Q:

WPF: Notify nested properties changed

I have a collection of class A, and this class A has a property called Type. Based on the value of Type the background of the corresponding visual item in the view will change. I am implementing INotifyPropertyChanged in the ViewModel, but I do not want for class A to implement INotifyPropertyChanged. Also using ObservableCollection will effect the performance. Now the question is how can I notify the view that the property Type has changed?

A:

Now the question is how can I notify the view that the property Type has changed?

Either implement INotifyPropertyChanged on Type or don't bind directly to a property of Type but to a property of A that wraps the property of Type, e.g.:
private Type _type = new Type();
public string Name
{
    get { return _type.Name; }
    set { _type.Name = value; OnPropertyChanged(); }
}

