当调用派生类中的方法时，基类是否有可能获得通知？

Question

Consider the following little design:

public class Parent
{
  public event EventHandler ParentWentOut;
  public virtual void GoToWork()
  {
     ParentWentOut();
  }
}

public class Mother : Parent
{
   public override void GoToWork()
   {
     // Do some stuff here
     base.GoToWork(); // <- I don't want to write this in any derived class. 
                      //    I want base class's method to be automatically called.
   }
}

Is there any mechanism to make Parent.GoToWork method implicitly and automatically be called whenever this method finishes in overridden version of the descendants (here Mother class) ?

If there is any other language than C# able to do so, I'll be very thankful to know.

Answer 1

You can try to implement something like this

public class Parent
{
   public event EventHandler ParentWentOut;
   public void GoToWork()
   {
     BeforeParentWentOut();
     ParentWentOut();
     AfterParentWentOut();         
   }

   protected virtual void BeforeParentWentOut()
   {
      // Dont do anything, you can even make it abstract if it suits you
   }

   protected virtual void AfterParentWentOut()
   {
      // Dont do anything, you can even make it abstract if it suits you
   }
}



public class Mother : Parent
{
   protected override void BeforeParentWentOut()
   {
      // Do some stuff here
   }
}

Also you can subscribe to your own event on the Mother class and react to that.

EDIT: update for protected, added before/after methods to handle when to add code to the parent implementation

Answer 2

I would suggest having two methods - one for the public API and one for the internal functioning of the method.

public class Parent
{
  public event EventHandler ParentWentOut;
  public void GoToWork()
  {
     GoToWorkOverride();
     ParentWentOut();
  }

  protected virtual void GoToWorkOverride()
  {}
}

public class Mother : Parent
{
   protected override void GoToWorkOverride()
   {
       // Do some stuff here
   }
}

Answer 3

So, far the only way to access the base class is through the base keyword which some how hold a reference to base class which is initialized by calling its constructor.

Thus your answer is no.