内存泄漏和局部变量

我有以下方法(在prism的RegionAdapter中):

protected override void Adapt(IRegion region, DocumentPane regionTarget)
{
    region.Views.CollectionChanged += delegate(object sender, NotifyCollectionChangedEventArgs e)
    {
        OnViewsCollectionChanged(sender, e, region, regionTarget);
    };
}

我的问题是，通过这种方式订阅事件，我有内存泄漏。但是region和regionTarget参数是Adapt的局部变量。

我试着查找这个，看看是否有人以不同的方式处理场景，但MSDN和mvp都使用这种泄漏的方法…

我应该如何处理它，以便以后可以取消订阅该事件?

编辑:

上面的代码只是一个例子，我认为它清楚地说明了问题。
泄漏内存的实际代码如下:

private void OnViewsCollectionChanged(object sender, 
    NotifyCollectionChangedEventArgs e, IRegion region, 
    DocumentPane regionTarget)
{
    if (e.Action == NotifyCollectionChangedAction.Add)
    {
        //Add content panes for each associated view.
        foreach (object item in e.NewItems)
        {
            UIElement view = item as UIElement;
            if (view != null)
            {
                DockableContent newContentPane = new DockableContent();
                newContentPane.IsCloseable = true;
                newContentPane.HideOnClose = false;
                ScrollViewer sViewer = new ScrollViewer()
                {
                    Content = item,
                    HorizontalScrollBarVisibility = ScrollBarVisibility.Auto,
                    VerticalScrollBarVisibility = ScrollBarVisibility.Auto
                };
                newContentPane.Content = sViewer;
                //When contentPane is closed remove the associated region
                // (MEMORY LEAK)
                newContentPane.Closed += (contentPaneSender, args) =>
                {
                    DockableContent docker =
                        contentPaneSender as DockableContent;
                    ScrollViewer scroller = docker.Content as ScrollViewer;
                    region.Remove(scroller.Content);
                    IDisposable dispView = scroller.Content as IDisposable;
                    if (dispView != null) dispView.Dispose();
                    scroller.Content = null;
                };
                regionTarget.Items.Add(newContentPane);
                newContentPane.Activate();
            }
        }
    }
}

谢谢,

巴布。

   private Region _region;
   DocumentPane _regionTarget
   protected override void Adapt(IRegion region, DocumentPane regionTarget)
    {
        _region = region;
        _regionTarget = regionTarget;
        region.Views.CollectionChanged += OnCollectionChanged;
    }
    private void OnCollectionChanged (object sender, NotifyCollectionChangedEventArgs e) 
    {
        OnViewsCollectionChanged(sender, e, _region, _regionTarget);
    }
    ...
    private void Unsubscribe() 
    {
      _region.Views.CollectionChanged -= OnCollectionChanged;
    }