How can I expose only a fragment of IList<>?

Question

I have a class property exposing an internal IList<> through

System.Collections.ObjectModel.ReadOnlyCollection<>

How can I pass a part of this ReadOnlyCollection<> without copying elements into a new array (I need a live view, and the target device is short on memory)? I'm targetting Compact Framework 2.0.

Answer 1

Try a method that returns an enumeration using yield:

IEnumerable<T> FilterCollection<T>( ReadOnlyCollection<T> input ) {
    foreach ( T item in input )
        if (  /* criterion is met */ )
            yield return item;
}