When a form is closed, it gets a useful argument in its FormClosed event, CloseReason. However our app runs with only a tray icon and no windows open most of the time. When it exits, I'd like to log the reason it exited - in particular, knowing CloseReason.WindowsShutDown and CloseReason.TaskManagerClosing would be useful.
Is there any way to check for the above after Application.Run returns, in the absence of any Form instances?
There is no built-in way of doing this, but you could always do your own.
The easiest would probably be to add a static property to your Program class where you assign the CloseReason you get in the FormClosed event. This could then be read in your code at a later point.
Alternatively you could create your own class that derives from ApplicationContext and handle the FormClosed event there. That might be a cleaner approach, but it would also be more cumbersome to set up.