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What is INotifyPropertyChanged in Xamarin.Forms?

Updated May 6, 2026

Short answer

INotifyPropertyChanged is an interface used to notify the UI when a property value changes.

Deep explanation

This interface is essential for data binding in Xamarin.Forms. When a property changes in the ViewModel, it triggers the PropertyChanged event, which updates the UI automatically. Without it, UI elements would not reflect changes in data dynamically. It is commonly used in MVVM architecture.

Real-world example

In a profile editing screen, updating the username field immediately reflects in the UI label.

Common mistakes

  • Forgetting to raise PropertyChanged
  • incorrect property names
  • not implementing interface correctly.

Follow-up questions

  • What happens if you don't use INotifyPropertyChanged?
  • Is there a simpler way to implement it?

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