Adding Callbacks on Undo and Redo

Caution

Undo/Redo was deprecated in PostSharp 2026.0 and will not be maintained. The API will be removed in the future.

You may run into situations where you will want to execute some code before or after an object is being modified by an Undo or Redo operation. This capability is provided through the IRecordableCallback interface.

In the following example, we output a message each time an undo or redo operation executes.

Full screen

[Recordable]
public class Invoice : IRecordableCallback
{
  public void OnReplaying(ReplayKind kind, ReplayContext context)
  {
      if (kind == ReplayKind.Redo) {
           Console.WriteLine("I will now redo a previously undone change to the shipping date.");
      }
  }
  
  public void OnReplayed(ReplayKind kind, ReplayContext context)
  {
      if (kind == ReplayKind.Undo) {
           Console.WriteLine("A change to the shipping date is now undone.");
      }
  }
  
  public DateTime ShippingDate { get; set; }   
}

For more information, see the reference documentation for the IRecordableCallback interface.