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SendMailErrorEventArgs.Handled Property

Indicates if the SMTP exception that is contained in the Exception property has been handled.

Namespace:  System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)

public bool Handled { get; set; }

Property Value

Type: System.Boolean
If true, the exception is consumed and handled by the SendMailErrorEventHandler delegate. If false, the exception is rethrown, including the original call stack and error message.
The default is false.

The Handled property indicates if the Exception has been handled. The exception is raised by the SMTP mail provider when an e-mail message cannot be sent by the ChangePassword control or the CreateUserWizard. The most common reason for the exception is a configuration error in the <smtp> Element (Network Settings) of the machine configuration file. Although an error like this is typically discovered during the development and debugging of an application, mail servers can fail unexpectedly in a production environment, and you must determine whether you want the entire application to fail in that situation. If not, handling the event allows your application to proceed.

If you do not create an event handler for the SendMailError event, or if you create an event handler but leave the Handled property set to false, your Web application will stop running if an error occurs when sending an e-mail message, and ASP.NET will display an error message. Handling the event allows your Web application to continue to run even though an exception has occurred. This is useful when it is not critical to send an e-mail message. For example, if the exception occurs when a user is working through a multi-step wizard, it can be advantageous to log the error, display an informative message to the user, and allow the user to complete the wizard.

The following code example demonstrates an ASP.NET page that uses a ChangePassword Web control, and includes an event handler for the SendMailError event named SendMailError. The code example assumes that the ASP.NET Web site has been configured to use ASP.NET membership and Forms authentication, and that a user has been created whose name and password are known to you. For more information, see How to: Implement Simple Forms Authentication.

If the password change succeeds, the code in the SendingMail event handler attempts to send an e-mail message to the user to confirm the change. SMTP must already be configured on the server in order for this code example to work. For information about how to configure an SMTP server, see How to: Install and Configure SMTP Virtual Servers in IIS 6.0. For the purposes of this example, it is not necessary to configure an SMTP server; the example is constructed to test for a failure to send an e-mail message.

If a mail server is not configured correctly or some other error occurs and the e-mail message cannot be sent, the SendMailError function is called. A message is displayed to the user. In addition, an event is logged to the Windows Application event log with the assumption that an event source named MySamplesSite already exists. See the code example below to create the specified event source. For more information about creating an event source, see Server Event Handling in ASP.NET Web Forms Pages. The Handled property of the SendMailErrorEventArgs object is set to true to indicate that the error has been handled.

<%@ Page Language="C#" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  void MySendingMail(object sender, MailMessageEventArgs e)
  {
    Message1.Text = "Sent mail to you to confirm the password change.";
  }

  void MySendMailError(object sender, SendMailErrorEventArgs e)
  {
    Message1.Text = "Could not send email to confirm password change.";

    // The MySamplesSite event source has already been created by an administrator.
    System.Diagnostics.EventLog myLog = new System.Diagnostics.EventLog();
    myLog.Log = "Application";
    myLog.Source = "MySamplesSite";
    myLog.WriteEntry(
        "Sending mail via SMTP failed with the following error: " + 
        e.Exception.Message.ToString(), 
        System.Diagnostics.EventLogEntryType.Error);

    e.Handled = true;
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
  <title>ChangePassword including a SendMailError Event</title>
</head>
<body>
  <form id="form1" runat="server">
  <div style="text-align:center">

    <h1>ChangePassword</h1>

    <asp:LoginView ID="LoginView1" Runat="server" 
      Visible="true">
      <LoggedInTemplate>
        <asp:LoginName ID="LoginName1" Runat="server" FormatString="You are logged in as {0}." />
        <br />
      </LoggedInTemplate>
      <AnonymousTemplate>
        You are not logged in
      </AnonymousTemplate>
    </asp:LoginView><br />

    <asp:ChangePassword ID="ChangePassword1" Runat="server"
      BorderStyle="Solid" 
      BorderWidth="1" 
      CancelDestinationPageUrl="~/Default.aspx" 
      DisplayUserName="true"
      OnSendingMail="MySendingMail" 
      OnSendMailError="MySendMailError" 
      ContinueDestinationPageUrl="~/Default.aspx" >
      <MailDefinition 
        BodyFileName="~\MailFiles\ChangePasswordMail.htm" 
        Subject="Activity information for you">
        <EmbeddedObjects>
          <asp:EmbeddedMailObject Name="LoginGif" Path="~\MailFiles\Login.gif" />
          <asp:EmbeddedMailObject Name="PrivacyNoticeTxt" Path="~\MailFiles\PrivacyNotice.txt" />
        </EmbeddedObjects>
      </MailDefinition>
    </asp:ChangePassword><br />

    <asp:Label ID="Message1" Runat="server" ForeColor="Red" /><br />

    <asp:HyperLink ID="HyperLink1" Runat="server" 
      NavigateUrl="~/Default.aspx">
      Home
    </asp:HyperLink>

  </div>
  </form>
</body>
</html>

Use the following code example if you need to programmatically add the event source named MySamplesSite to your Application log. This event source must exist in order for the first code example to work correctly. The following code example requires Administrator privileges.

#region Using directives

using System;
using System.Collections.Generic;
using System.Text;
using System.Diagnostics;

#endregion

namespace CreateEventSource
{
    class Program
    {
        static void Main(string[] args)
        {

            try
            {
                // Create the source, if it does not already exist. 
                if (!EventLog.SourceExists("MySamplesSite"))
                {
                    EventLog.CreateEventSource("MySamplesSite", "Application");
                    Console.WriteLine("Creating Event Source");
                }

                // Create an EventLog instance and assign its source.
                EventLog myLog = new EventLog();
                myLog.Source = "MySamplesSite";

                // Write an informational entry to the event log.    
                myLog.WriteEntry("Testing writing to event log.");

                Console.WriteLine("Message written to event log.");
            }
            catch (Exception e)
            {
                Console.WriteLine("Exception:");
                Console.WriteLine("{0}", e.ToString());
            }
        }
    }
}

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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