Using string constant for notify property changed

Question

I am working with some existing code and trying to figure out the advantage (if any) of using a string constant for the name of a property when implementing INotifyPropertyC

Answer 1

To answer your question (trying to figure out the advantage) : there is an advantage for an observer who know your type and wait for a specific property to change

void Observe(Customer c)
{
    c.PropertyChanged += (s, e) => 
    {
        if (e.PropertyName == Customer.CustomerIdPropertyName)
        {
            MessageBox.Show("New id " + Customer.CustomerId);
        }
    }
}

If you want to go futher :

Typing errors can be avoided using a property selector expression to fill your CustomerIdPropertyName.

You won't need it with nameof keyword (CTP). If you don't have this kind of observer, CalleMemberNameAttribute is the easiest way.