EntityReference.load entityReference.isloaded를 확인합니까?

Question

안녕 나는 궁금했다 EntityReference.Load 방법이 포함됩니다

If Not ref.IsLoaded Then ref.Load()

내 질문은 기본적으로 :

Dim person = Context.Persons.FirstOrDefault
person.AddressReference.Load()
person.AddressReference.Load() 'Does it do anything?

Answer 1

다시로드됩니다. 프로파일 러로 이것을 확인했으며 두 쿼리를 보여주었습니다. 기본 병합 옵션은 mergeoption입니다. 리플렉터의 코드 :

public override void Load(MergeOption mergeOption)
{
    base.CheckOwnerNull();
    ObjectQuery<TEntity> query = base.ValidateLoad<TEntity>(mergeOption, "EntityReference");
    base._suppressEvents = true;
    try
    {
        List<TEntity> collection = new List<TEntity>(RelatedEnd.GetResults<TEntity>(query));
        if (collection.Count > 1)
        {
            throw EntityUtil.MoreThanExpectedRelatedEntitiesFound();
        }
        if (collection.Count == 0)
        {
            if (base.ToEndMember.RelationshipMultiplicity == RelationshipMultiplicity.One)
            {
                throw EntityUtil.LessThanExpectedRelatedEntitiesFound();
            }
            if ((mergeOption == MergeOption.OverwriteChanges) || (mergeOption == MergeOption.PreserveChanges))
            {
                EntityKey entityKey = ObjectStateManager.FindKeyOnEntityWithRelationships(base.Owner);
                EntityUtil.CheckEntityKeyNull(entityKey);
                ObjectStateManager.RemoveRelationships(base.ObjectContext, mergeOption, (AssociationSet) base.RelationshipSet, entityKey, (AssociationEndMember) base.FromEndProperty);
            }
            base._isLoaded = true;
        }
        else
        {
            base.Merge<TEntity>(collection, mergeOption, true);
        }
    }
    finally
    {
        base._suppressEvents = false;
    }
    this.OnAssociationChanged(CollectionChangeAction.Refresh, null);
}

Answer 2

허용 된 답변을 찾는 다른 사람을 참조하기 위해, 여기에 현재 프로젝트를 위해 내가 만든 확장 방법이 있습니다.

using System.Data.Objects.DataClasses;

namespace ProjectName
{
    public static class EntityFrameworkExtensions
    {
        public static void EnsureLoaded<TEntity>(this EntityReference<TEntity> reference)
            where TEntity : class, IEntityWithRelationships
        {
            if (!reference.IsLoaded)
                reference.Load();
        }
    }
}

그리고 사용 :

Patient patient = // get patient

patient.ClinicReference.EnsureLoaded();
patient.Clinic.DoStuff();