C#: Where should you place event handler delegates?

Question

I have this class:

public class GenericEventArgs<T> : EventArgs
{
    public GenericEventArgs() : this(default(T)) {}
    public GenericEventArgs(T value) { Value = value; }
    public T Value { get; private set; }
}

And this event handler delegate for it:

public delegate void GenericEventHandler<T>(object sender, GenericEventArgs<T> e);

I currently have these in the same file together in a namespace. Is that considered bad/messy/etc.? Cause, in general I would say that each file should contain only one class. So to have it clean I would prefer to have the GenericEventArgs class in the file alone. But then I have this GenericEventHandler<T> delegate that I am not sure where I should place. Should it have its own file? With just... that one line kind of? (and the namespace of course)

How do you usually do this?

Answer 1

Any reason for not using EventHandler<TEventArgs>? I thought there was an equivalent EventArgs<T> but I can't see it at the moment... Anyway, I'd put GenericEventArgs in GenericEventArgs.cs

Personally, when I want to introduce my own delegate types (which is increasingly rare, to be honest) I create a Delegates.cs file with all the appropriate delegates for the namespace in. Then I know where to find them without having a file for a single declaration.