WPF Binding in ItemTemplate for custom ItemControl - wpf

Question

I add a WPF custom control and make it derive from ItemsControl. The class is called IC4 and is declared as follows:
public class IC4 : ItemsControl
I add the following properties to it:
public class P
{
public string S { get; set; }
public string T { get; set; }
}
public List<P> LP { get; set; } = new List<P>();
Then in the constructor I do the following:
public IC4()
{
LP.Add(new P { S = "fred", T = "jim" });
LP.Add(new P { S = "fred", T = "jim" });
this.ItemsSource = LP;
this.DataContext = this;
}
Visual studio added a style entry to themes/generic.xaml - I have modified it as follows:
<Style TargetType="{x:Type local:IC4}">
<Setter Property="ItemTemplate">
<Setter.Value>
<DataTemplate>
<Grid>
<!-- this is almost certainly wrong: -->
<TextBlock Text="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=S}"/>
</Grid>
</DataTemplate>
</Setter.Value>
</Setter>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:IC4}">
<Border Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}">
<ItemsPresenter/>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
In mainwindow.xaml I added:
<StackPanel>
<Label Content="before"/>
<local:IC4 ItemsSource="{Binding LP}"/>
<Label Content="after"/>
</StackPanel>
I am fairly certain the binding for the Textbox in the data template is incorrect since I get the following runtime error (shown in the output window):
System.Windows.Data Error: 40 : BindingExpression path error: 'S' property not found on 'object' ''ContentPresenter' (Name='')'. BindingExpression:Path=S; DataItem='ContentPresenter' (Name=''); target element is 'TextBlock' (Name=''); target property is 'Text' (type 'String')
How do I set the binding to be able to show the S elements of the LP property?
(Note that for the sake of simplicity I am not interested in property change notifications).
Thanks

Answer 1

As far as I can see it should be just
<DataTemplate>
<Grid>
<TextBlock Text="{Binding Path=S}"/>
</Grid>
</DataTemplate>
DataContext of each item, so for everything in your ItemTemplate, will be an instance of P class so all you should need to specify is the Path