Passing INotifyDataErrorInfo Errors into Nested User Controls in WPF

To pass INotifyDataErrorInfo validation errors into nested user controls in WPF, ensure that your ViewModel implements INotifyDataErrorInfo and binds to the nested control’s DataContext. Use Binding.Validation.Errors in XAML or propagate errors via Validation.Errors in DependencyProperties.

Example:

Implement INotifyDataErrorInfo in the parent ViewModel. Bind DataContext of the nested UserControl to the relevant property. Use ValidatesOnNotifyDataErrors=True in bindings. If issues persist, consider Command Binding or explicit error propagation. Let me know if you need more details!