.NET (Core and Framework)

public partial class Charge
    {
        public Charge()
        {
            this.ActivityReference.AssociationChanged += new System.ComponentModel.CollectionChangeEventHandler(ActivityReference_AssociationChanged);
        }

        void ActivityReference_AssociationChanged(object sender, System.ComponentModel.CollectionChangeEventArgs e)
        {
            if ((e.Action == System.ComponentModel.CollectionChangeAction.Remove))
                OnPropertyChanging("Activity");
            else
                OnPropertyChanged("Activity");
        }
    }

Public Function NumberOfLetters(s as String) as Integer
  For idx As Integer = 0 To s.Length - 1
	If Not Char.IsLetter(s(idx)) Then Return idx - 1
  Next
  Return s.Length
End Function

.OrderBy(Function(key) key == "ORD" ? 1000 : int.Parse(key.SubString(3))