Question

Consider the following code in a class called Worker

    FileSystemWatcher watcher = new FileSystemWatcher();
    public void Run()
    {
        watcher.Path = @"c:\queue";
        watcher.Created += new FileSystemEventHandler(watcher_Created);
        watcher.EnableRaisingEvents = true;
    }

Now here’s what I would like to do wih the Worker, but obviouly this doesn’t fly.

        Worker worker = new Worker();
        Thread thread = new Thread(worker.Run);
        thread.Start();
        Console.ReadLine(); // something else more interesting would go here.

The reason being that the Run method ends rather than going into some sort of event loop. How do I get an event loop going. (I think I”m looking for something like Application.Run)

Answer 1

Not tested, but your “event” loop, if you’re wanting it to run on the thread, would look something like this:

private bool running = true;
private AutoResetEvent waiter = new AutoResetEvent(false);

public void Run()
{
    FileSystemWatcher watcher = new FileSystemWatcher("C:\\");
    FileSystemEventArgs changes = null;

    watcher.Changed +=
        (object sender, FileSystemEventArgs e) => {
            changes = e;
            waiter.Set();
        };

    watcher.EnableRaisingEvents = true;

    while (running)
    {
        waiter.WaitOne();
        if (!running) break;

        Console.WriteLine("Path: {0}, Type: {1}",
                changes.FullPath, changes.ChangeType);
    }

    Console.WriteLine("Thread complete");
}

public void Stop()
{
    running = false;
    waiter.Set();
}

You would place this code in a class and run it on a separate thread (if you wish). If you want to have your main thread wait on the thread you create finishing (although why bother creating a thread in that case?) then you can use the Thread.Join method.