Use a FileSystemWatcher like below to create a WatcherCreated Event().
I used this to create a Windows Service that watches a Network folder and then emails a specified group on arrival of new files.
// Declare a new FILESYSTEMWATCHER
protected FileSystemWatcher watcher;
string pathToFolder = @"YourDesired Path Here";
// Initialize the New FILESYSTEMWATCHER
watcher = new FileSystemWatcher {Path = pathToFolder, IncludeSubdirectories = true, Filter = "*.*"};
watcher.EnableRaisingEvents = true;
watcher.Created += new FileSystemEventHandler(WatcherCreated);
void WatcherCreated(object source , FileSystemEventArgs e)
{
//Code goes here for when a new file is detected
}