OnCreated is called when a file or directory is created in the directory being monitored.
Some common occurrences, such as copying or moving a file or directory, do not correspond directly to an event, but these occurrences do cause events to be raised. When you copy a file or directory, the system raises a Created event in the directory to which the file was copied, if that directory is being watched. If the directory from which you copied was being watched by another instance of FileSystemWatcher, no event would be raised. For example, you create two instances of FileSystemWatcher. FileSystemWatcher1 is set to watch "C:\My Documents", and FileSystemWatcher2 is set to watch "C:\Your Documents". If you copy a file from "My Documents" and paste it into "Your Documents", a Created event will be raised in FileSystemWatcher2, but no event is raised for FileSystemWatcher1. Unlike copying, moving a file or directory raises two events. From the previous example, if you moved a file from "My Documents" to "Your Documents", a Created event would be raised in FileSystemWatcher2 and a Deleted event would be raised in FileSystemWatcher1.
The OnCreated event is raised as soon as a file is created. If a file is being copied or transferred into a watched directory, the OnCreated event will be raised immediately, followed by one or more OnChanged events.
Raising an event invokes the event handler through a delegate. For more information, see Raising an Event.
Notes to Inheritors:
When overriding OnCreated in a derived class, be sure to call the base class's OnCreated method.