Posted when the Finder is about to unmount a device.
This notification will not be delivered if a volume was forcibly and immediately made unavailable, such as when a FireWire drive is simply unplugged, because there is no chance to deliver it before the volume becomes unavailable.
The notification object is the shared NSWorkspace instance. The userInfo dictionary contains a key @"NSDevicePath" that returns the path where the device was mounted, as a string.
Available in Mac OS X v10.0 and later.
Declaration Syntax Version Information- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)