如何在我的代码中处置 IDisposable

在我一直在研究的以下类的CreateRegistryObservable方法中，我无法弄清楚如何干净地处理下一行分配的IDisposable。这样做的问题是，我从分配给onComplete委托的Action中引用它，该委托使用 {null} 初始化捕获声明的数组变量，并且在调用此操作时不会反映通过调用 Schedule() 在最后返回的内容的赋值。如何干净地处置调度程序？

scheduler[0] = Scheduler.CurrentThread.Schedule(iterator);
public class RegistryKeyMonitor<T> : IObservable<T>
{
    private readonly RegistryKey _registryKey;
    private readonly string _name;
    private readonly TimeSpan _timeSpan;
    private readonly ILog _logger = LogManager.GetLogger("RegistryKeyMonitor");
    public RegistryKeyMonitor(RegistryKey registryKey, string name, TimeSpan timeSpan)
    {
        _registryKey = registryKey;
        _name = name;
        _timeSpan = timeSpan;
    }
    public IDisposable Subscribe(IObserver<T> observer)
    {
        var sub =CreateRegistryObservable(_registryKey, _name, _timeSpan)
            //.Catch(Observable.Empty<object>())
            .Where(obj => obj != null)
            .Cast<T>();
        return sub.Subscribe(observer);
    }
    private IObservable<object> CreateValueChangeObservable(RegistryKey registryKey, string name, object initialValue, 
        TimeSpan timeSpan, CancellationToken token)
    {
        return Observable.Create<object>(o =>
            {
                var scheduler = Scheduler.Immediate;
                Action<object, Action<object, TimeSpan>> iterator = (current, self) =>
                    {
                        try
                        {
                            if (token.IsCancellationRequested) 
                            {   
                                o.OnCompleted();
                                return;
                            }
                            var value = registryKey.GetValue(name);
                            _logger.DebugFormat("{0} == registryKey.GetValue(name)", value);
                            if (current == null && value != null ||
                                current != null && !current.Equals(value))
                            {
                                _logger.DebugFormat("passing data {0}", value);
                                o.OnNext(value);
                            }
                            else
                                self(value, timeSpan);
                        }
                        catch (Exception e)
                        {
                            o.OnError(e);
                        }
                    };
                return scheduler.Schedule(initialValue, timeSpan, iterator);
            });
    }
    public IObservable<object> CreateRegistryObservable(RegistryKey registryKey, string name, TimeSpan timeSpan)
    {
        return Observable.Create<object>(o =>
            {
                var cancel = new CancellationDisposable();
                return new CompositeDisposable(cancel, 
                    NewThreadScheduler.Default.Schedule(() =>
                        {
                            IDisposable[] scheduler = {null};
                            var currentStateSubscription = new SerialDisposable();
                            object currentValue = null;
                            Action<Action> iterator = self =>
                                currentStateSubscription.Disposable =
                                CreateValueChangeObservable(registryKey, name, currentValue,
                                                            timeSpan, cancel.Token)
                                    .Subscribe(value =>
                                    {
                                        currentValue = value;
                                        self();
                                        o.OnNext(value);
                                    },
                                    o.OnError, 
                                    ()=> {
                                            currentStateSubscription.Dispose();
                                            scheduler[0].Dispose();
                                    }
                                    );
                            scheduler[0] = Scheduler.CurrentThread.Schedule(iterator);
                    }));
            });
    }
}

public IObservable<object> CreateRegistryObservable(RegistryKey registryKey, string name, TimeSpan timeSpan)
    {
        return Observable.Create<object>(o =>
            {
                var cancel = new CancellationDisposable();
                var currentStateSubscription = new SerialDisposable();
                object currentValue = null;
                return new CompositeDisposable(cancel, NewThreadScheduler.Default.Schedule(
                    self => currentStateSubscription.Disposable =
                        CreateValueChangeObservable(registryKey, name, currentValue,
                                                    timeSpan, cancel.Token)
                            .Subscribe(value =>
                            {
                                currentValue = value;
                                self();
                                o.OnNext(value);
                            },
                            o.OnError, 
                            currentStateSubscription.Dispose
                            )
                    ));
            });
    }