WithEvents oddness CslaDataSource and VB.Net

jas_nhs posted on Wednesday, August 02, 2006

    Whist an old hand at VB6 and more used to C#, I have an odd problem when using a number of CslaDataSources on a user contro, with the less-familiar VB.Netl. The "select" event handler is created in the predictable way:

  Protected Sub CslaDSUserAdmin_SelectObject(ByVal sender As Object, ByVal e As Csla.Web.SelectObjectArgs) Handles CslaDSUserAdmin.SelectObject
    e.BusinessObject = UserAccounts.GetUserAccounts()
  End Sub

but, on my home PC this throws a build error:

Handles clause requires a WithEvents variable defined in the containing type or one of its base types.

The ascx code is simply:
<cc1:CslaDataSource ID="CslaDSUserAdmin" runat="server" TypeAssemblyName="OSALib.SA.BusinessObjects"
  TypeName="OSALib.SA.BusinessObjects.UserAccount">
</cc1:CslaDataSource>

If I comment out the "handles..." bit, the above sub is not invoked (of course) and no records are read.
What to do???  I am using V2.0.3 of csla.dll (ref Assembly Version, in the file properties)
I'm wondering if this msg might be vaguely relevant: http://forums.lhotka.net/forums/post/2099.aspx

Many thanks for any guidance,

James.

xal replied on Wednesday, August 02, 2006

I'm not that much into web, but in windows forms (or just in a simple class), you need to do this:

Private WithEvents mInstanceName as SomeType

If for some reason you can't do that, you can do it as you would in c# with an addhandler in a constructor or in a load event, like:
AddHandler mInstanceName.EventName, AddressOf methodName


That way, you don't need to use the "Handles". To remove the handler the sintax is exactly the same except you use RemoveHandler.