Log who subscribs to a event

It it possible to retrive who is subscribing to a event in C#?

example

class MyClass
{
  public string Name { get; set; } 
}

class Syncronizer
{
  public delegate void SynchronizatonEventHandler(MyClass myClass);
  public event SynchronizatonEventHandler OnSyncFinished;
}

If i have something like that is it possible for me to see/use the myClass.Name string and use it for logging when the event is subscribed to?

What i开发者_高级运维 want to accomplish is that i want to log every subscribe and unsubscribe from my Syncronizer class.

---

You can do the following:

class MyClass
{
    public string Name { get; set; }
}

class Syncronizer
{
    public delegate void SynchronizatonEventHandler(MyClass myClass);
    internal event SynchronizatonEventHandler _onSyncFinished;

    public event SynchronizatonEventHandler OnSyncFinished
    {
        add
        {
            // Perform some code before the subscription.
            // Add the event.
            _onSyncFinished += value;
            // Perform some code after the subscription;
        }
        remove
        {
            // Perform some code before the subscription.
            // Remove the event.
            _onSyncFinished -= value;
            // Peroform some code after the subscription.
        }
    }
}

---

Here's a working example:

class Syncronizer
{
    public delegate void SynchronizatonEventHandler(MyClass myClass);
    private event SynchronizatonEventHandler onSyncFinished;
    public event SynchronizatonEventHandler OnSyncFinished
    {
        add
        {
            var method = new StackTrace().GetFrame(1).GetMethod();
            Console.WriteLine("{0}.{1} subscribing", method.ReflectedType.Name, method.Name);
            onSyncFinished += value;
        }
        remove
        {
            var method = new StackTrace().GetFrame(1).GetMethod();
            Console.WriteLine("{0}.{1} unsubscribing", method.ReflectedType.Name, method.Name);
            onSyncFinished -= value;
        }
    }
}

Note that you can not log myClass.Name, since that doesn't exist in the add and remove procedures. I have it logging (to Console.WriteLine) the class and method that subscribed to the event, which is, I think, what you were after.

---

You need to create an explicit event with your own accessors:

public event SynchronizatonEventHandler OnSyncFinished {
    add { ... }
    remove { ... }
}

add and remove take a value parameter containing the delegate instance being removed from or added to the event.
For logging purposes, you can get the Method and Target properties of the instance.

---

Sth. like this should solve your issue:

private event SynchronizatonEventHandler m_OnSyncFinished;

public event SynchronizatonEventHandler OnSyncFinished
{
  add
  {
    // Custom code could be added here...
    m_OnSyncFinished += value;
  }
  remove
  {
    // Custom code could be added here...
    m_OnSyncFinished -= value;
  }
}