How to listen an abstract method?

Question

In my abstract class can I listen an abstract method and fire an event whenever that method is called? If yes how?

score 3 · Answer 1 · answered Aug 19 '11 at 19:05

3

Abstract or no, you're looking for an Inversion of Control (IoC) framework here, specifically one that lets you do method interception.

I'd look at Unity, or Spring. There are a few others out there.

answered Aug 19 '11 at 19:05

kprobst

16,165
5
32
53

score 3 · Answer 2 · edited Aug 19 '11 at 19:29

3

The best way to do this is as follows:

public abstract class MyClass {

    public void DoOuter() {
        FireEvent();
        DoInner();
    }

    protected abstract void DoInner();
}

When someone wants to call doInner they have to call DoOuter() in order to execute it. To specify functionality you override DoInner(). So FireEvent() is always called before whatever DoInner() functionality is specified... unless it gets called directly by a child class, which you can't really guard against.

edited Aug 19 '11 at 19:29

StriplingWarrior

151,543
27
246
315

answered Aug 19 '11 at 19:25

DJClayworth

26,349
9
53
79

1

This is actually a C# question, so I'm editing the answer a little, but the main idea is correct. – StriplingWarrior Aug 19 '11 at 19:30
D'oh. Thanks, StriplingWarrior. – DJClayworth Aug 19 '11 at 19:38

score 2 · Accepted Answer · edited May 23 '17 at 12:19

2

Not really as an abstract method is always overidden and there is no guarantee that the override call base.Method() to an implementation of it.

Your best bet is to create a virtual method which raises the event and then make all your overrides call base.Method()

If you want to intercept the method call, here is a question about how to do that.

edited May 23 '17 at 12:19

Community

1
1

answered Aug 19 '11 at 19:03

Oskar Kjellin

21,280
10
54
93

How to listen an abstract method?

3 Answers3