Keiki, my OptusNet Usage Meter, is designed to sit in the notification area (or system tray, if you prefer) and behave similarly to the default system ‘applets’ (Volume/Network/Action Centre/Power). That is, the application becomes visible with a single left click on the notify (tray) icon, and is hidden again when focus is lost.
I have recently started to refactor Keiki’s code, as I have learnt a lot about WPF since I first wrote the application. While refactoring I’ve also tried to polish a few rough edges: one of these is the main window’s resize behaviour. The Windows 7 (and Vista before it) tray applications (excuse the ever-changing terminology) have no title bar and are not resizable. It turns out that this window style isn’t trivial to implement with WPF.
Updated: improved code to focus application when border is clicked.