Question

Say I have a class that implements IEnumerable<T>. It currently uses the yield keyword in the GetEnumerator() method. But now I need to do a bit more, for example I would like to clean up after myself. To do this, unless I have overlooked anything, I need to implement the IEnumerator<T> interface. But where would you say I should do that?

Should the class itself implement it and GetEnumerator() return this? Or would it be better to hide it in a private class? Or should it maybe just be an entirely different class? What are some common practices to this?

Answer 1

If all you need to do is clean up some resources when the enumerator is disposed of, like at the end of a foreach loop, then you can do that with what you have, just add a try/finally block to your iterator method.

Like this:

public IEnumerator<T> GetEnumerator()
{
    try
    {
        // your iterator code here
    }
    finally
    {
        // cleanup code here
    }
}

That’s all there is to it.