WPF - Access the parent Control from inside a Style Setter ControlTemplate - wpf

Question

When making controls non-amendable we display them as a TextBox to keep a consistent style. The problem is that a ComboBox can have any type of data so binding the Text property of the ControlTemplate TextBox is not as simple as using SelectedItem.
<Style TargetType="{x:Type ComboBox}">
<Style.Triggers>
<Trigger Property="IsReadOnly" Value="True">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate>
<TextBox Text="{Binding RelativeSource={RelativeSource AncestorType={x:Type ComboBox}}, Path=????, Converter={StaticResource ResourceKey=ComboToTextConverter}, UpdateSourceTrigger=PropertyChanged}" />
</ControlTemplate>
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
</Style>
The idea I have is to use a Converter and send the whole ComboBox so it can be handled by the Converter code. Is there anyway to do this?
Any other suggestions are welcome!

Answer 1

you need to use the SelectedValue and SelectedValuePath properties:
<Style TargetType="ComboBox" x:Key="cStyle">
<Style.Triggers>
<Trigger Property="IsReadOnly" Value="True">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ComboBox">
<TextBox Text="{Binding RelativeSource=
{RelativeSource TemplatedParent},
Path=SelectedValue}" />
</ControlTemplate>
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
and heres your ComboBox
<ComboBox Name="cbox" ItemsSource="{Binding}"
Style="{StaticResource cStyle}"
SelectedValuePath="SomeText"
DisplayMemberPath="SomeText" />
now when you set the IsReadOnly property to true on the ComboBox, it turns into a TextBox with the selected value as its text.