Question

I have a table with 6400 rows. This is a parent-children table, it has a foreign key to it self (a self-association reference in EF).

For this project, all tree must be loaded (load data when node is expanded is not a solution for me)

I have tried to load all nodes/tree at a time, but it exceed maximun items: “The InnerException message was ‘Maximum number of items that can be serialized or deserialized in an object graph is ‘65536’.”

Then I have tried to load data recursively, but maximun simultanius connections are maded (http://msdn.microsoft.com/en-us/library/cc304129%28VS.85%29.aspx). This is because loadoperation is asyncronous and recursion runs un parallel way.

Finaly I have write this code to load the data, it works (slowly) but I think that this is dirty solution:

Private Sub loadOperation_Completed(ByVal sender As Object, ByVal e As EventArgs)

        Dim localloadOperation As LoadOperation(Of dimActivitats) = DirectCast(sender, LoadOperation(Of dimActivitats))

        If Not localloadOperation.HasError Then
            Dim llista = localloadOperation.Entities.ToList
            If llista.Any AndAlso llista.First.idSubrogatPare Is Nothing Then
                activitatsTree = llista
                TreeViewTaula.DataContext = activitatsTree
            End If

            For Each i In llista
                elementsWaitingForExpand.Push(i)
            Next
        End If

        Dim take10 = 10
        Dim IdsParentListOfElementsToProcessNow As New List(Of Integer)
        While elementsWaitingForExpand.Count > 0 And take10 > 0
            take10 -= 1
            IdsParentListOfElementsToProcessNow.Add(elementsWaitingForExpand.Pop.idSubrogat)
        End While
        Dim q2 = CActx.GetDimActivitatsListChildQuery(IdsParentListOfElementsToProcessNow)
        loadOperation = CActx.Load(Of dimActivitats)(q2)
        AddHandler loadOperation.Completed, AddressOf loadOperation_Completed

        ProgressBarTaula.Value = CActx.dimActivitats.Count

    End Sub

I’m looking for some thing more elegant (semaphor? monitor? queue? ).

---

Here you can see a previeus solution that raise error due simultanius connections:

Private Sub loadOperation_Completed(ByVal sender As Object, ByVal e As EventArgs)
    Try
        Dim localloadOperation As LoadOperation(Of dimActivitats) = DirectCast(sender, LoadOperation(Of dimActivitats))

        If Not localloadOperation.HasError Then
            Dim llista = localloadOperation.Entities.ToList
            If llista.Any AndAlso llista.First.idSubrogatPare Is Nothing Then
                activitatsTree = llista
                TreeViewTaula.DataContext = activitatsTree

            End If

            TreeViewTaula.Dispatcher.BeginInvoke(New loadLlistaDelegate(AddressOf loadLlista), llista)
        End If
    Catch ex As Exception
    End Try
End Sub

Private Delegate Sub loadLlistaDelegate(ByVal llista As List(Of dimActivitats))
Private Sub loadLlista(ByVal llista As List(Of dimActivitats))
    For Each item In llista
        For Each fill In item.dimActivitatsChildren
            Dim q2 = CActx.GetDimActivitatsChildQuery(fill.idSubrogat)
            Dim newloadOperation = CActx.Load(Of dimActivitats)(q2)
            AddHandler newloadOperation.Completed, AddressOf loadOperation_Completed
        Next
    Next
End Sub

---

Do you have any idea to rewrite this code in more elegant way?

Answer 1

Do you have the maxItemsInObjectGraph setting in your service behavior in the web.config set to the maximum ? e.g

  <system.serviceModel>
    <behaviors>
      <serviceBehaviors>
        <!--The service behavior for the RIA Service-->
        <behavior name="RIAServiceBehavior">
          <serviceMetadata httpGetEnabled="true" />
          <serviceDebug includeExceptionDetailInFaults="true" />
          <dataContractSerializer **maxItemsInObjectGraph="2147483647"** />