 行为，这让我延迟了（确切地说，我至少在一个月内仍然被这个问题困住......直到现在我才意识到我的 DDD 架构代码没有损坏，它是我所拥有的与 EF 相关的代码错误）。
我的网站有帖子。每个帖子都有一组属性 ( PostAttributeValue)，每个属性值都有一个相关的PostAttributeDefinition，其中包含有关它的数据 - 例如标题、验证规则、原始值（二进制序列化）、数据类型等。
这是我的帖子模型：
public class Post
{
#region Settings
/// <summary>
/// Maximum linked images
/// </summary>
public static int MaximumLinkedImages
{
get { return Properties.Settings.Default.MaximumPostsLinkedImages; }
}
/// <summary>
/// Maximum linked image size in MB
/// </summary>
public static int MaximumLinkedImageSize
{
get { return Properties.Settings.Default.MaximumPostLinkedImageSize; }
}
/// <summary>
/// Delay hours between posts bumping
/// </summary>
public static int BumpPostDelayHours
{
get { return Properties.Settings.Default.BumpPostDelayHours; }
}
#endregion
#region ctor
public Post()
{
this.Attributes = new List<PostAttributeValue>();
this.LinkedImages = new List<string>();
}
#endregion
/// <summary>
/// The parent category that this post was posted into
/// </summary>
[Required]
public virtual Category ParentCategory { get; set; }
/// <summary>
/// The post unique identifier
/// </summary>
[Key]
public Guid PostIdentifier { get; set; }
/// <summary>
/// The post title (e.g. "Great vila!")
/// </summary>
[Required]
public string Title { get; set; }
/// <summary>
/// The post title url alias (e.g. "great-vila")
/// </summary>
public string TitleUrlAlias { get; set; }
/// <summary>
/// Post extra notes and information written by the author
/// </summary>
[Required]
public string Description { get; set; }
/// <summary>
/// The post item city
/// </summary>
[Required]
public virtual City City { get; set; }
/// <summary>
/// The post item location
/// </summary>
public string Location { get; set; }
/// <summary>
/// Is the post was published and marketed by brokerage (Tivuuch)
/// </summary>
[Required]
public bool Brokerage { get; set; }
/// <summary>
/// Post custom attributes
/// </summary>
public virtual ICollection<PostAttributeValue> Attributes { get; set; }
/// <summary>
/// The post assigned price
/// </summary>
[Required]
public int RequestedPrice { get; set; }
/// <summary>
/// List of images linked with the post (includes only the name of the picture, a.k.a "foo.png", "bar.jpg" etc.)
/// </summary>
public virtual ICollection<string> LinkedImages { get; set; }
public string LinkedImagesSerialized
{
get
{
if (this.LinkedImages == null)
{
this.LinkedImages = new List<string>();
}
return string.Join(",", this.LinkedImages);
}
set
{
if (this.LinkedImages == null)
{
this.LinkedImages = new List<string>();
}
if (string.IsNullOrEmpty(value))
{
return;
}
this.LinkedImages = value.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries).ToList();
}
}
/// <summary>
/// Cached generated cached url using IShorterUrlService
/// </summary>
public string GeneratedShorterUrl { get; set; }
/// <summary>
/// Is this post marked as hot
/// </summary>
public bool IsHotPost { get; set; }
/// <summary>
/// The post publish status
/// </summary>
public PostPublishStatus PublishStatus { get; set; }
/// <summary>
/// The post author
/// </summary>
public virtual Account Author { get; set; }
/// <summary>
/// The author IP address (collected to determine different IPs)
/// </summary>
public string AuthorIPAddress { get; set; }
/// <summary>
/// The creation date of the post
/// </summary>
public DateTime CreationDate { get; set; }
/// <summary>
/// The last post modification date
/// </summary>
public DateTime LastUpdatedDate { get; set; }
/// <summary>
/// The date that the post was bumped at, used to sort the posts in category.
/// </summary>
public DateTime LastBumpDate { get; set; }
}
这是PostAttributeValue
public class PostAttributeValue { /// /// 属性值 id /// [Key] public int AttributeValueId { get; 放; }
/// <summary>
/// The value owner post
/// </summary>
public virtual Post OwnerPost { get; set; }
/// <summary>
/// The value attribute definition id
/// </summary>
//public int RelatedAttributeDefinitionId { get; set; }
/// <summary>
/// The value attribute definition
/// </summary>
public virtual PostAttributeDefinition Definition { get; set; }
/// <summary>
/// The stored raw value
/// </summary>
public byte[] RawValue { get; set; }
}
这是PostAttributeDefinition
public class PostAttributeDefinition { /// /// 过滤器名称 /// [Key] public int DefinitionId { get; 放; }
/// <summary>
/// The owner category
/// </summary>
[Required]
public virtual Category OwnerCategory { get; set; }
/// <summary>
/// The filter title
/// </summary>
[Required]
public string Title { get; set; }
/// <summary>
/// Metadata enum that provides extra data about the data type
/// </summary>
public PostAttributeTypeMetadata TypeMetadata { get; set; }
/// <summary>
/// Bitwise metadata that provides data about the object in display mode
/// </summary>
public PostAttributeDisplayModeMetadata DisplayModeMetadata { get; set; }
public PostAttributeEditorType EditorType { get; set; }
/// <summary>
/// The attribute raw default value
/// </summary>
[Required]
public byte[] RawDataValue { get; set; }
/// <summary>
/// The attribute raw associated validation attributes
/// </summary>
public byte[] RawValidationRules { get; set; }
/// <summary>
/// Is this field required
/// </summary>
public bool IsRequired { get; set; }
}
我的问题是，当我尝试添加新帖子时，我遇到了关系错误（来自 AssociationSet 的关系处于“已删除”状态），即
A relationship from the 'PostAttributeValue_Definition' AssociationSet is in the 'Deleted' state. Given multiplicity constraints, a corresponding 'PostAttributeValue_Definition_Source' must also in the 'Deleted' state.
现在，我发现问题在于，当我为 PostAttributeValue 分配一个定义时，它会自动变为已删除 - 即使我正在分配一个我现在从数据库中获取的定义。
我已经测试了上面的代码：
var db = ServiceLocator.SharedInstance.GetInstance<MyDbContext>();
List<PostAttributeValue> v = new List<PostAttributeValue>();
var entity = db.PostAttributesDefinitions.Where(d => d.DefinitionId==1).Include(d => d.OwnerCategory).First();
v.Add(new PostAttributeValue() { Definition = entity });
Post post = new Post()
{
Title = "foo",
Description = "bar",
City = new City { },
Brokerage = false,
Location = "",
RequestedPrice = 500,
ParentCategory = new Category() { },
AuthorIPAddress = "",
Attributes = v
};
db.Posts.Add(post);
var deletedValuesStore = ((System.Data.Entity.Infrastructure.IObjectContextAdapter)db)
.ObjectContext.ObjectStateManager.GetObjectStateEntries(System.Data.EntityState.Deleted);
并看到 deletedValuesStore 包含 1 项 - 定义。当我评论这条线时，商店里没有商品。
你有什么想法可以解决吗？谢谢你的时间！