Usage of Entry via binding: How to get notified if text is finally changed, not on each character.

I have an Entry control whose Text property is bound to my ViewModel. But the setter of the property in the ViewModel is called on each character change (equivalent to UpdateSourceTrigger = "PropertyChanged" in WPF) but I want to get the complete text when the input is finished (virtual keyboard closed or another element is tapped).

The reason why I want this is because I have to send the text of the Entry via an open WebSocket connection and I don't want to send each change, only when the input is done.

How can I achieve that?

Regards,
Christian