Silverlight 4 domainservice query does not return results

[Jdsurgeon]

Try
        Dim check = (From d In Me.ObjectContext.OrderMasters
                     Group d By d.ordnum Into g = Group
                     Order By ordnum Descending
                     Select ordnum).First
        Dim NewOrder As String = check & Date.Now.Millisecond.ToString
        Return NewOrder
    Catch ex As Exception
        Return "Could Not obtain order"
    End Try

this doesn't return anything like its not even running anybody have an idea why I can't get the value from the silverlight client.

[Lightning]

have you debugged? is there an exception?

[Jdsurgeon]

for some reason I am using the Silvelight business application template. I have debugged it but for some reason it does not ever hit this line of code. Even thouhg it is exposed through the domain service and I can execute it from the client but it always return null even though it should return something regardless of the exception.

[Jdsurgeon]

I know silvelright 4 is new but can somebody help?

[MattP]

Can you post a little more than the Try Catch block from your DomainService. Would also like to see how you're calling it from the client side.

[Jdsurgeon]

ok

	
	
Public Function ReturnNewOrderNumber() As String
Retry:
        Try
            Dim check = (From d In Me.ObjectContext.OrderMasters
                         Group d By d.ordnum Into g = Group
                         Order By ordnum Descending
                         Select ordnum).First
            Dim NewOrder As String = check & Date.Now.Millisecond.ToString
            Try
                Dim Check2 = (From e In Me.ObjectContext.OrderMasters Where e.ordnum = NewOrder Select e).First
                GoTo Retry
            Catch ex As Exception
                Return NewOrder
            End Try
        Catch ex As Exception
            Return "Could Not obtain order"
        End Try
    End Function

Private Sub Order_Loaded(sender As Object, e As System.Windows.RoutedEventArgs) Handles Me.Loaded
        ScheduleDatePicker.SelectedDate = Date.Now
        OrderDatePicker.SelectedDate = Date.Now
        Try
            Dim db As New KattDomContext
            orderdata = db.ReturnNewOrderNumber()
            AddHandler orderdata.Completed, AddressOf orderCompleted
            OrderNumberTextBox.IsEnabled = False
        Catch ex As Exception
 
        End Try
    End Sub
 
    Private Sub OrderRefreshButton_Click(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles OrderRefreshButton.Click
        OrderDetailDomainDataSource.Load()
    End Sub
 
    Private Sub orderCompleted(ByVal sender As Object, ByVal e As System.EventArgs)
        OrderNumberTextBox.Text = orderdata.Value
    End Sub

[Jdsurgeon]

Thanks matt

[MattP]

I'm going to pretend I didn't see the Retry: GoTo Retry in the code.

Here's the MSDN article on Domain Services: http://msdn.microsoft.com/en-us/libr...(v=vs.91).aspx

Try adding the <Invoke()> attribute to your ReturnNewOrderNumber method. If you don't specify this then the return type won't be IEnumerable<T>, IQueryable<T>, or Entity which the query can return. (The Domain Service will assume the <Query()> attribute unless your method name starts with Update, Change, Modify, Insert, Add, Create, Delete or Remove)

[Jdsurgeon]

Wow that worked. Actually I don't know of another way to retry a statement if the order exists. This is actually my first time doing it and I know it's bad code practice but what harm does it do when I know it won't ever just lock up like most go to statements. but if you have a better way please share I am not an expert.

[MattP]

I would use a loop so that you can keep looping until a certain condition is met (You have a unique Order Number in your case).

A quick Google search brought up this as the first result: http://www.startvbdotnet.com/language/loops.aspx Take a look at the While and Do loops.

[Jdsurgeon]

OMG can I add you as a friend I promise not bumbarded you with questions I am usually a Google look it up guy but I really appreciate your help and I got that nasty GOTO statement removed from my code.