Build Your Own ASP.NET 2.0 Web Site Using C# & VB, Second Edition

Figure 14.17. Viewing the email

Creating the Company Newsletter Page

Let’s now extend the Dorknozzle site structure by adding a Newsletters page.

This page will be accessible only to the site administrator, and will provide tools

with which a customized newsletter can be sent to a list of recipients.

Open the Dorknozzle project in Visual Web Developer, and add to it a new web

form named AdminNewsletter.aspx, making sure both the Select master page

and Create code in a separate file checkboxes are checked. When prompted, select

the Dorknozzle.master master page.

Complete the generated code like this:

File: AdminNewsletter.aspx

<%@ Page Language="VB" MasterPageFile="~/DorkNozzle.master"

AutoEventWireup="false" CodeFile="AdminNewsletter.aspx.vb"

Inherits="AdminNewsletter" Title="Dorknozzle Admin Newsletter"

%>

<asp:Content ID="Content1"

ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">

<h1>Create Newsletter</h1>

<asp:Label ID="resultLabel" runat="server" ForeColor="Red"/>

<br />To:<br />

<asp:TextBox ID="toTextBox" runat="server" />

<br />Subject:<br />

<asp:TextBox ID="subjectTextBox" runat="server" />

<br />Introduction:<br />

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Creating the Company Newsletter Page

<asp:TextBox ID="introTextBox" runat="server"

TextMode="MultiLine" Width="300" Height="100" />

<br />Employee Of The Month:<br />

<asp:TextBox ID="employeeTextBox" runat="server" />

<br />Featured Event:<br />

<asp:TextBox ID="eventTextBox" runat="server" />

<br />

<asp:Button ID="sendNewsletterButton" runat="server"

Text="Send Newsletter" />

</asp:Content>

Switch to Design View. The form should look like the one shown in Figure 14.18.

As you can see, the form contains seven TextBox controls, plus a Button and a

Label. The boxes will allow the administrator to specify who the email is to be

sent to and what the subject is, enter a simple introduction, identify the employee

of the month, and feature a company event and a store item. The Button control

is used to submit the form, while the Label control will display a confirmation

message once the email has been sent.

To ensure that only administrators can send email messages, add the code high-

lighted in bold below, which we discussed in detail in Chapter 13, to Web.config:

File: Web.config (excerpt)

<!-- Only administrators are allowed to access

AdminTools.aspx -->

<location path="AdminTools.aspx">

<system.web>

<authorization>

<allow roles="Administrators" />

<deny users="*" />

</authorization>

</system.web>

</location>

<!-- Only administrators are allowed to send emails -->

<location path="AdminNewsletter.aspx">

<system.web>

<authorization>

<allow roles="Administrators" />

<deny users="*" />

</authorization>

</system.web>

</location>

</configuration>

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Chapter 14: Working with Files and Email

Figure 14.18. The Create Newsletter form

One hurdle that we need to overcome is that we want to include an image to be

displayed as part of the HTML content of the message. We can use either of two

approaches to solve this problem:

❑

Host the image on our web server and reference it in an <img> tag in the

HTML code of the message (e.g. <img src="http://www.dorknozzle.com/Im-

ages/Newsletter.jpg" …>).

❑

Embed the image data in the email.

We’ll apply the first technique, as it has the benefit of simplicity, and keeps the

message as small as possible. If you want readers to see the image even when

they’re not connected to the Internet, you should look into the second option.

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Creating the Company Newsletter Page

Developer Mike Pope explained image embedding, and provided sample code,

in a post on his blog.

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All we need to do is handle the Send Newsletter button’s Click event. While in

Design View, double-click the button to generate the event handler signature. In

the code-behind file, we’ll need to import the System.Net.Mail namespace:

Visual Basic File: AdminNewsletter.aspx.vb (excerpt)

Imports System.Net.Mail

C# File: AdminNewsletter.aspx.cs (excerpt)

using System.Net.Mail;

Then, complete the code of sendNewsletterButton_Click to send your newslet-

ter:

Visual Basic File: AdminNewsletter.aspx.vb (excerpt)

Protected Sub sendNewsletterButton_Click( _

ByVal sender As Object, ByVal e As System.EventArgs) _

Handles sendNewsletterButton.Click

Dim smtpClient As SmtpClient = New SmtpClient()

Dim message As MailMessage = New MailMessage()

' Try to send the message

Try

' Prepare two email addresses

Dim fromAddress As New MailAddress( _

"[e-mail]", "Your Friends at Dorknozzle")

Dim toAddress As New MailAddress(toTextBox.Text)

' Prepare the mail message

message.From = fromAddress

message.To.Add(toAddress)

message.Subject = subjectTextBox.Text

message.IsBodyHtml = True

message.Body = _

"<html><head><title>" & _

HttpUtility.HtmlEncode(subjectTextBox.Text) & _

"</title></head><body>" & _

"<img src=""http://www.cristiandarie.ro/Dorknozzle" & _

"/Images/newsletter_header.gif"" />" & _

"<p>" & _

HttpUtility.HtmlEncode(introTextBox.Text) & "</p>" & _

"<p>Employee of the month: " & _

HttpUtility.HtmlEncode(employeeTextBox.Text) & "</p>" & _

3

http://www.mikepope.com/blog/DisplayBlog.aspx?permalink=1264

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Chapter 14: Working with Files and Email