Retrieves the total (aggregated) number of unread items.
[ count = ] FeedFolder.TotalUnreadItemCount
count Integer that receives the total number of items.
The property is read-only. The property has no default value.
The value returned from TotalUnreadItemCount is an aggregate of all the feeds in the current folder and its subfolders.
This property returns a cached value and does not require access to any feed files.