In WPF, how to add an EventHandler for a FrameworkElement designed in Template?

Question

I have defined the following DataTemplate for ListBox items in an external resource dictionary:

Answer 1

Method 1: Use your own control inherited from Slider:

public class SpecialSlider : Slider
{
    public SpecialSlider()
    {
        ValueChanged += OnValueChanged;
    }

    private void OnValueChanged(object sender, RoutedPropertyChangedEventArgs e)
    {
        // ...
    }
}  

Method 2: use behaviors from System.Windows.Interactivity.dll assembly (available through the NuGet):

public class SpecialSliderBehavior : Behavior
{
    protected override void OnAttached()
    {
        base.OnAttached();
        AssociatedObject.ValueChanged += OnValueChanged;
    }

    protected override void OnDetaching()
    {
        base.OnDetaching();
        AssociatedObject.ValueChanged -= OnValueChanged;
    }

    private void OnValueChanged(object sender, RoutedPropertyChangedEventArgs e)
    {
        // ...
    }
}

This is how to attach it:

...
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
...