A C# server that reads local files as input and output new total numbers based on input.

CSharpServer.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace CSharpServer
{
    class Program
    {
        private static bool Close = false;
        private static readonly double Total = 1e10;
        static void Main(string[] args)
        {
            Console.WriteLine("Start server.");
            // Infinite main loop
            FileSystemWatcher watcher = new FileSystemWatcher("C:\\Users\\zhangc2\\Desktop\\MyServer");
            watcher.Changed += Watcher_Changed;
            watcher.Created += Watcher_Created;
            watcher.EnableRaisingEvents = true;
            while (!Close)
                Thread.Sleep(1000);
        }

        private static void Watcher_Created(object sender, FileSystemEventArgs e)
        {
            Console.WriteLine("File created.");
            if (e.Name == "Exit.txt")
                Close = true;
        }

        private static void Watcher_Changed(object sender, FileSystemEventArgs e)
        {
            Console.WriteLine("File changed.");
            string inputName  = "Input.txt";
            if (e.Name == inputName)
            {
                double input = Double.Parse(File.ReadAllText(inputName));
                double result = Total - input;
                File.WriteAllText("Output.txt", result.ToString());
            }

            Console.WriteLine("File created.");
            if (e.Name == "Exit.txt")
                Close = true;
        }
    }
}