在分配给活动期间是否复制了代理?

public delegate void DirListEvent<T>(T dirItem);

void Main()
{
    DirListEvent<string> printFilename = s => {
        Console.WriteLine (s);
    };

    var obj = new DirectoryLister();

    obj.FileRetrieved += printFilename;
    obj.FileRetrieved += printFilename;

    obj.GetDirListing();
}

public class DirectoryLister {

    public event DirListEvent<string> FileRetrieved;


    public DirectoryLister() {
        FileRetrieved += delegate {};
    }

    public void GetDirListing() {

        foreach (var file in Directory.GetFiles(@"C:\"))
        {
            FileRetrieved(file);
        }
    }
}