Question

If I do the following:

public class Test
{
    public static void Main()
    {
        List<Person> persons = new List<Person> { new Person() };

        persons[0].Sneezing += new EventHandler(Person_Sneezing);

        persons = null;
    }

    public static void Person_Sneezing(object sender, EventArgs e)
    {
        (sender as Person).CoverFace();
    }
}

Does the person that was in person[0] still exists in memory because it’s Sneezing delegate has a reference to the Person_Sneezing method or does it get collected by the GC?

Answer 1

This will be collected by the GC. To be kept in memory an object must be referenced directly or indirectly by …

1. A value on the stack
2. A value rooted in a strong GC handle
3. A corner case or two I’m not thinking of at the moment

This is not true for the object at persons[0]. So it will be collected.

That is of course assuming the constructor for Person() doesn’t do anything funny like add itself to ThreadLocalStorage.