Below class and its methods will help you in sending email alerts to the end users.

public class clsEmail
    {
        StringBuilder Strbuilder = new StringBuilder();
        StringBuilder obj1 = new StringBuilder();
        static string strMailFrom = System.Configuration.ConfigurationManager.AppSettings["mailFrom"];
        static string strMailTo = System.Configuration.ConfigurationManager.AppSettings["mailTo"];
        static string strMailCC = System.Configuration.ConfigurationManager.AppSettings["MailCC"];
        static string strMailBcc = System.Configuration.ConfigurationManager.AppSettings["MailBcc"];
        static string strSmtpServer = System.Configuration.ConfigurationManager.AppSettings["MailServer"];
        static string strUserName = System.Configuration.ConfigurationManager.AppSettings["mailUserName"];

        /// <summary>
        /// procedure used to send the mail notification to the end user.
        /// </summary>
        /// <param name="message"></param>
        /// <param name="subject"></param>
        public static void SendNewCustomerEmail(string message, string subject)
        {
            string Style1 = "style=’font-family: Verdana;font-weight: normal;font-size: 11px;color: black’";
            StringBuilder Strbuilder = new StringBuilder();
            try
            {
                if (message != string.Empty)
                {
                    // Create the Objects
                    System.Net.Mail.MailMessage objMsg = new System.Net.Mail.MailMessage();
                    System.Net.Mail.SmtpClient SmtpMail = new SmtpClient(strSmtpServer,25);
                    SmtpMail.Credentials = new NetworkCredential("EMailAddress", "Password");         
                    MailAddress fromAddress = new MailAddress(strMailFrom, "Testing");
                    objMsg.To.Add(strMailTo);
                    objMsg.CC.Add(strMailCC);
                    objMsg.Bcc.Add(strMailBcc);
                    objMsg.From = fromAddress;
                    objMsg.Subject = subject;
                    Strbuilder.Append("<form><div " + Style1 + "> Hi,<Br><br> " + message + "</Div></form>");
                    Strbuilder.Append("<form><div " + Style1 + "> Regards,<Br> Dev Team </Div></form>");
                    objMsg.Body = Strbuilder.ToString();
                    objMsg.IsBodyHtml = true;
                    objMsg.Priority = MailPriority.High;
                    objMsg.BodyEncoding = System.Text.Encoding.UTF8;    
                    SmtpMail.Send(objMsg);
                }
                else
                {
                }
            }
            catch (SmtpException E)
            {
                AeSharedLibrary.clsMessage.Show("Error :" + E.Message.ToString() + " : " + E.InnerException.Message.ToString());
            }
            finally
            {

            }

        }

        /// <summary>
        /// procedure used to send the mail notification to the end user.
        /// </summary>
        /// <param name="message"></param>
        /// <param name="subject"></param>
        public static void SendNewCustomerEmail(string EmailId, string message, string subject)
        {
            string Style1 = "style=’font-family: Verdana;font-weight: normal;font-size: 11px;color: black’";
            StringBuilder Strbuilder = new StringBuilder();
            string strSmtpServer = System.Configuration.ConfigurationManager.AppSettings["MailServer"];
            try
            {
                if (message != string.Empty)
                {
                    // Create the Objects
                    System.Net.Mail.MailMessage objMsg = new System.Net.Mail.MailMessage();
                    System.Net.Mail.SmtpClient SmtpMail = new SmtpClient(strSmtpServer, 25);
                    SmtpMail.Credentials = new NetworkCredential("EmailId", "Password");
                    MailAddress fromAddress = new MailAddress(EmailId, "Testing");
                    objMsg.To.Add(EmailId);
                    //objMsg.CC.Add(strMailCC);
                    //objMsg.Bcc.Add(strMailBcc);
                    objMsg.From = fromAddress;
                    objMsg.Subject = subject;
                    Strbuilder.Append("<form><div " + Style1 + "> Hi,<Br><br> " + message + "</Div></form>");
                    Strbuilder.Append("<form><div " + Style1 + "> Thnx,<Br> Dev Team </Div></form>");
                    objMsg.Body = Strbuilder.ToString();
                    objMsg.IsBodyHtml = true;
                    objMsg.Priority = MailPriority.High;
                    objMsg.BodyEncoding = System.Text.Encoding.UTF8;
                    SmtpMail.Send(objMsg);
                }
                else
                {
                }
            }
            catch (SmtpException E)
            {
                AeSharedLibrary.clsMessage.Show("Error :" + E.Message.ToString() + " : " + E.InnerException.Message.ToString());
            }
            finally
            {

            }
        }

        /// <summary>
        /// procedure used to send the mail notification to the end user.
        /// </summary>
        /// <param name="message"></param>
        /// <param name="subject"></param>
        public static void SendNewCustomerEmail(string EmailId, string message, string subject, DataSet _dsLoginDetails)
        {
            string Style1 = "style=’font-family: Verdana;font-weight: normal;font-size: 11px;color: black’";
            StringBuilder Strbuilder = new StringBuilder();
            string strSmtpServer = System.Configuration.ConfigurationManager.AppSettings["MailServer"];
            try
            {
                if (message != string.Empty)
                {
                    // Create the Objects
                    System.Net.Mail.MailMessage objMsg = new System.Net.Mail.MailMessage();
                    System.Net.Mail.SmtpClient SmtpMail = new SmtpClient(strSmtpServer,25);
                    SmtpMail.Credentials = new NetworkCredential("EmailID", "Password");
                    MailAddress fromAddress = new MailAddress(EmailId, "Testing");
                    objMsg.To.Add(EmailId);
                    //objMsg.CC.Add(strMailCC);
                    //objMsg.Bcc.Add(strMailBcc);
                    objMsg.From = fromAddress;
                    objMsg.Subject = subject;
                    Strbuilder.Append("<form><div " + Style1 + "> Hi,<Br><br> " + message + "</Div></form>");
                    Strbuilder.Append("<form><div " + Style1 + "> Regards,<Br> Dev Team </Div></form>");
                    objMsg.Body = Strbuilder.ToString();
                    objMsg.IsBodyHtml = true;
                    objMsg.Priority = MailPriority.High;
                    objMsg.BodyEncoding = System.Text.Encoding.UTF8;
                    SmtpMail.Send(objMsg);
                }
                else
                {
                }
            }
            catch (SmtpException E)
            {
                AeSharedLibrary.clsMessage.Show("Error :" + E.Message.ToString() + " : " + E.InnerException.Message.ToString());
            }
            finally
            {

            }
        }

        /// <summary>
        /// procedure used to send the mail Notification to the end user.
        /// </summary>
        /// <param name="obj_h">Hashtable</param>
        /// <param name="subject">string</param>
        public static void SendNewCustomerEmail(Hashtable obj_h, string subject, string EmailId, string message)
        {
            StringBuilder Strbuilder = new StringBuilder(5000);
            StringBuilder obj1 = new StringBuilder();
            string Strvalue = "";

            string Style1 = "style=’font-family: Verdana;font-weight: normal;font-size: 11px;color:black’";

            string Style2 = "style=’text-align: left;font-family: Verdana;font-weight: normal;font-size: 11px;width: 150px;border: 1px #EFEFEF solid;border-collapse: collapse;border-spacing: 0px’";
            try
            {

                System.Net.Mail.MailMessage objMsg = new System.Net.Mail.MailMessage();
                System.Net.Mail.SmtpClient SmtpMail = new SmtpClient(strSmtpServer,25);
                SmtpMail.Credentials = new NetworkCredential("EmailID", "Password");
                MailAddress fromAddress = new MailAddress(EmailId, "Testing");
                objMsg.To.Add("EmailAddress");
                objMsg.From = fromAddress;
                objMsg.Subject = subject;
                IDictionaryEnumerator En = obj_h.GetEnumerator();
                Strbuilder.Append("<form><div " + Style1 + "> Hello,<Br><Br></Div></form>");
                Strbuilder.Append("<table border=1 width=60%" + Style2 + ">");
                while (En.MoveNext())
                {
                    if (En.Value.ToString().Trim() != "")
                    {
                        Strvalue = En.Value.ToString();
                    }
                    else
                    {
                        Strvalue = "-";
                    }
                    Strbuilder.Append("<tr><td " + Style2 + ">" + En.Key + "</td><td " + Style2 + ">" + Strvalue + "</td> </tr>");
                }
                Strbuilder.Append("</table>");
                Strbuilder.Append("<form><div " + Style1 + "> Regards,<Br> Dev Team </Div></form>");

                objMsg.Body = Strbuilder.ToString();
                obj_h.Clear();
                objMsg.IsBodyHtml = true;
                objMsg.Priority = MailPriority.High;
                objMsg.BodyEncoding = System.Text.Encoding.UTF8;               
                SmtpMail.Send(objMsg);

            }
            catch (SmtpException E)
            {
                AeSharedLibrary.clsMessage.Show("Error :" + E.Message.ToString() + " : " + E.InnerException.Message.ToString());
            }
            finally
            {

            }

        }

        /// <summary>
        /// procedure used to send the mail Notification to the end user.
        /// </summary>
        /// <param name="obj_h">Hashtable</param>
        /// <param name="subject">string</param>
        public static void SendNewCustomerEmail(DataTable dt)
        {
            StringBuilder Strbuilder = new StringBuilder(5000);
            StringBuilder obj1 = new StringBuilder();
            string Strvalue = "";
            string Style1 = "style=’font-family: Verdana;font-weight: normal;font-size: 11px;color:black’";          
            string Style2 = "style=’text-align: left;font-family: Verdana;font-weight: normal;font-size: 11px;width: 150px;border: 1px #EFEFEF solid;border-collapse: collapse;border-spacing: 0px’";
            try
            {

                System.Net.Mail.MailMessage objMsg = new System.Net.Mail.MailMessage();
                System.Net.Mail.SmtpClient SmtpMail = new SmtpClient(strSmtpServer,25);
                SmtpMail.Credentials = new NetworkCredential("EmailID", "Password");
                MailAddress fromAddress = new MailAddress(dt.Rows[0]["EmailFrom"].ToString(), "Testing");

                objMsg.To.Add(dt.Rows[0]["EmailAddTo"].ToString());
                objMsg.CC.Add(dt.Rows[0]["EmailAddCC"].ToString());
                objMsg.Bcc.Add(dt.Rows[0]["EmailAddBCC"].ToString());
                objMsg.From = fromAddress;
                Hashtable obj_h = new Hashtable();
                IDictionaryEnumerator En = obj_h.GetEnumerator();
                objMsg.Subject = dt.Rows[0]["EmailSubject"].ToString();              
                Strbuilder.Append("<form><div " + Style1 + "> Hello,<Br><Br></Div></form>");
                Strbuilder.Append("<table border=1 width=60%" + Style2 + ">");
                while (En.MoveNext())
                {
                    if (En.Value.ToString().Trim() != "")
                    {
                        Strvalue = En.Value.ToString();
                    }
                    else
                    {
                        Strvalue = "-";
                    }
                    Strbuilder.Append("<tr><td " + Style2 + ">" + En.Key + "</td><td " + Style2 + ">" + Strvalue + "</td> </tr>");
                }
                Strbuilder.Append("</table>");
                Strbuilder.Append("<form><div " + Style1 + "> Regards,<Br> Billing Team </Div></form>");

                objMsg.Body = dt.Rows[0]["EmailBody"].ToString();
                Attachment attach = new Attachment(dt.Rows[0]["EmailAttachments"].ToString());
                objMsg.Attachments.Add(attach);
                objMsg.IsBodyHtml = true;
                objMsg.Priority = MailPriority.High;
                objMsg.BodyEncoding = System.Text.Encoding.UTF8;
               
               
               
                SmtpMail.Send(objMsg);

            }
            catch (SmtpException E)
            {
                AeSharedLibrary.clsMessage.Show("Error :" + E.Message.ToString() + " : " + E.InnerException.Message.ToString());
            }
            finally
            {

            }

        }
    }

Below class will help us in exporting the gridView data to the excel file.

  public class clsExportToExcel
    {

        public static void ExportDataSetToExcel(DataTable dTable, string filename)
        {
            HttpResponse response = HttpContext.Current.Response;
            response.Clear();
            response.Charset = "";
            response.ContentType = "application/vnd.ms-excel";
            response.AddHeader("Content-Disposition", "attachment;filename=\"" + filename + "\"");
            response.Cache.SetCacheability(HttpCacheability.NoCache);
            using (StringWriter sw = new StringWriter())
            {
                using (HtmlTextWriter htw = new HtmlTextWriter(sw))
                {
                    DataGrid dg = new DataGrid();
                    dg.DataSource = dTable;
                    dg.DataBind();
                    dg.RenderControl(htw);
                    response.Write(sw.ToString());
                    response.End();
                }
            }
        }
    }

Error logging in asp.net application using text file.Following class can help us in doing the same.

public class clsErrLogging
    {
        #region Function
        /// <summary>
        /// This function is used to open the file and write the error messages in that same file.
        /// </summary>
        /// <param name="msg"></param>
        public void LoggingErrors(string strMsg)
        {
            try
            {            
                string strPath = System.Configuration.ConfigurationManager.AppSettings["LogFilePath"];
                StreamWriter StrWriter = new StreamWriter(strPath, true);
                StrWriter.AutoFlush = true;
                StrWriter.WriteLine("———————" + DateTime.Now + "————————");
                StrWriter.WriteLine(DateTime.Now + " :: " + strMsg);
                StrWriter.WriteLine("———————" + DateTime.Now + "————————");
                StrWriter.Close();
              
              
            }
            catch (Exception ex)
            {
                string strErr = ex.Message;
            }          
        }
        #endregion Function
    }

Below Class can be used to display messages to the end user.(In Web applications).

public class clsMessage
    {
        protected static Hashtable handlerPages = new Hashtable();
        private clsMessage()
        {
        }

        public static void Show(string Message)
        {
            if (!(handlerPages.Contains(HttpContext.Current.Handler)))
            {
                Page currentPage = (Page)HttpContext.Current.Handler;
                if (!((currentPage == null)))
                {
                    Queue messageQueue = new Queue();
                    messageQueue.Enqueue(Message);
                    handlerPages.Add(HttpContext.Current.Handler, messageQueue);
                    currentPage.Unload += new EventHandler(CurrentPageUnload);
                }
            }
            else
            {
                Queue queue = ((Queue)(handlerPages[HttpContext.Current.Handler]));
                queue.Enqueue(Message);
            }
        }

        private static void CurrentPageUnload(object sender, EventArgs e)
        {

            Queue queue = ((Queue)(handlerPages[HttpContext.Current.Handler]));
            if (queue != null)
            {
                StringBuilder builder = new StringBuilder();
                int iMsgCount = queue.Count;
                builder.Append("<script language=’javascript’>");
                string sMsg;
                while ((iMsgCount > 0))
                {

                    iMsgCount = iMsgCount – 1;
                    sMsg = System.Convert.ToString(queue.Dequeue());
                    sMsg = sMsg.Replace("\"", "’");
                    builder.Append("alert( \"" + sMsg + "\" );");
                }
                builder.Append("</script>");
                handlerPages.Remove(HttpContext.Current.Handler);
                HttpContext.Current.Response.Write(builder.ToString());
            }
        }
    }

Pawan Kumar
Pawankkmr@hotmail.com

Following is the code to implement the breadcrumbs in asp.net

/* Add Web.sitemap.  To add this file, right click on Project Folder, select option "Add New Item".
Select Site Map and add file.  Your file should contain nodes like below :

<siteMap xmlns="http://schemas.microsoft.com/AspNet/SiteMap-File-1.0&quot; >
<siteMapNode url="~/default.aspx" title="Home"  description="Home">
<siteMapNode url="~/OrderDetails/OrderList.aspx" title="OrderList" description="" />
<siteMapNode url="" title="Search" description="" >
<siteMapNode url="~/GallerySearch/NewGallarySearch.aspx" title="Gallary Search"  description=""/>
<siteMapNode url="~/Search/Search.aspx" title="Advance Search"  description=""/>
</siteMapNode>
<siteMapNode url="" title="Administration"  description="">
<siteMapNode url="~/Partner/PartnerList.aspx" title="Partner List"  description="" >
<siteMapNode url="~/Partner/PartnerSummary.aspx" title="Partner Summary"  description="">
<siteMapNode url="~/Partner/EditPartner.aspx" title="Partner Edit"  description="" />
<siteMapNode url="~/Partner/PartnerProduct.aspx" title="Partner Product" description="" />
</siteMapNode>
</siteMapNode>
</siteMapNode>
<siteMapNode url="~/User/ViewaccountInfo.aspx" title="My Profile" description="" />
<siteMapNode url="" title="Help"  description="" />
</siteMapNode>
</siteMap>

/* To implement Breadcrumb upto first level of Querystring, add following code in your Global.aspx */

<%@ Application Language="C#" %>
<%@ Import Namespace="System.Diagnostics" %>

<script runat="server">
void Application_Start(object sender, EventArgs e)
{
// Code that runs on application startup
SiteMap.SiteMapResolve += new SiteMapResolveEventHandler(AppendQueryString);
}

void Application_End(object sender, EventArgs e)
{
//  Code that runs on application shutdown
}

void Application_Error(object sender, EventArgs e)
{
//Exception objErr = Server.GetLastError().GetBaseException();
//string err = "Error in: " + Request.Url.ToString() +
//                  ". Error Message:" + objErr.Message.ToString();
//if (Session["SessionInformation"] == null)
//{
//    Server.Transfer("../Logout.aspx");
//}
}

void Session_Start(object sender, EventArgs e)
{
// Code that runs when a new session is started
//HttpContext context = HttpContext.Current;
//HttpCookieCollection cookies = context.Request.Cookies;
}

void Session_End(object sender, EventArgs e)
{
// Code that runs when a session ends.
// Note: The Session_End event is raised only when the sessionstate mode
// is set to InProc in the Web.config file. If session mode is set to StateServer
// or SQLServer, the event is not raised.
Application_Error(sender, e);
}

//Function to add breadcrumb with Querystring.
SiteMapNode AppendQueryString(object o, SiteMapResolveEventArgs e)
{
if (SiteMap.CurrentNode != null)
{
SiteMapNode temp;
temp = SiteMap.CurrentNode.Clone(true);
Uri u = new Uri(e.Context.Request.Url.ToString());
temp.Url += u.Query;
if (temp.ParentNode != null)
{
temp.ParentNode.Url += u.Query;
}
return temp;
}
else
{
return null;
}
}

</script>

/* Add following tag in Master Page, where you want to implement site map.

<asp:SiteMapPath ID="SiteMapPath1" runat="server" Font-Names="Verdana" ParentLevelsDisplayed="8"
Font-Size="0.8em" PathSeparator=" ->">
<PathSeparatorStyle Font-Bold="True" ForeColor="#507CD1" />
<CurrentNodeStyle ForeColor="#333333" />
<NodeStyle Font-Bold="True" ForeColor="#284E98" />
<RootNodeStyle Font-Bold="True" ForeColor="#507CD1" />
</asp:SiteMapPath>

Gauri Deshpande / Pawan Kumar

Pawankkmr@hotmail.com