Live binding property change for textbox [duplicate]

This question already has answers here: TextBox and default Button binding does update too late (3 answers) Closed 5 years ago.

I have a TextBox control on my form that is bound to a property in my view model. The current behaviour works in a way that the view model will only get notified that the text in the TextBox was modified after the control loses focus.

How can I inform my view model whenever the TextBox开发者_开发问答 changes state in real time? This is attached to a property in my view model that determines if the save button is enabled. So if I type one letter into this TextBox right away my save button should be enabled without having to lose focus.

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Change UpdateSourceTrigger on the binding to PropertyChanged.