c# - Outlook 2013 和 Outlook 加载项::MAPIFolder Events_12_Event.BeforeReMove 未触发？

Question

我正在尝试实现 Adrian Brown 非常好的 Outlook Add-In code 3 次中有 2 次有效。 ItemAdd 和 ItemChange 事件按预期触发，但 MAPIFolderEvents_12_Event.BeforeItemMove 的事件处理程序似乎没有做任何事情 - 我没有甚至在事件处理程序的第一行命中断点。

更多清晰代码

这是 CalendarMonitor 类；它监视文件夹的 Items 集合上的 ItemAdd、ItemChange 事件，以及 MAPIFolder 上的 BeforeItemMove:

public class CalendarMonitor
{
    private Explorer _explorer;
    private List<string> _folderPaths;
    private List<MAPIFolder> _calendarFolders;
    private List<Items> _calendarItems;
    private MAPIFolder _deletedItemsFolder;

    public event EventHandler<EventArgs<AppointmentItem>> AppointmentAdded;
    public event EventHandler<EventArgs<AppointmentItem>> AppointmentModified;
    public event EventHandler<CancelEventArgs<AppointmentItem>> AppointmentDeleting;

    public CalendarMonitor(Explorer explorer)
    {
        _folderPaths = new List<string>();
        _calendarFolders = new List<MAPIFolder>();
        _calendarItems = new List<Items>();

        _explorer = explorer;
        _explorer.BeforeFolderSwitch += Explorer_BeforeFolderSwitch;

        var session = _explorer.Session;
        try
        {
            _deletedItemsFolder = session.GetDefaultFolder(OlDefaultFolders.olFolderDeletedItems);
            HookupDefaultCalendarEvents(session);
        }
        finally
        {
            Marshal.ReleaseComObject(session);
            session = null;
        }
    }

    private void HookupDefaultCalendarEvents(_NameSpace session)
    {
        var folder = session.GetDefaultFolder(OlDefaultFolders.olFolderCalendar);
        if (folder == null) return;

        try
        {
            HookupCalendarEvents(folder);
        }
        finally
        {
            Marshal.ReleaseComObject(folder);
            folder = null;
        }
    }

    private void Explorer_BeforeFolderSwitch(object obj, ref bool cancel)
    {
        var folder = (obj as MAPIFolder);
        if (folder == null) return;

        try
        {
            // Hookup events to any other Calendar folder opened.
            if (folder.DefaultItemType == OlItemType.olAppointmentItem)
                HookupCalendarEvents(folder);
        }
        finally
        {
            Marshal.ReleaseComObject(folder);
            folder = null;
        }
    }

    private void HookupCalendarEvents(MAPIFolder calendarFolder)
    {
        if (calendarFolder.DefaultItemType != OlItemType.olAppointmentItem)
        {
            throw new ArgumentException("The MAPIFolder must use AppointmentItems as the default type.");
        }

        // Ignore other user's calendars.
        if (_folderPaths.Contains(calendarFolder.FolderPath) || (!IsUsersCalendar(calendarFolder))) return;

        var items = calendarFolder.Items;

        // Store folder path to prevent repeating listeners
        _folderPaths.Add(calendarFolder.FolderPath);

        // Store a reference to the folder & items to prevent garbage collection
        _calendarFolders.Add(calendarFolder);
        _calendarItems.Add(items);

        // Add listeners
        ((MAPIFolderEvents_12_Event)calendarFolder).BeforeItemMove += Calendar_BeforeItemMove;
        items.ItemChange += CalendarItems_ItemChange;
        items.ItemAdd += CalendarItems_ItemAdd;
    }

    private void CalendarItems_ItemAdd(object obj)
    {
        var appointment = (obj as AppointmentItem);
        if (appointment == null) return;

        try
        {
            if (AppointmentAdded != null)
                AppointmentAdded(this, new EventArgs<AppointmentItem>(appointment));
        }
        finally
        {
            Marshal.ReleaseComObject(appointment);
            appointment = null;
        }
    }

    private void CalendarItems_ItemChange(object obj)
    {
        var appointment = (obj as AppointmentItem);
        if (appointment == null) return;

        try
        {
            if (AppointmentModified != null)
                AppointmentModified(this, new EventArgs<AppointmentItem>(appointment));
        }
        finally
        {
            Marshal.ReleaseComObject(appointment);
            appointment = null;
        }
    }

    private void Calendar_BeforeItemMove(object obj, MAPIFolder moveToFolder, ref bool cancel)
    { 
        if ((moveToFolder != null) && (!IsDeletedItemsFolder(moveToFolder))) return;

        var appointment = (obj as AppointmentItem);
        if (appointment == null) return;

        try
        {
            if (AppointmentDeleting == null) return;

            // Listeners to the AppointmentDeleting event can cancel the move operation if moving
            // to the deleted items folder.
            var args = new CancelEventArgs<AppointmentItem>(appointment);
            AppointmentDeleting(this, args);
            cancel = args.Cancel;
        }
        finally
        {
            Marshal.ReleaseComObject(appointment);
            appointment = null;
        }
    }

    private bool IsUsersCalendar(MAPIFolder folder)
    {
        // This is based purely on my observations so far - a better way?
        return (folder.Store != null);
    }

    private bool IsDeletedItemsFolder(MAPIFolder folder)
    {
        return (folder.EntryID == _deletedItemsFolder.EntryID);
    }

    public AppointmentItem Item { get; set; }
}

新信息:

我已经完成了一些额外的“故障排除”并提供了更多信息:一时兴起，我在 Outlook 中创建了一个新日历(在调试时)，你看 BeforeItemMove 事件就像我希望在删除新日历中的约会时可以，但它在原来的日历中仍然不起作用。

如果我退出调试 session 并重新启动，日历的事件都不会按预期运行，尽管之前工作正常。任何新日历的 BeforeItemMove 事件都可以正常工作，直到我关闭 Outlook - 然后它又回到无响应状态。

我希望这些额外的信息能为比我聪明的人提供见解。非常感谢任何帮助。

Answer 1

calFolder 变量必须在全局/类级别声明以避免被垃圾收集器释放。