// This subroutine sends a response to the sender.
private void ReplyToSender(string strMessage, UserConnection sender)
{
sender.SendData(strMessage);
}
// This subroutine is used a background listener thread to allow reading incoming
// messages without lagging the user interface.
private void DoListen()
{
try {
// Listen for new connections.
listener = new TcpListener(System.Net.IPAddress.Any, _serverPort);
listener.Start();
do
{
// Create a new user connection using TcpClient returned by
// TcpListener.AcceptTcpClient()
UserConnection client = new UserConnection(listener.AcceptTcpClient());
// Create an event handler to allow the UserConnection to communicate
// with the window.
client.LineReceived += new LineReceiveEventHandler(OnLineReceived);
//AddHandler client.LineReceived, AddressOf OnLineReceived;
}while(true);
}
catch(Exception ex){
System.Console.WriteLine(ex.ToString());
}
}
// This is the event handler for the UserConnection when it receives a full line.
// Parse the cammand and parameters and take appropriate action.
private void OnLineReceived(UserConnection sender, string data)
{
string[] dataArray;
// Message parts are divided by "|" Break the string into an array accordingly.
// Basically what happens here is that it is possible to get a flood of data during
// the lock where we have combined commands and overflow
// to simplify this proble, all I do is split the response by char 13 and then look
// at the command, if the command is unknown, I consider it a junk message
// and dump it, otherwise I act on it
// dataArray = data.Split((char) 13);
dataArray = data.Split((char) 124);
// dataArray(0) is the command.
switch( dataArray[0])
{
case "CONNECT":
ConnectUser(dataArray[1], sender);
DataManager(dataArray[1], data);
break;
case "DISCONNECT":
DisconnectUser(sender.Name);
DataManager(sender.Name, data);
break;
default:
DataManager(sender.Name, data);
break;
}
}
// This subroutine checks to see if username already exists in the clients
// Hashtable. if it does, send a REFUSE message, otherwise confirm with a JOIN.
private void ConnectUser(string userName, UserConnection sender)
{
if (clients.Contains(userName))
{
ReplyToSender(EConnectionResponse.ConnectionRefused.ToString(), sender);
}
else
{
sender.Name=userName;
clients.Add(userName, sender);
System.Console.WriteLine("CONNECTED: "+sender.Name);
ReplyToSender(EConnectionResponse.ConnectionAccepted.ToString(), sender);
}
}