Custom MarkupExtension with properties

Question

I have created a MarkupExtension that exposes a Converter property of the Type IValueConverter, the Intellisens in visual studio finds it but when I try to compile I get the following error: Unknown property 'Converter' for type 'MS.Internal.Markup.MarkupExtensionParser+UnknownMarkupExtension' encountered while parsing a Markup Extension.

EnumItemSourceBinding:

Public Class EnumItemSourceBinding
    Inherits MarkupExtension
    Implements INotifyPropertyChanged

    Private mEnumType As Type
    Private mConverter As IValueConverter

    <DefaultValue(CObj(Nothing))>
    Public Property EnumType As Type
        Get
            Return mEnumType
        End Get
        Set(value As Type)
            mEnumType = value
            OnPropertyChanged(NameOf(EnumType))
            mBindingChanged = True
        End Set
    End Property

    <DefaultValue(CObj(Nothing))>
    Public Property Converter As IValueConverter
        Get
            Return mConverter
        End Get
        Set(value As IValueConverter)
            mConverter = value
            OnPropertyChanged(NameOf(Converter))
            mBindingChanged = True
        End Set
    End Property

    Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged

    Public Sub New()
        MyBase.New()

    End Sub

    Public Sub New(enumType As Type)
        MyBase.New()
        mEnumType = enumType
    End Sub

    Private Sub OnPropertyChanged(ByVal propertyName As String)
        RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(propertyName))
    End Sub
End Class

Xaml: {local:EnumItemSourceBinding {x:Type local:BoundTextFields}, Converter={StaticResource EnumToTextConverter}}

Why do I get the compilation error?

Answer 1

It seems you can't define the MarkupExtension in the same assembly where you want to use it so I had to split it out.