Agregar hijo al registro principal existente en el marco de la entidad

Question

Mi relación entre el padre y el hijo es que están conectados por un borde. Es similar a una estructura de gráfico dirigida.

DAL:

public void SaveResource(Resource resource) 
    { 
     context.AddToResources(resource); //Should also add children. 
     context.SaveChanges(); 
    } 

    public Resource GetResource(int resourceId) 
    { 
     var resource = (from r in context.Resources 
         .Include("ToEdges").Include("FromEdges") 
         where r.ResourceId == resourceId 
         select r).SingleOrDefault(); 

     return resource; 
    } 

Servicio:

public void AddChildResource(int parentResourceId, Resource childResource) 
    { 
     Resource parentResource = repository.GetResource(parentResourceId); 

     ResourceEdge inEdge = new ResourceEdge(); 
     inEdge.ToResource = childResource; 

     parentResource.ToEdges.Add(inEdge); 

     repository.SaveResource(parentResource); 
    } 

de error: Un objeto con la misma clave ya existe en la ObjectStateManager. El objeto existente está en el estado Sin cambios. Un objeto solo se puede agregar al ObjectStateManager nuevamente si está en el estado agregado.

Image:

alt text http://img100.imageshack.us/img100/374/entity.png

Me han dicho que esto es la secuencia en la presentación de un niño a un padre ya existente:

Get padres -> Adjuntar hijo a padre -> Solicitud de los padres .

Esa es la secuencia que utilicé. El código anterior se extrae de una aplicación ASP.NET MVC 2 utilizando el patrón de repositorio.

archivo EDMX:

<?xml version="1.0" encoding="utf-8"?> 
    <edmx:Edmx Version="2.0" xmlns:edmx="http://schemas.microsoft.com/ado/2008/10/edmx"> 
     <!-- EF Runtime content --> 
     <edmx:Runtime> 
     <!-- SSDL content --> 
     <edmx:StorageModels> 
      <Schema Namespace="XDbModel.Store" Alias="Self" Provider="System.Data.SqlClient" ProviderManifestToken="2008" xmlns:store="http://schemas.microsoft.com/ado/2007/12/edm/EntityStoreSchemaGenerator" xmlns="http://schemas.microsoft.com/ado/2009/02/edm/ssdl"> 
      <EntityContainer Name="XDbModelStoreContainer"> 
       <EntitySet Name="Bundles" EntityType="XDbModel.Store.Bundles" store:Type="Tables" Schema="dbo" /> 
       <EntitySet Name="CellProviders" EntityType="XDbModel.Store.CellProviders" store:Type="Tables" Schema="dbo" /> 
       <EntitySet Name="Comments" EntityType="XDbModel.Store.Comments" store:Type="Tables" Schema="dbo" /> 
       <EntitySet Name="LocationPoints" EntityType="XDbModel.Store.LocationPoints" store:Type="Tables" Schema="dbo" /> 
       <EntitySet Name="Locations" EntityType="XDbModel.Store.Locations" store:Type="Tables" Schema="dbo" /> 
       <EntitySet Name="Offers" EntityType="XDbModel.Store.Offers" store:Type="Tables" Schema="dbo" /> 
       <EntitySet Name="PostBundleJunction" EntityType="XDbModel.Store.PostBundleJunction" store:Type="Tables" Schema="dbo" /> 
       <EntitySet Name="PostMedia" EntityType="XDbModel.Store.PostMedia" store:Type="Tables" Schema="dbo" /> 
       <EntitySet Name="Posts" EntityType="XDbModel.Store.Posts" store:Type="Tables" Schema="dbo" /> 
       <EntitySet Name="ResourceEdges" EntityType="XDbModel.Store.ResourceEdges" store:Type="Tables" Schema="dbo" /> 
       <EntitySet Name="ResourceNames" EntityType="XDbModel.Store.ResourceNames" store:Type="Tables" Schema="dbo" /> 
       <EntitySet Name="Resources" EntityType="XDbModel.Store.Resources" store:Type="Tables" Schema="dbo" /> 
       <EntitySet Name="sysdiagrams" EntityType="XDbModel.Store.sysdiagrams" store:Type="Tables" Schema="dbo" /> 
       <EntitySet Name="Users" EntityType="XDbModel.Store.Users" store:Type="Tables" Schema="dbo" /> 
       <EntitySet Name="Votes" EntityType="XDbModel.Store.Votes" store:Type="Tables" Schema="dbo" /> 
       <AssociationSet Name="FK_Comments_Offers" Association="XDbModel.Store.FK_Comments_Offers"> 
       <End Role="Offers" EntitySet="Offers" /> 
       <End Role="Comments" EntitySet="Comments" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_Comments_Users" Association="XDbModel.Store.FK_Comments_Users"> 
       <End Role="Users" EntitySet="Users" /> 
       <End Role="Comments" EntitySet="Comments" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_LocationPoints_Locations" Association="XDbModel.Store.FK_LocationPoints_Locations"> 
       <End Role="Locations" EntitySet="Locations" /> 
       <End Role="LocationPoints" EntitySet="LocationPoints" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_PostBundleJunction_Bundles" Association="XDbModel.Store.FK_PostBundleJunction_Bundles"> 
       <End Role="Bundles" EntitySet="Bundles" /> 
       <End Role="PostBundleJunction" EntitySet="PostBundleJunction" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_PostBundleJunction_Posts" Association="XDbModel.Store.FK_PostBundleJunction_Posts"> 
       <End Role="Posts" EntitySet="Posts" /> 
       <End Role="PostBundleJunction" EntitySet="PostBundleJunction" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_Posts_Locations" Association="XDbModel.Store.FK_Posts_Locations"> 
       <End Role="Locations" EntitySet="Locations" /> 
       <End Role="Posts" EntitySet="Posts" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_Posts_ResourceNames" Association="XDbModel.Store.FK_Posts_ResourceNames"> 
       <End Role="ResourceNames" EntitySet="ResourceNames" /> 
       <End Role="Posts" EntitySet="Posts" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_Posts_Users" Association="XDbModel.Store.FK_Posts_Users"> 
       <End Role="Users" EntitySet="Users" /> 
       <End Role="Posts" EntitySet="Posts" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_ResourceEdges_Resources" Association="XDbModel.Store.FK_ResourceEdges_Resources"> 
       <End Role="Resources" EntitySet="Resources" /> 
       <End Role="ResourceEdges" EntitySet="ResourceEdges" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_ResourceEdges_Resources1" Association="XDbModel.Store.FK_ResourceEdges_Resources1"> 
       <End Role="Resources" EntitySet="Resources" /> 
       <End Role="ResourceEdges" EntitySet="ResourceEdges" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_ResourceNames_Resources" Association="XDbModel.Store.FK_ResourceNames_Resources"> 
       <End Role="Resources" EntitySet="Resources" /> 
       <End Role="ResourceNames" EntitySet="ResourceNames" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_Users_Locations" Association="XDbModel.Store.FK_Users_Locations"> 
       <End Role="Locations" EntitySet="Locations" /> 
       <End Role="Users" EntitySet="Users" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_Votes_Posts" Association="XDbModel.Store.FK_Votes_Posts"> 
       <End Role="Posts" EntitySet="Posts" /> 
       <End Role="Votes" EntitySet="Votes" /> 
       </AssociationSet> 
      </EntityContainer> 
      <EntityType Name="Bundles"> 
       <Key> 
       <PropertyRef Name="BundleId" /> 
       </Key> 
       <Property Name="BundleId" Type="int" Nullable="false" /> 
      </EntityType> 
      <EntityType Name="CellProviders"> 
       <Key> 
       <PropertyRef Name="CellProviderID" /> 
       </Key> 
       <Property Name="CellProviderID" Type="uniqueidentifier" Nullable="false" /> 
      </EntityType> 
      <EntityType Name="Comments"> 
       <Key> 
       <PropertyRef Name="CommentID" /> 
       </Key> 
       <Property Name="CommentID" Type="uniqueidentifier" Nullable="false" /> 
       <Property Name="ParentPostID" Type="uniqueidentifier" /> 
       <Property Name="OfferPostID" Type="uniqueidentifier" /> 
       <Property Name="UserID" Type="uniqueidentifier" Nullable="false" /> 
      </EntityType> 
      <EntityType Name="LocationPoints"> 
       <Key> 
       <PropertyRef Name="LocationPointId" /> 
       </Key> 
       <Property Name="LocationPointId" Type="int" Nullable="false" StoreGeneratedPattern="Identity" /> 
       <Property Name="Latitude" Type="float" Nullable="false" /> 
       <Property Name="Longitude" Type="float" Nullable="false" /> 
       <Property Name="Altitude" Type="float" Nullable="false" /> 
       <Property Name="Count" Type="int" Nullable="false" /> 
       <Property Name="LocationId" Type="int" Nullable="false" /> 
      </EntityType> 
      <EntityType Name="Locations"> 
       <Key> 
       <PropertyRef Name="LocationId" /> 
       </Key> 
       <Property Name="LocationId" Type="int" Nullable="false" StoreGeneratedPattern="Identity" /> 
       <Property Name="Address1" Type="nvarchar" Nullable="false" MaxLength="200" /> 
       <Property Name="Address2" Type="nvarchar" MaxLength="200" /> 
       <Property Name="Address3" Type="nvarchar" MaxLength="200" /> 
       <Property Name="State" Type="nvarchar" Nullable="false" MaxLength="200" /> 
       <Property Name="Country" Type="nvarchar" Nullable="false" MaxLength="200" /> 
      </EntityType> 
      <EntityType Name="Offers"> 
       <Key> 
       <PropertyRef Name="OfferID" /> 
       </Key> 
       <Property Name="OfferID" Type="uniqueidentifier" Nullable="false" /> 
       <Property Name="NeedOffer" Type="uniqueidentifier" Nullable="false" /> 
       <Property Name="ProvisionOffer" Type="uniqueidentifier" Nullable="false" /> 
      </EntityType> 
      <EntityType Name="PostBundleJunction"> 
       <Key> 
       <PropertyRef Name="BundleId" /> 
       <PropertyRef Name="PostId" /> 
       </Key> 
       <Property Name="BundleId" Type="int" Nullable="false" /> 
       <Property Name="PostId" Type="int" Nullable="false" /> 
      </EntityType> 
      <EntityType Name="PostMedia"> 
       <Key> 
       <PropertyRef Name="MediaId" /> 
       </Key> 
       <Property Name="MediaId" Type="int" Nullable="false" StoreGeneratedPattern="Identity" /> 
       <Property Name="MediaExt" Type="nvarchar" Nullable="false" MaxLength="5" /> 
       <Property Name="PostId" Type="int" Nullable="false" /> 
       <Property Name="SynthId" Type="uniqueidentifier" /> 
      </EntityType> 
      <EntityType Name="Posts"> 
       <Key> 
       <PropertyRef Name="PostId" /> 
       </Key> 
       <Property Name="PostId" Type="int" Nullable="false" StoreGeneratedPattern="Identity" /> 
       <Property Name="PosterID" Type="uniqueidentifier" Nullable="false" /> 
       <Property Name="BundleId" Type="int" Nullable="false" /> 
       <Property Name="LocationId" Type="int" Nullable="false" /> 
       <Property Name="Tags" Type="uniqueidentifier" /> 
       <Property Name="Quanitity" Type="int" Nullable="false" /> 
       <Property Name="Description" Type="text" Nullable="false" /> 
       <Property Name="ResourceNameId" Type="int" Nullable="false" /> 
       <Property Name="Date" Type="datetime" Nullable="false" /> 
      </EntityType> 
      <EntityType Name="ResourceEdges"> 
       <Key> 
       <PropertyRef Name="EdgeId" /> 
       </Key> 
       <Property Name="Rank" Type="int" Nullable="false" /> 
       <Property Name="EdgeId" Type="int" Nullable="false" StoreGeneratedPattern="Identity" /> 
       <Property Name="ToResourceId" Type="int" Nullable="false" /> 
       <Property Name="FromResourrceId" Type="int" Nullable="false" /> 
      </EntityType> 
      <EntityType Name="ResourceNames"> 
       <Key> 
       <PropertyRef Name="ResourceNameId" /> 
       </Key> 
       <Property Name="ResourceNameId" Type="int" Nullable="false" StoreGeneratedPattern="Identity" /> 
       <Property Name="Name" Type="nvarchar" Nullable="false" MaxLength="100" /> 
       <Property Name="ResourceId" Type="int" Nullable="false" /> 
      </EntityType> 
      <EntityType Name="Resources"> 
       <Key> 
       <PropertyRef Name="ResourceId" /> 
       </Key> 
       <Property Name="ResourceId" Type="int" Nullable="false" StoreGeneratedPattern="Identity" /> 
       <Property Name="Description" Type="nvarchar" MaxLength="50" /> 
      </EntityType> 
      <EntityType Name="sysdiagrams"> 
       <Key> 
       <PropertyRef Name="diagram_id" /> 
       </Key> 
       <Property Name="name" Type="nvarchar" Nullable="false" MaxLength="128" /> 
       <Property Name="principal_id" Type="int" Nullable="false" /> 
       <Property Name="diagram_id" Type="int" Nullable="false" StoreGeneratedPattern="Identity" /> 
       <Property Name="version" Type="int" /> 
       <Property Name="definition" Type="varbinary(max)" /> 
      </EntityType> 
      <EntityType Name="Users"> 
       <Key> 
       <PropertyRef Name="UserID" /> 
       </Key> 
       <Property Name="UserID" Type="uniqueidentifier" Nullable="false" /> 
       <Property Name="LocationId" Type="int" /> 
      </EntityType> 
      <EntityType Name="Votes"> 
       <Key> 
       <PropertyRef Name="VoteId" /> 
       </Key> 
       <Property Name="VoteId" Type="int" Nullable="false" /> 
       <Property Name="VoterId" Type="uniqueidentifier" Nullable="false" /> 
       <Property Name="VoteContent" Type="int" Nullable="false" /> 
       <Property Name="PostId" Type="int" Nullable="false" /> 
      </EntityType> 
      <Association Name="FK_Comments_Offers"> 
       <End Role="Offers" Type="XDbModel.Store.Offers" Multiplicity="0..1" /> 
       <End Role="Comments" Type="XDbModel.Store.Comments" Multiplicity="*" /> 
       <ReferentialConstraint> 
       <Principal Role="Offers"> 
        <PropertyRef Name="OfferID" /> 
       </Principal> 
       <Dependent Role="Comments"> 
        <PropertyRef Name="OfferPostID" /> 
       </Dependent> 
       </ReferentialConstraint> 
      </Association> 
      <Association Name="FK_Comments_Users"> 
       <End Role="Users" Type="XDbModel.Store.Users" Multiplicity="1"> 
       <OnDelete Action="Cascade" /> 
       </End> 
       <End Role="Comments" Type="XDbModel.Store.Comments" Multiplicity="*" /> 
       <ReferentialConstraint> 
       <Principal Role="Users"> 
        <PropertyRef Name="UserID" /> 
       </Principal> 
       <Dependent Role="Comments"> 
        <PropertyRef Name="UserID" /> 
       </Dependent> 
       </ReferentialConstraint> 
      </Association> 
      <Association Name="FK_LocationPoints_Locations"> 
       <End Role="Locations" Type="XDbModel.Store.Locations" Multiplicity="1"> 
       <OnDelete Action="Cascade" /> 
       </End> 
       <End Role="LocationPoints" Type="XDbModel.Store.LocationPoints" Multiplicity="*" /> 
       <ReferentialConstraint> 
       <Principal Role="Locations"> 
        <PropertyRef Name="LocationId" /> 
       </Principal> 
       <Dependent Role="LocationPoints"> 
        <PropertyRef Name="LocationId" /> 
       </Dependent> 
       </ReferentialConstraint> 
      </Association> 
      <Association Name="FK_PostBundleJunction_Bundles"> 
       <End Role="Bundles" Type="XDbModel.Store.Bundles" Multiplicity="1" /> 
       <End Role="PostBundleJunction" Type="XDbModel.Store.PostBundleJunction" Multiplicity="*" /> 
       <ReferentialConstraint> 
       <Principal Role="Bundles"> 
        <PropertyRef Name="BundleId" /> 
       </Principal> 
       <Dependent Role="PostBundleJunction"> 
        <PropertyRef Name="BundleId" /> 
       </Dependent> 
       </ReferentialConstraint> 
      </Association> 
      <Association Name="FK_PostBundleJunction_Posts"> 
       <End Role="Posts" Type="XDbModel.Store.Posts" Multiplicity="1" /> 
       <End Role="PostBundleJunction" Type="XDbModel.Store.PostBundleJunction" Multiplicity="*" /> 
       <ReferentialConstraint> 
       <Principal Role="Posts"> 
        <PropertyRef Name="PostId" /> 
       </Principal> 
       <Dependent Role="PostBundleJunction"> 
        <PropertyRef Name="PostId" /> 
       </Dependent> 
       </ReferentialConstraint> 
      </Association> 
      <Association Name="FK_Posts_Locations"> 
       <End Role="Locations" Type="XDbModel.Store.Locations" Multiplicity="1" /> 
       <End Role="Posts" Type="XDbModel.Store.Posts" Multiplicity="*" /> 
       <ReferentialConstraint> 
       <Principal Role="Locations"> 
        <PropertyRef Name="LocationId" /> 
       </Principal> 
       <Dependent Role="Posts"> 
        <PropertyRef Name="LocationId" /> 
       </Dependent> 
       </ReferentialConstraint> 
      </Association> 
      <Association Name="FK_Posts_ResourceNames"> 
       <End Role="ResourceNames" Type="XDbModel.Store.ResourceNames" Multiplicity="1" /> 
       <End Role="Posts" Type="XDbModel.Store.Posts" Multiplicity="*" /> 
       <ReferentialConstraint> 
       <Principal Role="ResourceNames"> 
        <PropertyRef Name="ResourceNameId" /> 
       </Principal> 
       <Dependent Role="Posts"> 
        <PropertyRef Name="ResourceNameId" /> 
       </Dependent> 
       </ReferentialConstraint> 
      </Association> 
      <Association Name="FK_Posts_Users"> 
       <End Role="Users" Type="XDbModel.Store.Users" Multiplicity="1" /> 
       <End Role="Posts" Type="XDbModel.Store.Posts" Multiplicity="*" /> 
       <ReferentialConstraint> 
       <Principal Role="Users"> 
        <PropertyRef Name="UserID" /> 
       </Principal> 
       <Dependent Role="Posts"> 
        <PropertyRef Name="PosterID" /> 
       </Dependent> 
       </ReferentialConstraint> 
      </Association> 
      <Association Name="FK_ResourceEdges_Resources"> 
       <End Role="Resources" Type="XDbModel.Store.Resources" Multiplicity="1" /> 
       <End Role="ResourceEdges" Type="XDbModel.Store.ResourceEdges" Multiplicity="*" /> 
       <ReferentialConstraint> 
       <Principal Role="Resources"> 
        <PropertyRef Name="ResourceId" /> 
       </Principal> 
       <Dependent Role="ResourceEdges"> 
        <PropertyRef Name="ToResourceId" /> 
       </Dependent> 
       </ReferentialConstraint> 
      </Association> 
      <Association Name="FK_ResourceEdges_Resources1"> 
       <End Role="Resources" Type="XDbModel.Store.Resources" Multiplicity="1" /> 
       <End Role="ResourceEdges" Type="XDbModel.Store.ResourceEdges" Multiplicity="*" /> 
       <ReferentialConstraint> 
       <Principal Role="Resources"> 
        <PropertyRef Name="ResourceId" /> 
       </Principal> 
       <Dependent Role="ResourceEdges"> 
        <PropertyRef Name="FromResourrceId" /> 
       </Dependent> 
       </ReferentialConstraint> 
      </Association> 
      <Association Name="FK_ResourceNames_Resources"> 
       <End Role="Resources" Type="XDbModel.Store.Resources" Multiplicity="1"> 
       <OnDelete Action="Cascade" /> 
       </End> 
       <End Role="ResourceNames" Type="XDbModel.Store.ResourceNames" Multiplicity="*" /> 
       <ReferentialConstraint> 
       <Principal Role="Resources"> 
        <PropertyRef Name="ResourceId" /> 
       </Principal> 
       <Dependent Role="ResourceNames"> 
        <PropertyRef Name="ResourceId" /> 
       </Dependent> 
       </ReferentialConstraint> 
      </Association> 
      <Association Name="FK_Users_Locations"> 
       <End Role="Locations" Type="XDbModel.Store.Locations" Multiplicity="0..1"> 
       <OnDelete Action="Cascade" /> 
       </End> 
       <End Role="Users" Type="XDbModel.Store.Users" Multiplicity="*" /> 
       <ReferentialConstraint> 
       <Principal Role="Locations"> 
        <PropertyRef Name="LocationId" /> 
       </Principal> 
       <Dependent Role="Users"> 
        <PropertyRef Name="LocationId" /> 
       </Dependent> 
       </ReferentialConstraint> 
      </Association> 
      <Association Name="FK_Votes_Posts"> 
       <End Role="Posts" Type="XDbModel.Store.Posts" Multiplicity="1"> 
       <OnDelete Action="Cascade" /> 
       </End> 
       <End Role="Votes" Type="XDbModel.Store.Votes" Multiplicity="*" /> 
       <ReferentialConstraint> 
       <Principal Role="Posts"> 
        <PropertyRef Name="PostId" /> 
       </Principal> 
       <Dependent Role="Votes"> 
        <PropertyRef Name="PostId" /> 
       </Dependent> 
       </ReferentialConstraint> 
      </Association> 
      </Schema> 
     </edmx:StorageModels> 
     <!-- CSDL content --> 
     <edmx:ConceptualModels> 
      <Schema Namespace="XDbModel" Alias="Self" xmlns:annotation="http://schemas.microsoft.com/ado/2009/02/edm/annotation" xmlns="http://schemas.microsoft.com/ado/2008/09/edm"> 
      <EntityContainer Name="XDbEntities" annotation:LazyLoadingEnabled="true"> 
       <EntitySet Name="Bundles" EntityType="XDbModel.Bundle" /> 
       <EntitySet Name="CellProviders" EntityType="XDbModel.CellProvider" /> 
       <EntitySet Name="Comments" EntityType="XDbModel.Comment" /> 
       <EntitySet Name="LocationPoints" EntityType="XDbModel.LocationPoint" /> 
       <EntitySet Name="Locations" EntityType="XDbModel.Location" /> 
       <EntitySet Name="Offers" EntityType="XDbModel.Offer" /> 
       <EntitySet Name="PostMedias" EntityType="XDbModel.PostMedia" /> 
       <EntitySet Name="Posts" EntityType="XDbModel.Post" /> 
       <EntitySet Name="ResourceEdges" EntityType="XDbModel.ResourceEdge" /> 
       <EntitySet Name="ResourceNames" EntityType="XDbModel.ResourceName" /> 
       <EntitySet Name="Resources" EntityType="XDbModel.Resource" /> 
       <EntitySet Name="sysdiagrams" EntityType="XDbModel.sysdiagram" /> 
       <EntitySet Name="Users" EntityType="XDbModel.User" /> 
       <EntitySet Name="Votes" EntityType="XDbModel.Vote" /> 
       <AssociationSet Name="FK_Comments_Offers" Association="XDbModel.FK_Comments_Offers"> 
       <End Role="Offers" EntitySet="Offers" /> 
       <End Role="Comments" EntitySet="Comments" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_Comments_Users" Association="XDbModel.FK_Comments_Users"> 
       <End Role="Users" EntitySet="Users" /> 
       <End Role="Comments" EntitySet="Comments" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_LocationPoints_Locations" Association="XDbModel.FK_LocationPoints_Locations"> 
       <End Role="Locations" EntitySet="Locations" /> 
       <End Role="LocationPoints" EntitySet="LocationPoints" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_Posts_Locations" Association="XDbModel.FK_Posts_Locations"> 
       <End Role="Locations" EntitySet="Locations" /> 
       <End Role="Posts" EntitySet="Posts" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_Users_Locations" Association="XDbModel.FK_Users_Locations"> 
       <End Role="Locations" EntitySet="Locations" /> 
       <End Role="Users" EntitySet="Users" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_Posts_ResourceNames" Association="XDbModel.FK_Posts_ResourceNames"> 
       <End Role="ResourceNames" EntitySet="ResourceNames" /> 
       <End Role="Posts" EntitySet="Posts" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_Posts_Users" Association="XDbModel.FK_Posts_Users"> 
       <End Role="Users" EntitySet="Users" /> 
       <End Role="Posts" EntitySet="Posts" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_Votes_Posts" Association="XDbModel.FK_Votes_Posts"> 
       <End Role="Posts" EntitySet="Posts" /> 
       <End Role="Votes" EntitySet="Votes" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_ResourceEdges_Resources" Association="XDbModel.FK_ResourceEdges_Resources"> 
       <End Role="Resources" EntitySet="Resources" /> 
       <End Role="ResourceEdges" EntitySet="ResourceEdges" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_ResourceEdges_Resources1" Association="XDbModel.FK_ResourceEdges_Resources1"> 
       <End Role="Resources" EntitySet="Resources" /> 
       <End Role="ResourceEdges" EntitySet="ResourceEdges" /> 
       </AssociationSet> 
       <AssociationSet Name="FK_ResourceNames_Resources" Association="XDbModel.FK_ResourceNames_Resources"> 
       <End Role="Resources" EntitySet="Resources" /> 
       <End Role="ResourceNames" EntitySet="ResourceNames" /> 
       </AssociationSet> 
       <AssociationSet Name="PostBundleJunction" Association="XDbModel.PostBundleJunction"> 
       <End Role="Bundles" EntitySet="Bundles" /> 
       <End Role="Posts" EntitySet="Posts" /> 
       </AssociationSet> 
      </EntityContainer> 
      <EntityType Name="Bundle"> 
       <Key> 
       <PropertyRef Name="BundleId" /> 
       </Key> 
       <Property Name="BundleId" Type="Int32" Nullable="false" /> 
       <NavigationProperty Name="Posts" Relationship="XDbModel.PostBundleJunction" FromRole="Bundles" ToRole="Posts" /> 
      </EntityType> 
      <EntityType Name="CellProvider"> 
       <Key> 
       <PropertyRef Name="CellProviderID" /> 
       </Key> 
       <Property Name="CellProviderID" Type="Guid" Nullable="false" /> 
      </EntityType> 
      <EntityType Name="Comment"> 
       <Key> 
       <PropertyRef Name="CommentID" /> 

Answer 1

Ah, es realmente muy simple, una vez que se piensa en ello .. Lo que estamos tratando de hacer es añadir el recurso al contexto de datos, aunque este objeto de recurso se recibió de la base de datos en primer lugar. ¡Entonces el error no se queja de los objetos de su hijo, sino de su objeto primario! :)

Básicamente, si comenta la primera línea del método SaveResource(), ¡debería funcionar bien! ej .:

public void SaveResource(Resource resource) 
{ 
    // context.AddToResources(resource); //Should also add children. 
    context.SaveChanges(); 
} 

O simplemente mover el método AddChildResource a su DAL:

public void AddChildResource(int parentResourceId, Resource childResource) 
{ 
    Resource parentResource = repository.GetResource(parentResourceId); 

    ResourceEdge inEdge = new ResourceEdge(); 
    inEdge.ToResource = childResource; 

    parentResource.ToEdges.Add(inEdge); 

    context.SaveChanges(); 
} 

Answer 2

Es de suponer que se queja de la childResource no estar en el estado agregado. Lo ha agregado al objeto de borde que está en el estado agregado.

Se puede tratar voltear la forma en que se establece la asociación ronda: -

public void AddChildResource(int parentResourceId, Resource childResource) 
{ 
    Resource parentResource = repository.GetResource(parentResourceId); 

    ResourceEdge inEdge = new ResourceEdge(); 
    // inEdge.ToResource = childResource; <-- don't do this 

    parentResource.ToEdges.Add(inEdge); 
    childResource.FromEdges.Add(inEdge); // try this instead 

    repository.SaveResource(parentResource); 
} 

Answer 3

Ya hemos publicado un código relativo a recommendation on MSDN similar a la suya.
¿Fue útil?