Duplex Web Services

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

using ChatClient.TwoWayWS;
using System.Collections;
using System.Net;

namespace ChatClient
{

    public partial class Form1 : Form
    {

        private TwoWayWS.Service1 _ws = new TwoWayWS.Service1();
		private bool _formClosing = false;
		private int _myLastEventID = 0;
		private int _myLastEventsListResetId = 0;

        public Form1()
        {
            InitializeComponent();
			_ws.Url = Properties.Settings.Default.ChatClient_TwoWayWS_Service1;
			//NetworkCredential cred = CredentialCache.DefaultCredentials as NetworkCredential;
			//_ws.Credentials = cred;
			_ws.UseDefaultCredentials = true;

			_ws.ListenCompleted += new ListenCompletedEventHandler(_ws_ListenCompleted);

			// Start to listen by calling the listen webmethod which will wait for events
			_ws.ListenAsync(0, 0);

		}

		/// <summary>
		/// When Listen ws request returns then an event was registered and needs to be processed.
		/// Process the event and call the Listen webmethod again to listen for further events
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void _ws_ListenCompleted(object sender, ListenCompletedEventArgs e) {

			bool getAllUsers = false;

			ChatClient.TwoWayWS.EventObject[] events = e.Result;
			
			System.Diagnostics.Trace.WriteLine("_ws_ListenCompleted - Made it in - _formClosing=" + _formClosing);
			System.Diagnostics.Trace.WriteLine("_ws_ListenCompleted - " + events.Length);

			if (_formClosing)
				return;

			foreach (EventObject eventObj in events) {

				System.Diagnostics.Trace.WriteLine("_ws_ListenCompleted - event Object type " + eventObj.ToString());

				_myLastEventID = eventObj.EventID;
				_myLastEventsListResetId = eventObj.EventsListResetID;

				switch (eventObj.ToString()) {
					case "ChatClient.TwoWayWS.LoginEvent":
						// If list of users on UI is empty and we got a loggin event then call another ws to 
						// get a list of all the logged in users. This condition would be true first we log in
						// and we want a list of the current users. Otherwise just add the new user(someone else logging in)
						// to the bottom of our list.
						if (lvLoggedInUsers.Items.Count == 0)
							getAllUsers = true;
						else {
							LoginEvent le = eventObj as LoginEvent;
							// Login user may exist in the list due to bulk load of all logged on users. And the cached event
							// of the login can be now processed as well.
							try {
								if (!lvLoggedInUsers.Items.ContainsKey(le.UserName))
									lvLoggedInUsers.Items.Add(le.UserName, le.UserName, 0);
							}
							catch { }
						}
						break;
					case "ChatClient.TwoWayWS.LoggedOutEvent":
						LoggedOutEvent lo = eventObj as LoggedOutEvent;
						lvLoggedInUsers.Items.RemoveByKey(lo.UserName);
						break;
					case "ChatClient.TwoWayWS.MessageEvent":
						MessageEvent msg = eventObj as MessageEvent;
						string fromPart = "From " + msg.From + ":";
						// Add the line - Note SelectedText acts as an append text function.
						rtChatRoom.SelectionBackColor = Color.LightGray;
						rtChatRoom.SelectionColor = Color.Crimson;
						rtChatRoom.SelectedText = fromPart; // Append the text
						rtChatRoom.SelectionBackColor = Color.White;
						rtChatRoom.SelectionColor = Color.Black;
						rtChatRoom.SelectedText = " " + msg.Message; // Append the text
						rtChatRoom.SelectedText = "\n";
						break;
					default:
						// Non-event processing - increment the non-event count
						int nonEventCnt = int.Parse(lblNonEventCnt.Text);
						nonEventCnt++;
						lblNonEventCnt.Text = nonEventCnt.ToString();
						break;
				}

				// Get a list of all the currently logged in users - see comments above.
				if (getAllUsers) {
					LoginEvent[] allLoginEvents = _ws.GetAllUsers();

					foreach (LoginEvent le in allLoginEvents) {
						try {
							lvLoggedInUsers.Items.Add(le.UserName, le.UserName, 0);
						}
						catch { }
					}

					getAllUsers = false;
				}
				
			}

			// Sleep the current UI thread to simulate network latency 
			Application.DoEvents();
			int milliSecdelay = string.IsNullOrEmpty(txtListenDelay.Text) ? 0 : int.Parse(txtListenDelay.Text);
			System.Threading.Thread.Sleep(milliSecdelay * 1000);
			txtListenDelay.Text = "0"; // reset to no delay.
			
			// re-establish a listen request.
			System.Diagnostics.Trace.WriteLine("_ws_ListenCompleted - Calling _ws.ListenAsync() for " + txtUsername.Text);
			_ws.ListenAsync(_myLastEventID, _myLastEventsListResetId);

		}


		private void ListenForEvents() {
		}


		private void btnLogin_Click(object sender, EventArgs e) {
			LoginEvent le = new LoginEvent();
			le.UserName = txtUsername.Text;
			_ws.Login(le);
			#region Affect UI
			btnLogout.Enabled = true;
			btnLogin.Enabled = false;
			btnSend.Enabled = true;
			txtUsername.Enabled = false;
			#endregion
		}

		private void btnLogout_Click(object sender, EventArgs e) {
			LoggedOutEvent lo = new LoggedOutEvent();
			lo.UserName = txtUsername.Text;
			_ws.LogOut(lo);
			#region Affect UI
			btnLogout.Enabled = false;
			btnLogin.Enabled = true;
			btnSend.Enabled = false;
			txtUsername.Enabled = true;
			lvLoggedInUsers.Clear();
			rtChatRoom.Clear();
			#endregion

		}


		private void btnSend_Click(object sender, EventArgs e) {
			MessageEvent msg = new MessageEvent();
			msg.From = txtUsername.Text;
			msg.Message = txtMsg.Text;
			_ws.SendChatMessage(msg);
			txtMsg.Clear();
		}

		private void Form1_FormClosing(object sender, FormClosingEventArgs e) {
			this._formClosing = true;
			// Release the waiting Listener on the server by sending an abstract event object.
			_ws.ReleaseListeners(new EventObject());
		}

 


      
    }
}