How to force ListBox to update with INotifyPropertyChanged?

Question

WPF

class MyClassA
{
        private ObservableCollection<AnotherClass> _listCode;
        public ObservableCollection<AnotherClass> ListCode
        {
            get
            {
                return _listCode;
            }
            set
            {
                if (value == _listCode) return;
                _listCode= value;
                OnPropertyChanged("ListCode");
            }
        }

     public void GetList()
     {
           ListCode = ...
     }

        public event PropertyChangedEventHandler PropertyChanged;

        protected virtual void OnPropertyChanged(string propertyName)
        {
            var handler = PropertyChanged;
            if (handler != null) 
                handler(this, new PropertyChangedEventArgs(propertyName));
        }
}

In XAML:

<ListBox ItemsSource="{Binding Path=ListCode}" ItemTemplateSelector="{StaticResource ListTemplateSelector}" />

In a paged class, it is associated with MyClass via the DataContext.
When GetList is executed in the class constructor, the ListBox displays the values, in the case when I call GetList after I updated the ListCode , the ListBox is not updated, although in the debugger I see that the ListCode contains a new element.
OnPropertyChanged doesn't work, why?
UPD And if you add an element to the ListCode and call GetList , then in this case the new element will be displayed in the ListBox. Doesn't work if GetList is called from another class...

Answer 1

Option 1: Your class must inherit INotifyPropertyChanged, only then it will work.
Option 2: ObservableCollection implements INotifyPropertyChanged itself, so to use it your code should look something like this:

class MyClassA
{
      public ObservableCollection<AnotherClass> ListCode { get; private set; };
        
      public MyClassA()
      {
            // ...
            ListCode = new ObservableCollection<AnotherClass>();
      }

      public void GetList()
      {
            ListCode.Clear();
            // ...
            ListCode.Add(new AnotherClass());
      }
}