Public Class TrueToFalse
   Implements IValueConverter

   Public Function Convert(value As Object, targetType As Type, parameter As Object, culture As System.Globalization.CultureInfo) As Object Implements IValueConverter.Convert
      Return Not CBool(value)
   End Function

   Public Function ConvertBack(value As Object, targetType As Type, parameter As Object, culture As System.Globalization.CultureInfo) As Object Implements IValueConverter.ConvertBack
      Throw New NotImplementedException
   End Function
End Class