C# 4 and .NET 4

Creating a Windows service Program ❘ 671
Creating Core functionality for the service
You can build any functionality in a Windows Service, such as scanning for files to do a backup or a virus
check or starting a WCF server. However, all service programs share some similarities. The program must
be able to start (and to return to the caller), stop, and suspend. This section looks at such an implementation
using a socket server.
With Windows 7, the Simple TCP/IP Services can be installed as part of the Windows components.
Part of the Simple TCP/IP Services is a “quote of the day,” or qotd, TCP/IP server. This simple
service listens to port 17 and answers every request with a random message from the file
\system32\drivers\etc\quotes. With the sample service, a similar server will be built.
The sample server returns a Unicode string, in contrast to the good-old qotd server that returns an
ASCII string.
First, create a Class Library called QuoteServer and implement the code for the server. The following
walks through the source code of your QuoteServer class in the file QuoteServer.cs:
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
namespace Wrox.ProCSharp.WinServices
{
public class QuoteServer
{
private TcpListener listener;
private int port;
private string filename;
private List quotes;
private Random random;
private Thread listenerThread;
code snippet QuoteServer/QuoteServer.cs
The constructor QuoteServer() is overloaded so that a filename and a port can be passed to the
call. The constructor where just the file name is passed uses the default port 7890 for the server.
The default constructor defines the default filename for the quotes as quotes.txt:
public QuoteServer()
: this ("quotes.txt")
{
}
public QuoteServer(string filename)
: this(filename, 7890)
{
}
public QuoteServer(string filename, int port)
{
this.filename = filename;
this.port = port;
}
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