protected override XamlValueConverter <TypeConverter> LookupTypeConverter() { TypeConverter converter = Descriptor.GetConverter(); if (converter == null || ConverterHelper.IsNonXaml(converter)) { if (ConverterHelper.HasXamlSpecificBuiltInConverter(UnderlyingType)) { return(base.LookupTypeConverter()); } return(null); } return(new SpecifiedInstanceValueConverter(converter)); }