Q:

New cannot be used in a class that is MustInherit WPF VB.NET

I have the following code in vb.net. I am using WPF and in the XAML i have a Convertor on the Image. Basically the Image based on the Status level should show a particular Image.
I am having trouble with this syntax. I have an error on "ImageSource" as it says 
"New cannot be used in a class that is MustInherit." I tried removing the New and declaring ImageSource as a String, but the code doesn't return anything into my XAML. What do I need to do?!?
    Public Function Convert(ByVal value As Object, _ 
                            ByVal targetType As System.Type, 
                            ByVal parameter As Object, 
                            ByVal culture As System.Globalization.CultureInfo) _ 
        As Object Implements System.Windows.Data.IValueConverter.Convert
    Dim EstadoIndex As Integer
    If Integer.TryParse(value.ToString, EstadoIndex) Then
        Select Case EstadoIndex
            Case 1
                Return New ImageSource("/Cogent;component/Images/Green.png")
            Case 2
                Return New ImageSource("/Cogent;component/Images/Red.png")
            Case Else
                Return New ImageSource("/Cogent;component/Images/White.png")
        End Select
    Else
        Return New ImageSource("/Cogent;component/Images/White.png")
    End If
End Function

A:

ImageSource is an abstract class (I guess MustInherit this is how you name abstract in VB.NET). If you want to return image you can use BitmapImage, which will load image in memory for you, use new BitmapImage(new Uri("/Cogent;component/Images/Green.png"))
Also if you need to set it to Image.Source - you can just return string, Image will load the image.

