ln.types/io/WatchedFile.cs

using System;
using System.IO;
namespace ln.types.io
{
    public class WatchedFile : IDisposable, ContentSource
    {
        public string FileName { get; private set; }
        public event FileSystemEventHandler Changed;

        FileSystemWatcher fileSystemWatcher;

        public WatchedFile(String filename)
        {
            FileName = filename;
            fileSystemWatcher = new FileSystemWatcher(filename);
            fileSystemWatcher.Changed += FileSystemWatcher_Changed;
        }

        public byte[] Content
        {
            get
            {
                using (FileStream fs = new FileStream(FileName,FileMode.Open))
                {
                    return fs.ReadBytes((int)fs.Length);
                }
            }
            set
            {
                using (FileStream fs = new FileStream(FileName, FileMode.OpenOrCreate, FileAccess.Write))
                {
                    fs.Position = 0;
                    fs.WriteBytes(value);
                }
            }
        }

        void FileSystemWatcher_Changed(object sender, FileSystemEventArgs e)
        {
            Changed?.Invoke(sender, e);
        }

        public void Dispose()
        {
            fileSystemWatcher.Dispose();
        }
    }
}