System.Windows.Data.DataList.DataRange.IEnumerator C# (CSharp) Method

            bool IEnumerator.MoveNext()
            {
                if (_version != _owner._version) {
                    throw new InvalidOperationException("This enumerator is no longer valid.");
                }

                if (_index == -1) {
                    _index = _startIndex;
                }
                else {
                    _index++;
                    if (_index > _endIndex) {
                        _index = -1;
                    }
                }

                if (_index >= _owner._snapShot.Count) {
                    _index = -1;
                }
                return (_index != -1);
            }