Basic WCF question

I usually can create an instance of a class called SalesItem and pass that as a parameter to a web service like so webService.CreateSalesitem(New SalesItem()) This works fine.

I then subclassed my SalesItem class. I called it GP_Item_SIM_Product. However when I try to pass this class as a paramter to my web service, I get an exception. webService.CreateSalesitem(new GP_Item_SIM_Product())

Here is the exception:

There was an error while trying to serialize parameter http://schemas.microsoft.com/dynamics/gp/2010/01:salesItem. The InnerException message was 'Type 'IMS.GP_Item_SIM_Product' with data contract name 'GP_Item_SIM_Product:http://schemas.datacontract.org/2004/07/IMS' is not expected. Consider using a DataContractResolver or add any types not known statically to the list of known types - for example, by using the KnownTypeAttribute attribute or by adding them to the list of known types passed to DataContractSerializer.'. Please see InnerException for more details.

Here is my subclass:

Imports System.ServiceModel
Imports GP_1.DynamicsGPClient
Imports GP_1.Microsoft.Dynamics.GP
Imports GP_1.Microsoft.Dynamics.Common
Imports SierraLib
Imports GP_1.GP
Imports GP_1
Imports System.Runtime.Serialization

< DataContract() > _
Public Cla开发者_如何学Css GP_Item_SIM_Product
    Inherits SalesItem

    Dim SIMProduct As Products
    Dim greatPlainsRunner As GPRunner

    Public Sub New(ByVal gpr As GPRunner, ByVal product As Products)
        SIMProduct = product
        greatPlainsRunner = gpr
        SetValues()
    End Sub

    Private Sub SetValues()
        Me.Key = New ItemKey() With {.Id = SIMProduct.MFGPN}
        Me.Description = Description
        Me.CurrentCost = New MoneyAmount() With {.Currency = Defaults.usCurrency, .Value = CDec(SIMProduct.Cost)}
        Me.StandardCost = New MoneyAmount() With {.Currency = Defaults.usCurrency, .Value = CDec(SIMProduct.Price)}
        Me.IsDiscontinued = Not SIMProduct.Enabled
        Me.SalesTaxBasis = IIf(CBool(SIMProduct.Taxed = True),
                            GP_1.Microsoft.Dynamics.GP.SalesTaxBasis.Taxable,
                            GP_1.Microsoft.Dynamics.GP.SalesTaxBasis.Nontaxable)
    End Sub


End Class

Any ideas how I can modify my class so that it can be sent to the web service. I think it has something to do with the two fields in this class that I added. Not sure if I need to mark them as anything special.

Try adding <ServiceKnownType(GetType(GP_Item_SIM_Product))> to your service contract.

You need to add the ServiceKnownType attribute to the service contract - that's the Interface that defines your serivce and contains the signature for the CreateSalesitem operation.

<ServiceKnownType(GetType(GP_Item_SIM_Product))> 
Public Interface IWebService