Filesystemwatcher C# high CPU usage

Question

I have created a very simple from example (console) of the filsystemwatcher to listen for changes on a single directory. I have then taken the exact code and used it in a very simple windows form that has just one list box for the console output, but I have spawned it as a thread - the console version uses 0% cpu whereas the same single thread uses 25% ANY Insights as to why ???

THREADED VERSION

 Thread pdfWatcher = new Thread(t => startFileWatcher(pdfStoragePath))
        { IsBackground = false };
        pdfWatcher.Start();
    }

private void startFileWatcher(string pdfOutputPath)
    {
        statusOutput.Items.Add("Starting Thread : File Watcher...");
        using (FileSystemWatcher watcher = new FileSystemWatcher())
        {
            watcher.Path = pdfOutputPath;
            messageStatusWindow("Watching Path : [" + pdfOutputPath + "] For new PDF's");


            // Watch for changes in LastAccess and LastWrite times, and
            // the renaming of files or directories.
            watcher.NotifyFilter = NotifyFilters.LastWrite;


            // Only watch text files.
            watcher.Filter = "*.pdf";

            // Add event handlers.
            //watcher.Changed += OnChanged;
            watcher.Created += OnCreated;
            //watcher.Deleted += OnChanged;
            //watcher.Renamed += OnRenamed;

            // Begin watching.
            watcher.EnableRaisingEvents = true;

            // Wait for the user to quit the program.
            Console.WriteLine("Press 'q' to quit the sample.");
            messageStatusWindow("Thread Started : File Watcher");
            while (Console.Read() != 'q') ;
        }
    }

CONSOLE VERSION

 class Program
{
    static void Main(string[] args)
    {
        if (args.Length != 2)
        {
            // Display the proper way to call the program.
            Console.WriteLine("Usage: FileWatcher.exe (directory)");
            return;
        }



        using (FileSystemWatcher watcher = new FileSystemWatcher())
        {
            watcher.Path = args[1];
            Console.WriteLine(args[0]);

            // Watch for changes in LastAccess and LastWrite times, and
            // the renaming of files or directories.
            watcher.NotifyFilter = NotifyFilters.LastAccess
                                 | NotifyFilters.LastWrite
                                 | NotifyFilters.FileName
                                 | NotifyFilters.DirectoryName
                                 | NotifyFilters.Size;

            // Only watch text files.
            watcher.Filter = "*.pdf";

            // Add event handlers.
            watcher.Changed += OnChanged;
            watcher.Created += OnCreated;
            watcher.Deleted += OnChanged;
            watcher.Renamed += OnRenamed;



            // Begin watching.
            watcher.EnableRaisingEvents = true;

            // Wait for the user to quit the program.
            Console.WriteLine("Press 'q' to quit the sample.");
            while (Console.Read() != 'q') ;
        }

in a

Answer 1

The line while (Console.Read() != 'q') ; is consuming all of your cpu. You must eigther use a message pump (no console application) or some kind of wait mechanism like while(Console.Read()!='g') System.Threading.Thread.Sleep(100);