How to catch the moment of selecting a tab?

Question

WPF

I need to somehow catch the moment when the TabControl's tab becomes active. (TabItem.IsSelected) And the usual bind will not be enough here. I need exactly the moment when the user opened the tab. I am writing a chat and it will be as if there were messages not read, but read. So what's the best way to catch it? The only thing that comes to mind is to bind the ViewModel to IsSelected and make an infinite loop in a parallel thread that will check this property and perform the necessary actions when it changes. (well, or just call the handler function) Will this option go or are there any better thoughts?

Answer 1

For "your" tab, rewrite: protected override void OnVisibleChanged(EventArgs e), and mark if visible: if (this.Visble)... - or do the same for the VisibleChanged event, if you have not created your own class for the tab.

Answer 2

TabControl has a SelectionChanged event.
If this is not enough, and you need to check for focus changes, then you also need to catch the focus.
Sergey Ronin wrote everything above.