BeginCreate of dataportal is not creating object from silverlight client

shivam.ms posted on Monday, January 23, 2012

I am trying to create a test project using csla .net for silverlight 4.2.2.  I used the SimpleApp sample project in VB and one server class of .Net library project and one client class of SilverLight library project and one SilverLight application for UI. When I try to create a object from server class via call by Dataportal implementatin for SilverLight, it is working correctly.  Call to BeginCreate is done successfully but when i try to use the object returned by callback method, the error "NULLObjectReferenceException" error is thrown. Please refer the code below:

 Server/Client object Factory and Data Access code:

#Region " Silverlight Data Access "
#If SILVERLIGHT Then
    'Factory Methods starts
    Public Shared Sub BeginNewPatient(ByVal proxyMode As DataPortal.ProxyModes, ByVal callback As EventHandler(Of DataPortalResult(Of Patient)))

        Dim dp As New DataPortal(Of Patient)(proxyMode)
        AddHandler dp.CreateCompleted, callback
        dp.BeginCreate()
    End Sub

    Public Shared Sub BeginGetPatient(ByVal id As Guid, ByVal callback As EventHandler(Of DataPortalResult(Of Patient)))

        Dim dp As New DataPortal(Of Patient)
        AddHandler dp.FetchCompleted, callback
        dp.BeginFetch(New SingleCriteria(Of Patient, Guid)(id))
    End Sub
    Public Shared Sub BeginDeletePatient(ByVal id As Guid, ByVal callback As EventHandler(Of DataPortalResult(Of Patient)))

        Dim dp As New DataPortal(Of Patient)
        AddHandler dp.DeleteCompleted, callback
        dp.BeginDelete(New SingleCriteria(Of Patient, Guid)(id))
    End Sub

    Public Sub New()
        ' required by MobileFormatter
    End Sub
    'Factory Methods ends

    Public Overrides Sub DataPortal_Create( _
      ByVal handler As Csla.DataPortalClient.LocalProxy(Of Patient).CompletedHandler)

        Dim bw As New System.ComponentModel.BackgroundWorker
        AddHandler bw.DoWork, AddressOf DoCreate
        AddHandler bw.RunWorkerCompleted, AddressOf DoCreateComplete
        bw.RunWorkerAsync(handler)
    End Sub

    Private Sub DoCreate(ByVal sender As Object, ByVal e As System.ComponentModel.DoWorkEventArgs)
        e.Result = e.Argument
    End Sub

    Private Sub DoCreateComplete(ByVal sender As Object, ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs)
        Dim handler As Csla.DataPortalClient.LocalProxy(Of Patient).CompletedHandler
        handler = CType(e.Result, Csla.DataPortalClient.LocalProxy(Of Patient).CompletedHandler)
        Try
            Using BypassPropertyChecks
                Status = "Created " & ApplicationContext.ExecutionLocation.ToString
            End Using
            MyBase.DataPortal_Create(handler)
        Catch ex As Exception
            handler(Me, ex)
        End Try
    End Sub
#End Region

SilverLight UI Code:

 Partial Public Class MainPage
    Inherits UserControl
    Public Sub New()
        InitializeComponent()
    End Sub
    Private WithEvents _provider As CslaDataProvider
    Private Sub BindPatient(ByVal sender As Object, ByVal e As Csla.DataPortalResult(Of PTAppScheduler.Patient))
        Dim p1 As Patient = New Patient
        p1 = e.Object
        p1.Name = TextBox1.Text
    End Sub
    Private Sub Button_Click(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs)
        Dim id As System.Guid
        id = New Guid("866B76E9-614B-4406-98E5-18EF236C8673")
        PTAppScheduler.Patient.BeginNewPatient(Csla.DataPortal.ProxyModes.Auto, AddressOf BindPatient)
    End Sub
    Private Sub Delete_Click(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs)

    End Sub
End Class

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

#Region

 

 

 

" Silverlight Data Access "

 

#If 

 

 

 

SILVERLIGHT

 

 

Then

 

 

 

 

 

'Factory Methods starts

 

 

 

 

Public Shared Sub BeginNewPatient(ByVal proxyMode As DataPortal.ProxyModes, ByVal callback As EventHandler(Of DataPortalResult(Of Patient

 

)))

 

 

 

Dim dp As New DataPortal(Of Patient

)(proxyMode)

 

 

 

AddHandler

dp.CreateCompleted, callback

dp.BeginCreate()

 

 

 

End

Sub

 

 

 

 

Public Shared Sub BeginGetPatient(ByVal id As Guid, ByVal callback As EventHandler(Of DataPortalResult(Of Patient

 

)))

 

 

 

Dim dp As New DataPortal(Of Patient

)

 

 

 

AddHandler

dp.FetchCompleted, callback

dp.BeginFetch(

 

 

New SingleCriteria(Of Patient, Guid

)(id))

 

 

 

End

Sub

 

 

 

 

Public Shared Sub BeginDeletePatient(ByVal id As Guid, ByVal callback As EventHandler(Of DataPortalResult(Of Patient

 

)))

 

 

 

Dim dp As New DataPortal(Of Patient

)

 

 

 

AddHandler

dp.DeleteCompleted, callback

dp.BeginDelete(

 

 

New SingleCriteria(Of Patient, Guid

)(id))

 

 

 

End

Sub

 

 

 

 

Public Sub New

 

()

 

 

 

' required by MobileFormatter

 

 

 

 

End

 

Sub

 

 

 

 

 

'Factory Methods ends

 

 

 

 

Public Overrides Sub

 

DataPortal_Create( _

 

 

 

ByVal handler As Csla.DataPortalClient.LocalProxy(Of Patient).CompletedHandler

)

 

 

 

Dim bw As New System.ComponentModel.

BackgroundWorker

 

 

 

 

AddHandler bw.DoWork, AddressOf

 

DoCreate

 

 

 

AddHandler bw.RunWorkerCompleted, AddressOf

DoCreateComplete

bw.RunWorkerAsync(handler)

 

 

 

End

Sub

 

 

 

 

Private Sub DoCreate(ByVal sender As Object, ByVal e As System.ComponentModel.DoWorkEventArgs

 

)

e.Result = e.Argument

 

 

 

End

Sub

 

 

 

 

Private Sub DoCreateComplete(ByVal sender As Object, ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs

 

)

 

 

 

Dim handler As Csla.DataPortalClient.LocalProxy(Of Patient).

CompletedHandler

 

handler =

 

 

CType(e.Result, Csla.DataPortalClient.LocalProxy(Of Patient).CompletedHandler

 

)

 

 

 

Try

 

 

 

 

Using

 

BypassPropertyChecks

Status =

 

 

"Created " & ApplicationContext

.ExecutionLocation.ToString

 

 

 

End

Using

 

 

 

 

MyBase

 

.DataPortal_Create(handler)

 

 

 

Catch ex As

Exception

 

handler(

 

 

Me

 

, ex)

 

 

 

End

Try

 

 

 

 

End

 

Sub

#End

 

 

 

Region