Enumerators reset index's value

Question

I'm trying to enumerate values of List in different methods (just to send iterator as an argument). It works well, but to my surprise, it's indexes value reset to 1 after it exit the method. Here is an example - can you explain to me how it works and how to solve it?

Thank you so much!

public void SaveHistory(string folder)
{
    using (var iterator = Items.GetEnumerator())
    {
        foreach (var file in _files)
            if (!Proceed(Path.Combine(folder, file.Name), iterator)) //first call
                break;
            //AND HERE my iterator.Index value is 1 again.
        while (Proceed(GetNewFileName(folder), iterator)) { }
     }
}
private bool Proceed(string fileName, IEnumerator<HistoryItemBase> iterator)
{
    var dose = new List<HistoryItemBase>();
    if (iterator.MoveNext())
    {
        while (dose.Count < LogFileItemsCount && iterator.MoveNext())
            dose.Add(iterator.Current);
        //DO Something
    }
    return false; //<- Here iterator.MoveNext() returns false and it's index value is ok
}

[It's a struct](http://stackoverflow.com/questions/3168311/why-do-bcl-collections-use-struct-enumerators-not-classes), [pass it by reference](http://stackoverflow.com/questions/16614704/pass-c-sharp-struct-by-reference) or consider a different design that doesn't require passing around an enumerator altogether. — CodeCaster, Mar 06 '16 at 22:15
Yep.. understand it only after asking a question.. It's a bad idea to work till night :) But thank you so much for your answer! — Artem Makarov, Mar 07 '16 at 08:00

score 0 · Answer 1 · answered Mar 07 '16 at 08:07

0

Well, the answer is very easy - in my case iterator is a struct and all structs passes to methods by value, not reference.. And in my case I can't just add a ref word to a parameter, because I'm working with using- statement.

Thank you!

answered Mar 07 '16 at 08:07

Artem Makarov

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Enumerators reset index's value

1 Answers1