Combobox selectedValue missing in result of XamlWriter.Save

Few day ago I started to play with dynamic Xaml. I have noticed that using XamlWriter.Save method to serialize Combobox causes absence of selectedValue in result string. Text of se开发者_运维技巧lected element is in result but not the selectedValue. Does anyone have any idea how to save selectedValue so calling XamlReader.Parse(XamlWriter.Save(myComboBox)) won't loose SelectedValue.

My first thought was to implement some DependencyProperty ex. MySelectedValue.

If you suggest some other possibilities, I will be very grateful.

Is a property IsTextSearchEnabled set to true on the combobox? It could help to chose selected value from the text.