Preventing tab changes for TabControl

If we have a `TabControl` in a WPF application and we'd like to allow or not tab changes, the best way we can actually do it is by having an attached property like the following :

```cs
public static partial class TabControlHelper
{
public static readonly DependencyProperty PreventTabChangeProperty = DependencyProperty.RegisterAttached("PreventTabChange", typeof(bool), typeof(TabControlHelper), new PropertyMetadata(false, OnPreventTabChangeChanged));

public static bool GetPreventTabChange(TabControl tabControl)
{
return (bool)tabControl.GetValue(PreventTabChangeProperty);
}

public static void SetPreventTabChange(TabControl tabControl, bool value)
{
tabControl.SetValue(PreventTabChangeProperty, value);
}

private static void OnPreventTabChangeChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (e.NewValue is bool preventTabChanges && d is TabControl tabControl)
{
if (preventTabChanges)
{
tabControl.SelectionChanged += TabControl_SelectionChanged;
}
else
{
tabControl.SelectionChanged -= TabControl_SelectionChanged;
}
}
}

private static void TabControl_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (sender is TabControl tabControl && e.RemovedItems.Count > 0)
{
int prevIdx = tabControl.Items.IndexOf(e.RemovedItems[0]);
if (prevIdx != -1)
{
tabControl.SelectionChanged -= TabControl_SelectionChanged;
tabControl.SelectedIndex = prevIdx;
tabControl.SelectionChanged += TabControl_SelectionChanged;
}
}
}
}
```

It prevents tab changes properly but it has side effects : because of `tabControl.SelectedIndex = prevIdx;`, `Selector.SelectionChanged` is raised. Moreover the initial tab change won't be really prevented, it'll just be reverted and that means the initial `Selector.SelectionChanged` is also triggered. In the end, the tab change has been properly "prevented" but `Selector.SelectionChanged` is raised twice which is obviously not what we want.

I'm not sure about what's the best way to implement this in WPF, I think the most natural to me would be having a boolean dependency property usable like the above attached property but without the side effects or a PreviewSelectionChanged event that allows me to cancel the change via args... As long as tab changes can be prevented without side effects it's good.