Why is my FileSystem Watcher not firing events?

Question

I create a FileSystemWatcher on a separate thread to monitor a directory for changes. None of my events fire when I add a new file or copy a new file into the directory that I am trying to monitor. I've used the FileSystemWatcher class successfully in Windows Forms apps, so I am guessing I am missing something simple.

public partial class MainWindow : Window
{

    System.IO.FileSystemWatcher watcher;
    public MainWindow()
    {
        InitializeComponent();
        System.Threading.Thread t1 = new System.Threading.Thread(MonitorDir);
        t1.IsBackground = true;
        t1.Start();
    }

    private void MonitorDir()
    {

        watcher = new System.IO.FileSystemWatcher("C:\\Temp","*.*");
        watcher.Created += Watcher_Created;
        watcher.Disposed += Watcher_Disposed;
        watcher.Error += Watcher_Error;
        watcher.Changed += Watcher_Changed;
        while (true)
        {

        }
    }

    private void Watcher_Changed(object sender, System.IO.FileSystemEventArgs e)
    {
        throw new NotImplementedException();
    }

    private void Watcher_Error(object sender, System.IO.ErrorEventArgs e)
    {
        throw new NotImplementedException();
    }

    private void Watcher_Disposed(object sender, EventArgs e)
    {
        throw new NotImplementedException();
    }

    private void Watcher_Created(object sender, System.IO.FileSystemEventArgs e)
    {
        throw new NotImplementedException();
    }
}

Answer 1

You need to set its EnableRaisingEvents property to true (it's false by default), otherwise it won't raise any events.

watcher.EnableRaisingEvents = true;