Simple chat application for ASP.NET

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Introduction

And why not, how to create an easy chat room for your web site? Well, the best way is to use a nice database to store messages; however, for demo purposes, I'll use a static array. I know, you won't be able to use it in your web farm. Take this article as the concept, not as a solution. This simple web chat program is intended to work in any browser supporting <iFrame>.

Also, you can select multiple chat rooms. Why not extend from there and more from channel to channel.

Background

Some months ago, I was looking for a complete on-line customer service ASP.NET control to make my life easier, did not find anything interesting, so I built my own.

Using the code

Replace this class if you are using a database to save the messages:

public class Chat
{
        static protected ArrayList pArray = new ArrayList();
        

        static public void AddMessage(string sDealer, 
                              string sUser, string sMsg)
        {
            string sAddText = sDealer + "~" + sUser + "~" + sMsg;
            pArray.Add(sAddText);

            if ( pArray.Count > 200 )
            {
                pArray.RemoveRange(0,10);
            }
        }

        static public string GetAllMessages(string sDealer)
        {
            string sResponse = "";

            for (int i=0; i< pArray.Count; i++)
            {
                sResponse = sResponse + 
                    FormatChat(pArray[i].ToString(), sDealer);
            }

            return(sResponse);
        }

        static private string FormatChat(string sLine, string sDealer)
        {
            int iFirst = sLine.IndexOf("~");
            int iLast = sLine.LastIndexOf("~");

            string sDeal = sLine.Substring(0, iFirst);
            if ( sDeal != sDealer)
                return("");

            string sUser = sLine.Substring(iFirst+1, iLast-(iFirst+1));
            
            string sMsg = sLine.Substring(iLast+1);

            string sRet = "" + sUser + ": " + sMsg + "";

            return(sRet);
        }
    }

The above code reads and writes from the static array like in a database. The code only allows having 200 messages in the array, after that it deletes the top 10 at the time.

The Chat page is pretty simple; this is the code behind aspx.cs:

public class ChatWin : System.Web.UI.Page
    {
        protected System.Web.UI.WebControls.TextBox TB_ToSend;
        protected System.Web.UI.WebControls.Button BT_Send;
    
        private void Page_Load(object sender, System.EventArgs e)
        {
            if ( Page.IsPostBack == false )
            {
                if ( Request.Params["Channel"] != null )
                    Session["ChatChannel"] = 
                       Request.Params["Channel"].ToString();
                else
                    Session["ChatChannel"] = "1";
                
            }
        }

        #region Web Form Designer generated code
        override protected void OnInit(EventArgs e)
        {
            //

            // CODEGEN: This call is required by the ASP.NET Web Form Designer.

            //

            InitializeComponent();
            base.OnInit(e);
        }
        
        /// <SUMMARY>

        /// Required method for Designer support - do not modify

        /// the contents of this method with the code editor.

        /// </SUMMARY>

        private void InitializeComponent()
        {    
            this.BT_Send.Click += 
               new System.EventHandler(this.BT_Send_Click);
            this.Load += new System.EventHandler(this.Page_Load);

        }
        #endregion

        public string GetChatPage()
        {
            return("TheChatScreenWin.aspx");
        }

        private void BT_Send_Click(object sender, System.EventArgs e)
        {
            string sChannel = "";
            string sUser = "";

            if ( Request.Params["Channel"] != null )
                sChannel = Request.Params["Channel"].ToString();
            else
                sChannel = "1";

            if ( Request.Params["User"] != null )
                sUser = Request.Params["User"].ToString();
            else
            {
                Random pRan = new Random();
                int iNum = pRan.Next(9);
                sUser = "Annonymouse" + iNum;
            }

            
            if ( TB_ToSend.Text.Length > 0)
            {
                PageModule.Chat.AddMessage(sChannel,
                    sUser,
                    TB_ToSend.Text);
                
                TB_ToSend.Text = "";        
            }
        }
    }

When the SEND button is clicked, it calls the function AddMessage that adds a row into the end of the static array.

The page inside the <iframe> tag refreshes every 4 seconds without refreshing your actual page.

Points of Interest

The magic? None, a simple request of the second page into the <iFrame>. So, Internet Explorer takes care of everything for us to read the static array.