Few days back one of my colleague was looking for a simple chat script in ASP.Net, but he can’t found one. Almost all of the chat scripts were in ASP and he want to do it for an internal site. So I thought about implementing one. And here is the simple script using ASP.Net’s Page method feature. For this I am using Windows Authentication, because it is for a intranet site, where users will be coming from one domain only.
Code behind – Global.asax
private List<string> onlineUsers;
void Session_Start(object sender, EventArgs e)
{
if (this.onlineUsers == null)
{
this.onlineUsers = new List</string><string>();
}
if (!this.onlineUsers.Contains(HttpContext.Current.User.Identity.Name))
{
this.onlineUsers.Add(HttpContext.Current.User.Identity.Name);
}
HttpContext.Current.Session["Users"] = this.onlineUsers;
}
void Session_End(object sender, EventArgs e)
{
if (this.onlineUsers != null)
{
this.onlineUsers.Remove(HttpContext.Current.User.Identity.Name);
}
HttpContext.Current.Session["Users"] = this.onlineUsers;
}
Web.Config
<authentication mode="Windows"/>
<authorization>
<deny users="?"/>
</authorization>
Default.aspx.cs
private static List</string><string> chatCollection;
[WebMethod(true)]
public static List</string><string> Add(string comment)
{
string user = HttpContext.Current.User.Identity.Name;
if (chatCollection == null)
{
chatCollection = new List</string><string>();
}
comment = comment.Replace("< ", "[").Replace(">", "]");
comment = GetSmileys(comment);
chatCollection.Add(string.Format("<tr><td>{0} :<font color=\"blue\">{1}</font></td></tr>", user, comment));
return chatCollection;
}
private static string GetSmileys(string comment)
{
if (comment.Contains("[:-)]"))
{
comment = comment.Replace("[:-)]", "<img src=\"icons\\smile.gif\"/>");
}
else if (comment.Contains("[;-)]"))
{
comment = comment.Replace("[;-)]", "<img src=\"icons\\wink.gif\"/>");
}
else if (comment.Contains("[:-(]"))
{
comment = comment.Replace("[:-(]", "<img src=\"icons\\frown.gif\"/>");
}
else if (comment.Contains("[:-D]"))
{
comment = comment.Replace("[:-D]", "<img src=\"icons\\biggrin.gif\"/>");
}
else if (comment.Contains("[:-|]"))
{
comment = comment.Replace("[:-|]", "<img src=\"icons\\blankstare.gif\"/>");
}
else if (comment.Contains("[B-)]"))
{
comment = comment.Replace("[B-)]", "<img src=\"icons\\cool.gif\"/>");
}
else if (comment.Contains("[}-)]"))
{
comment = comment.Replace("[}-)]", "<img src=\"icons\\devilish.gif\"/>");
}
else if (comment.Contains("[:-P]"))
{
comment = comment.Replace("[:-P]", "<img src=\"icons\\p.gif\"/>");
}
return comment;
}
[WebMethod(true)]
public static List</string><string> GetChat()
{
if (chatCollection == null)
{
chatCollection = new List</string><string>();
}
return chatCollection;
}
[WebMethod(true)]
public static List</string><string> GetUsers()
{
if (HttpContext.Current.Session["Users"] == null)
{
HttpContext.Current.Session["Users"] = new List</string><string>();
}
return HttpContext.Current.Session["Users"] as List</string><string>;
}
And finally the HTML
Default.aspx
< !DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>:: TEAM CHAT ::</title>
<script type="text/javascript">
function sendChat() {
var chatText = $get("txtChatInput").value;
if (chatText != "") {
PageMethods.Add(chatText, sendChat_Callback);
}
else {
$get("txtChatInput").focus();
}
return false;
}
function sendChat_Callback(response) {
displayChatText(response);
$get("txtChatInput").value = "";
$get("txtChatInput").focus();
}
function GetChat() {
PageMethods.GetChat(GetChat_Callback);
}
function GetChat_Callback(response) {
displayChatText(response);
}
function displayChatText(response) {
var result;
result = "<table>";
for (var i = response.length - 1; i >= 0; i--) {
result = result + response[i];
}
result = result + "</table>";
$get("chatOutputDiv").innerHTML = result;
}
function getUsers() {
PageMethods.GetUsers(GetUsers_Callback);
}
function GetUsers_Callback(response) {
$get("lstUsers").options.length = 0;
for (var i = response.length - 1; i >= 0; i--) {
addUsers(response[i]);
}
}
function addUsers(text) {
var optn = document.createElement("OPTION");
optn.text = text;
optn.value = text;
$get("lstUsers").options.add(optn);
}
function LoadUI() {
getUsers();
GetChat();
$get("txtChatInput").focus();
}
function showAbout() {
var msg = "Copyright (c) 2009 Anuraj. All rights reserved.\nLicenced under GNU GPL v2.";
msg += "\n\nVersion 0.2 : Supports Smileys\n";
msg += "Smileys should be in square brackets, like below,\ncase-sensitive(Sorry I will fix it later)\n";
msg += "Supported :- [:-)], [;-)], [:-(], [:-D], [:-|], [B-)], [}-)],[:-P]\n";
msg += "\n\nHappy Chatting [:)]\n";
alert(msg);
}
setInterval("LoadUI();", 5000);
</script>
<style type="text/css">
body
{
font-family: Calibri;
font-size: 11pt;
}
input
{
font-family: Calibri;
font-size: 11pt;
color: Blue;
}
.txt
{
border: solid 1px #000;
font-family: Calibri;
font-size: 11pt;
color: Black;
}
option
{
font-family: Calibri;
font-size: 11pt;
color: Blue;
}
h1
{
color: Blue;
font-size: xx-large;
text-decoration: underline;
text-align: center;
}
</style>
</head>
<body onload="javascript:LoadUI();">
<form id="form1" runat="server" onsubmit="javascript:return sendChat();">
<div>
<asp :ScriptManager runat="server" ID="scriptMgr" EnablePageMethods="true" ScriptMode="Release"
EnableViewState="false" />
<table cellpadding="0" cellspacing="0" border="0">
<tr>
<td colspan="2" style="text-align: center">
<h1>
:: TEAM CHAT ::
</h1>
<span>A simple chat script using ASP.Net and C#</span>
<a href="javascript:void('About');" title="About TeamChat" onclick="javascript:return showAbout
();">?</a>
</td>
</tr>
<tr>
<td>
<input class="txt" type="text" maxlength="1500" style="width: 340px;" id="txtChatInput" />
</td>
<td valign="middle">
<input type="button" id="cmdSubmit" value="Send" onclick="javascript:return sendChat();" />
</td>
</tr>
<tr>
<td colspan="2">
</td>
</tr>
<tr>
<td colspan="2" valign="top">
<div id="chatOutput" style="height: 300px; width: 400px; border: solid 1px #000;
overflow: scroll;">
<div id="chatOutputDiv" style="height: 280px; width: 380px;">
</div>
</div>
</td>
</tr>
<tr>
<td colspan="2">
</td>
</tr>
<tr>
<td colspan="2" valign="top">
<label>
Online Users</label><br />
<select class="txt" size="4" id="lstUsers" style="width: 400px; border: thin solid #000000;
font-family: Calibri; font-size: 11pt; color: #FFFFFF;">
<option>No users available </option>
</select>
</td>
</tr>
<tr>
<td colspan="2" style="text-align: center; font-size: 11px;">
Copyright © 2009 <a href="mailto:anuraj.p@mymailserver.com">Anuraj</a>. All rights
reserved.<br />
Licenced under GNU GPL v2.
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
Here is the Image “Team Chat” running on my machine
Team chat - asp.net script screenshot
Code seems like pretty self explantory. As wordpress don’t support zip attachments, I will upload, and give the source later.
Happy Chating 
I took the Emoticons from deviantart.com
, and the best part is browser compatibility, client only requires compatible with IE. Yes it was a refresher course for me, I revisited GridView templates, Page.IsPostback checking etc. Today I got a requirement like I need to validate few radio buttons. I searched for an implementation, I found we can use required field validator for RadioButtonList, but in my case it was Radio buttons (Initially it was RadioButtonList, but due to some customization issues, I changed it to Radio Buttons). Then I implemented a custom validator, and in the client validation function I hardcoded the Radio Button ids, because for the client validation function we can’t pass the parameters to the function. Same problem again I faced in a GridView, where the problem I found was I won’t get the client id of the radio button in the Item template. 
After doing some research I found we can extend the custom validator control using Validation Framework. And here is the implementation. Using this we can add properties to the source / sender parameter in the client side validation function.
