I wondering to make a ComboBoxTreeView,I've done it in main xaml:using the ControlTemplate,and change Content="{TemplateBinding SelectionBoxItem}"
into Content="{Binding SelectedItem.Header,ElementName=TreeView1}".
However,when I write it into ResourceDictionary, it not work. And,I don't know Content,ContentTemplate,and ContentTemplateSelector how to Binding in ResourceDictionary.