A collection of alternatives to the System.IO.FileSystemWatcher class.

As you can see with a quick google search - FilesystemWatcher is far from perfect. In fact, it is problematic enough that Microsoft gave it an "Error" event so you can react when it encounters a problem. To put it in simple words, there are 2 main issues with it:

1. It misses file changes when under heavy load, rendering it unreliable.
2. It stops working under certain circumstances.

The alternatives offered are:

1. FileSystemPoller - Periodicly polls for file system changes.
2. FileSystemRefreshableWatcher - A watcher wrapper. Allows the user to restart a broken watcher.
3. FileSystemAutoRefreshingWatcher - A watcher wrapper. Automatically restarts a watcher if it breaks.
4. FileSystemOverseer - A watcher wrapper. Automatically restarts a watcher if it breaks and uses a backup poller for increased reliability.

The table over here shows you the upsides and downsides of FileSystemWatcher and my alternatives. Choose the one that fits your requirements.

All alternatives in this library implements an interface called "IFileSystemWatcher" It defines methods and events corresponding to the ones in System.IO.FileSystemWatcher. If your project is already utilizing FileSytemWatcher you can simply change this:

FileSystemWatcher sysMonitor = new FileSystemWatcher(@"C:\");

To any of those:

IFileSystemWatcher sysMonitor = new FileSystemRefreshableWatcher(@"C:\");
IFileSystemWatcher sysMonitor = new FileSystemAutoRefreshingWatcher(@"C:\");
IFileSystemWatcher sysMonitor = new FileSystemPoller(pollingInterval: 500,path: @"C:\");
IFileSystemWatcher sysMonitor = new FileSystemOverseer(pollingInterval: 500, path: @"C:\");

Then use Created/Deleted/Renamed/Changed events as you would with FileSystemWatcher.

Icon: Binoculars designed by Gregor Crešnar from The Noun Project