c# - 尝试使用 EF 更新实体并使用 WCF 发送它 - 属性在更新场景中导致异常

Question

我正在尝试使用 WCF 发送一个对象。使用 EF 从数据库中检索对象。

这是我得到的异常:

这只发生在更新场景中。插入效果完美。
跟踪错误，我发现问题出在我最近添加的一个集合(称为 Travelers)上。

以下是当我尝试在运行时观察它的值时发生的情况，在更新之后，在 WCF 发送更新的实体之前:

这是有问题的类的属性声明(我尝试取消对 DataMember 属性的注释，但没有成功):

[DataContract]
public class Travel : InsuredObject, ISaleEntity, ICloneable
{    
    //[DataMember]
    public virtual ICollection<Traveler> Travelers { get; set; } 
    ...  

我读过 this.Configuration.ProxyCreationEnabled = false; 和/或 this.Configuration.LazyLoadingEnabled = false; 可能会修复它，但我不能出于我以外的原因更改它们，甚至当我尝试与它们一起玩时 - 我还有一些其他异常(exception)......

附加代码:
更新方法:

public virtual TEntity CreateAndUpdate(int saleId, TEntity entity) {
    var context = ((IObjectContextAdapter)this.Context).ObjectContext;

    var objBaseSet = context.CreateObjectSet<TBase>();

    var entityBaseKey = context.CreateEntityKey(objBaseSet.EntitySet.Name, entity);
    Object foundBaseEntity;
    var baseExists = context.TryGetObjectByKey(entityBaseKey, out foundBaseEntity);

    entity.Id = saleId;

    if (!baseExists) {
        this.GetDbSet<TEntity>().Add(entity); 
    }

    this.objectContext.SaveChanges();

    return entity;
}  

在更新之前检索包含的对象:

public virtual IQueryable<TEntity> GetAll(Expression<Func<TEntity, bool>> where, bool brutalRefresh = false) {

    IQueryable<TEntity> retObj = this.GetDbSet<TEntity>();
    if (where != null) {
        retObj = retObj.Where(where);
    }

    if (brutalRefresh) {
        var context = ((IObjectContextAdapter)this.Context).ObjectContext;
        context.Refresh(RefreshMode.StoreWins, retObj);
    }

    return retObj;
}

...所有这些代码都是与其他项目的通用代码，它们发送和接收与我相同的实体，它只是我添加的 Travel 实体，这给我带来了问题，所以解决方案我正在寻找应该包含 0 个公共(public)代码更改..

Traveler 类(完全):

 [DataContract]
    public class Traveler : ISaleEntity, ICloneable
    {
        [DataMember]
        public int Id { get; set; }

        [DataMember]
        public string FirstName { get; set; }

        [DataMember]
        public string LastName { get; set; }

        [DataMember]
        public string IDNumber { get; set; }

        [DataMember]
        public DateTime? BirthDate { get; set; }

        [DataMember]
        public virtual ICollection<SelectedCoverage> SelectedCoverages { get; set; }

        [NotMapped]
        public List<MedicalQuestionnaireAnswer> MedicalQuestionnaireAnswers
        {
            get
            {
                if (string.IsNullOrWhiteSpace(DBMedicalQuestionnaireAnswers))
                    return new List<MedicalQuestionnaireAnswer>();

                return DBMedicalQuestionnaireAnswers.Split(',')
                    .Select(c => (MedicalQuestionnaireAnswer)int.Parse(c)).ToList();
            }
            set { DBMedicalQuestionnaireAnswers = string.Join(",", value.Select(m => (int)m)); }
        }

        [NotMapped]
        public Genders Gender
        {
            get { return (Genders)DBGender; }
            set { DBGender = (int)value; }
        }

        /// <summary>
        /// NOTE! Do not use this property directly! use MedicalQuestionnaireAnswers instead
        /// </summary>
        [DataMember]
        public string DBMedicalQuestionnaireAnswers { get; set; }

        /// <summary>
        /// NOTE! Do not use this property directly! use Gender instead
        /// </summary>
        [DataMember]
        public int DBGender { get; set; }

        public object Clone()
        {
            Traveler traveler = new Traveler();
            traveler.FirstName = this.FirstName;
            traveler.LastName = this.LastName;
            traveler.IDNumber = this.IDNumber;
            traveler.BirthDate = this.BirthDate;
            traveler.DBMedicalQuestionnaireAnswers = this.DBMedicalQuestionnaireAnswers;
            traveler.Gender = this.Gender;
            if (this.SelectedCoverages != null)
            {
                traveler.SelectedCoverages = this.SelectedCoverages.Select(sc => (SelectedCoverage)sc.Clone()).ToList();
            }

            return traveler;
        }
    }

    public static class TravelerExtension
    {

        /// <summary>
        /// copy all the property except from the id and src defualt values
        /// </summary>
        /// <param name="dbTraveler"></param>
        /// <param name="src"></param>
        public static void CopyTravelerProperties(this Traveler target, Traveler src)
        {
            target.FirstName = src.FirstName;
            target.LastName = src.LastName;
            target.IDNumber = src.IDNumber;
            target.BirthDate = src.BirthDate;
            target.DBMedicalQuestionnaireAnswers = src.DBMedicalQuestionnaireAnswers;
            target.DBGender = src.DBGender;
            target.SelectedCoverages.CopySelectedCoveragesProperties(src.SelectedCoverages);
        }
    }

    public static class TravelersExtension
    {

        /// <summary>
        /// copy all the property except from the id and src defualt values
        /// </summary>
        /// <param name="dbTravelers"></param>
        /// <param name="src"></param>
        public static void CopyTravelersProperties(this ICollection<Traveler> target, ICollection<Traveler> src)
        {

            List<int> allTravelersIdsSrc = src.Select(t => t.Id).ToList();

            // remove ids exist target and not in src 
            target.ToList().RemoveAll(t => allTravelersIdsSrc.Contains(t.Id));


            target = target ?? new List<Traveler>();
            foreach (Traveler srcTraveler in src)
            {
                var targetTraveler = target.FirstOrDefault(targetTrv => srcTraveler.Id != 0 && targetTrv.Id == srcTraveler.Id);
                // if not exist traveler with target traveler id in db
                if (targetTraveler == null)
                {
                    // add srcTraveler to target
                    target.Add(srcTraveler);
                }
                else
                {
                    targetTraveler.CopyTravelerProperties(srcTraveler);
                }

            }
        }
    }

更多信息:
如果在尝试获取即时窗口中的值之前调用 ToList()，则不会发生即时窗口异常。问题本身仍然存在。

试图评论 [DataMember] 属性:

public virtual ICollection<SelectedCoverage> SelectedCoverages { get; set; }

在 Traveler 类中没有影响。

异常:

更多信息 2:

只有 1 个实体导致异常:

public class Quote : ISaleEntity, ICloneable {      
    ...
        [DataMember]
        public virtual Travel Travel { get; set; } 
    ...   

当我将上面的 [DataMember] 更改为 [IgnoreDataMember] - 没有异常(exception)。

我把这个类的所有属性设置为[IgnoreDataMember]

[DataContract]
    public class Travel : InsuredObject, ISaleEntity, ICloneable
    {
         [IgnoreDataMember]
        //[DataMember]
        public bool? IsFromIsrael { get; set; }

        [IgnoreDataMember]
        //[DataMember]
        public virtual ICollection<Traveler> Travelers { get; set; }

        [IgnoreDataMember]
        public virtual Quote Quote { get; set; }

          [IgnoreDataMember]
        //[DataMember]
        [NotMapped]
        public List<int> DestinationsCodes
        {
            get
            {
                if (string.IsNullOrWhiteSpace(DBDestinationsCodes))
                    return new List<int>();

                return DBDestinationsCodes.Split(',').Select(c => int.Parse(c)).ToList();
            }

            set { DBDestinationsCodes = string.Join(",", value); }
        }

        /// <summary>
        /// NOTE! Do not use this property directly! use DestinationsCodes instead
        /// </summary>
             [IgnoreDataMember]
        //[DataMember]
        public string DBDestinationsCodes { get; set; }
        ...  

但是异常还是出现了。可能是因为这个类继承的类:

[DataContract]
    [KnownType(typeof(Vehicle))]
    [KnownType(typeof(Apartment))]
    [KnownType(typeof(Travel))]
    public class InsuredObject : ISaleEntity, ICloneable {
        [Key]
        [DataMember]
        public int Id { get; set; }

        [DataMember]
        public int? OwnerTypeId { get; set; }


        //navigation property

        [DataMember]
        public bool? HasShiabud { get; set; }

        [DataMember]
        [IgnoreDataMember]
        public virtual Shiabud Shiabud { get; set; }

        //[NotMapped]
        //public virtual Proposal Proposal { get; set; }

        //[DataMember]
        [IgnoreDataMember]
        public virtual ICollection<Coverage> Coverages { get; set; }  
        ...

那么我如何通过 WCF 发送这个实体呢？

Answer 1

通过使您的属性成为虚拟属性，您所做的就是延迟加载。

您可以改为将属性放入 ICollection 中，然后进行预先加载。