How do I get this event-based console app to not terminate immediately?

Question

Source

class Program
{
    static void Main(string[] args)
    {
        var fw = new FileSystemWatcher(@"M:\Videos\Unsorted");
        fw.Created+= fw_Created;
    }

    static void fw_Created(object sender, FileSystemEventArgs e)
    {
        Console.WriteLine("added file {0}", e.Name);
    }
}

Question

Should be pretty self explanatory. I'm trying to create a file watcher so I can sort my videos for me automatically...how do I get the program to not terminate, ever?

I want to keep it console-based for now so I can debug it, but eventually I want to remove the console and just have it run in the background (I guess as a service).

Answer 1

Perhaps something like this:

class Program
{
    static void Main(string[] args)
    {
        var fw = new FileSystemWatcher(@"M:\Videos\Unsorted");
        fw.Changed += fw_Changed;
        fw.EnableRaisingEvents = true;

        new System.Threading.AutoResetEvent(false).WaitOne();
    }

    static void fw_Changed(object sender, FileSystemEventArgs e)
    {
        Console.WriteLine("added file {0}", e.Name);
    }
}

Update

In the spirit of helping anyone else that may be looking for a similar solution, as @Mark stated in the comments, there is also a way to use the WaitForChanged method of the FileSystemWatcher class to solve this question:

class Program
{
    static void Main(string[] args)
    {
        var fw = new FileSystemWatcher(@".");
        while (true)
        {
            Console.WriteLine("added file {0}",
                fw.WaitForChanged(WatcherChangeTypes.All).Name);
        }
    }
}

Doing so allows the application to wait indefinitely (or until the while is broken) for a file to be changed.

Answer 2

class Program
{
    static void Main(string[] args)
    {
        var fw = new FileSystemWatcher(@"M:\Videos\Unsorted");
        fw.EnableRaisingEvents = true;
        fw.Created += fw_Created;

        Console.ReadLine();

    }

    static void fw_Created(object sender, FileSystemEventArgs e)
    {
        Console.WriteLine("added file {0}", e.Name);
    }

}

Just had to EnableRaisingEvents apparently.

---

Found another solution that is perhaps even nicer:

class Program
{
    static void Main(string[] args)
    {
        var fw = new FileSystemWatcher(@"M:\Videos\Unsorted");
        fw.Created += fw_Created;
        while(true) fw.WaitForChanged(WatcherChangeTypes.All);
    }

    static void fw_Created(object sender, FileSystemEventArgs e)
    {
        Console.WriteLine("added file {0}", e.Name);
    }
}

Answer 3

You can wait forever using this:

System.Threading.Thread.Sleep(-1);

Answer 4

I have had the exact same problem as you. What i did is if the program is launched with the command line --console it will prompt you to hit enter to close, if no parameters it will expect to be launched as a service.

class MyExampleApp : ServiceBase
{

    public static void Main(string[] args)
    {
        if (args.Length == 1 && args[0].Equals("--console"))
        {
            new MyExampleApp().ConsoleRun();
        }
        else
        {
            ServiceBase.Run(new MyExampleApp());
        }
    }
    private void ConsoleRun()
    {
        Console.WriteLine(string.Format("{0}::starting...", GetType().FullName));

        OnStart(null);

        Console.WriteLine(string.Format("{0}::ready (ENTER to exit)", GetType().FullName));
        Console.ReadLine();

        OnStop();

        Console.WriteLine(string.Format("{0}::stopped", GetType().FullName));
    }
    //snip
}

Answer 5

Console apps are never a good way to test events due to this scenario. Whatever method you use, it has to halt the current thread, either sleep or lock in some while(true) loop, which pevents your events from firing or makes it almost impossible to hit breakpoints inside events. Use a windows app if you can.