How to know whether property value change has started or ended at PropertyChanged method on using "UpdateSourceTrigger = PropertyChanged"?

Hi,

We have a scenario where we need to use UpdateSourceTrigger = PropertyChanged, because we need to show the changing text as user keeps typing in same control. Because of this, i am aware that the PropertyChanged will be triggered on every text change.

Is there a chance to know, if there is any possibility to identify that the COMPLETE property value of that control has changed while losing focus at PropertyChanged method call in set property?

Thank you in advance!

Regards

-Babu