Hi, I want to filter a collectionviewsource using a filter I've written, but I'm not sure how I can apply the filter to it?

Here is my collection view source:

    <Grid.Resources>
        <CollectionViewSource x:Key="myCollectionView" 
           Source="{Binding Path=Query4, Source={x:Static Application.Current}}">
            <CollectionViewSource.SortDescriptions>
                <scm:SortDescription PropertyName="ContactID" 
                                     Direction="Descending"/>
            </CollectionViewSource.SortDescriptions>
        </CollectionViewSource>
    </Grid.Resources>

I have implemented a filter as such:

    Private Sub WorkerFilter(ByVal sender As Object, ByVal e As FilterEventArgs)

    Dim value As Object = CType(e.Item, System.Data.DataRow)("StaffSection")

    If (Not value Is Nothing) And (Not value Is DBNull.Value) Then
        If (value = "Builder") Or (value = "Office Staff") Then
            e.Accepted = True

        Else

            e.Accepted = False
        End If
    End If
End Sub

So how can I get the CollectionViewSource filtered by the filter on load? Could you please give all hte code I need (only a few lines I figure) as I'm quite new to coding.

Thanks guys

EDIT: For the record,

  <CollectionViewSource x:Key="myCollectionView" Filter="WorkerFilter" ... />

gives me the error:

Failed object initialization (ISupportInitialize.EndInit). 'System.Windows.Data.BindingListCollectionView' view does not support filtering. Error at object 'myCollectionView'