Subscribing to events in a separate class

Question

I am having a bit of trouble subscribing to an event I have created. The event itself is in its own class and I want to be able to subscribe to it from a separate class in a separate project. I am able to subscribe to it from the class in which it is created - but when I try to subscribe from a different class in a different project nothing happens.

Could someone give me a few pointers on how I can work through this at all? I have been all over Google trying to find a solution but to no avail :(.

Would you please post some of your code? – Andrew Hare Jun 19 '09 at 17:27 — Andrew Hare, Jun 19 '09 at 17:27
Obvious question first: Is the event public? – Scott Arrington Jun 19 '09 at 17:29 — Scott Arrington, Jun 19 '09 at 17:29

score 6 · Answer 1 · answered Jun 19 '09 at 17:31

Here is a simple example of an event I have created and subscribed to:

using System;

class Program
{
    static void Main()
    {
        Foo foo = new Foo();
        foo.Fooing += () => Console.WriteLine("Foo foo'd");

        foo.PleaseRaiseFoo();
    }
}

class Foo
{
    public event Action Fooing;

    protected void OnFooing()
    {
        if (this.Fooing != null)
            this.Fooing();
    }

    public void PleaseRaiseFoo()
    {
        this.OnFooing();
    }
}

Hopefully this ought to be able to point you in the right direction. The main things to check in your code:

Is your event marked as public?
Do you ever raise the event? (e.g. this.Fooing())

score 1 · Answer 2 · answered Jun 19 '09 at 17:43

I just tried your sample code with an EventHandler delegate instead of Action (since I couldn't find a non-generic Action delegate in the System namespace)

The code below works just as you'd expect: It outputs "Foo foo'd".

Maybe it's the Action delegate, though I find that somewhat weird.

class Program
{
    static void Main()
    {
        Foo foo = new Foo();
        foo.Fooing += (object o, EventArgs e) => Console.WriteLine("Foo foo'd");

        foo.PleaseRaiseFoo();
    }
}

class Foo
{
    public event EventHandler Fooing;

    protected void OnFooing()
    {
        if (this.Fooing != null)
            this.Fooing(null, null);
    }

    public void PleaseRaiseFoo()
    {
        this.OnFooing();
    }
}

The sample code was posted by Andrew, not the OP. Andrews code should work as is. — Brandon, Jun 19 '09 at 17:49
Oh my, I'm terribly sorry - didn't mean to steal the answer :-( — Steffen, Jun 20 '09 at 09:56

score 0 · Answer 3 · answered Jun 19 '09 at 17:32

0

Have you tried this?

MyInstanceOfMyClass.MyEvent += new EventHandler(MyDelegate);
protected void MyDelegate(object sender, EventArgs e) { ... }

answered Jun 19 '09 at 17:32

maxbeaudoin

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score 0 · Answer 4 · answered Jun 19 '09 at 18:03

0

You noted that your class is in a different project, can you see the event class (or any other class in that project)? Perhaps you haven't referenced your other project properly.

answered Jun 19 '09 at 18:03

Nathan Koop

24,803
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Subscribing to events in a separate class

4 Answers4