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POType to track the position of a list using IEnumerable
 

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    <p>I’m trying to develop a type to track the current iteration position with a list.</p> <p>I ideally want to used it with a foreach loop using the IEnumerable interface but the interface has no start/stop events or method to hooking to reset the count. </p> <p>Currently I have created a GetNext( ) method which return the next value in the list and increments a count by 1.</p> <p>Does anyone know I can achieve the same functionality using IEnumerable so I can use the type with a foreach loop?</p> <p>So for example; imagine a list contains 10 items. One method could iterate an instance of the type to position 4 then method two would iterate the same instance starting at position 5 to 6 then method 3 would iterate the remainng from position 7 to 10 – so the type instance tracks the current position.</p> <p>Any ideas are greatly appreciated (code shown below) . Thanks</p> <pre><code>public sealed class PositionTracker&lt;T&gt; : IEnumerable { private readonly object _syncLock = new object(); private readonly IList&lt;T&gt; _list = new List&lt;T&gt;(); private int _current; public PositionTracker(IList&lt;T&gt; list) { _list = list; } public T GetCurrent() { lock (_syncLock) { return _list[_current]; } } public T GetNext() { lock (_syncLock) { T t = GetCurrent(); if (_current &lt; _list.Count - 1) { _current++; } return t; } } public IEnumerator&lt;T&gt; GetEnumerator() { lock (_syncLock) { return _list.GetEnumerator(); } } IEnumerator IEnumerable.GetEnumerator() { return GetEnumerator(); } public void Reset() { lock (_syncLock) { _current = 0; } } public int Count { get { lock (_syncLock) { return _list.Count; } } } } [TestFixture] public class PositionTrackerTests { [Test] public void Position_CurrentPosition_Test() { List&lt;string&gt; list = new List&lt;string&gt;(new string[] { "A", "B", "C", "D" }); PositionTracker&lt;string&gt; positionTracker = new PositionTracker&lt;string&gt;(list); Assert.IsTrue(positionTracker.GetNext().Equals("A")); Assert.IsTrue(positionTracker.GetNext().Equals("B")); Assert.IsTrue(positionTracker.GetNext().Equals("C")); Assert.IsTrue(positionTracker.GetNext().Equals("D")); } } </code></pre>
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