Build Your Own ASP.NET 3.5 Website Using C# & VB (107 page)

Text="Send Newsletter" />

Switch to
Design
view. The form should look like the one shown in
Figure 14.15.

As you can see, the form contains five 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. 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 XML code

below, which we’
ve already discussed in detail in Chapter 13
, to
Web.config
:
Dorknozzle\VB\02_web.config
(excerpt)

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Build Your Own ASP.NET 3.5 Web Site Using C# & VB

Figure 14.15. 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 tag in the HTML

code of the message (for example,

src="http://www.dorknozzle.com/Images/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. Developer

Mike Pope explains image embedding, and provides sample code, in
a post on his

blog, titled “System.Net.Mail and embedded images.”2

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

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627

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 first need to import the System.Net.Mail namespace:

Visual Basic

Dorknozzle\VB\03_AdminNewsletter.aspx.vb
(excerpt)

Imports System.Net.Mail

C#

Dorknozzle\CS\03_AdminNewsletter.aspx.cs
(excerpt)

using System.Net.Mail;

Then, complete the code of sendNewsletterButton_Click to send your newsletter:

Visual Basic

Dorknozzle\VB\03_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

Dim fromAddress As New MailAddress( _

"[email protected]", "Your Friends at Dorknozzle")

Dim toAddress As New MailAddress(toTextBox.Text)

message.From = fromAddress

message.To.Add(toAddress)

message.Subject = subjectTextBox.Text

message.IsBodyHtml = True

message.Body = _

"" & _

"

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

"

" & _

HttpUtility.HtmlEncode(introTextBox.Text) & "

"

Employee of the month: " & _

HttpUtility.HtmlEncode(employeeTextBox.Text) & "

"

This months featured event: " & _

HttpUtility.HtmlEncode(eventTextBox.Text) & "

""

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Build Your Own ASP.NET 3.5 Web Site Using C# & VB

smtpClient.Host = "
localhost
"

smtpClient.Credentials = _

New System.Net.NetworkCredential("
username
", "
password
")
smtpClient.Send(message)

resultLabel.Text = "Email sent!
"

Catch ex As Exception

resultLabel.Text = "Couldn't send the message!"

End Try

End Sub

C#

Dorknozzle\CS\03_AdminNewsletter.aspx.cs
(excerpt)

protected void sendNewsletterButton_Click(

object sender, EventArgs e)

{

SmtpClient smtpClient = new SmtpClient();

MailMessage message = new MailMessage();

try

{

MailAddress fromAddress = new MailAddress(

"[email protected]", "Your Friends at Dorknozzle"

);

MailAddress toAddress = new MailAddress(toTextBox.Text);

message.From = fromAddress;

message.To.Add(toAddress);

message.Subject = subjectTextBox.Text;

message.IsBodyHtml = true;

message.Body =

"" +

"

"/Images/newsletter_header.gif\" />" +

"

" +

HttpUtility.HtmlEncode(introTextBox.Text) + "

"

Employee of the month: " +

HttpUtility.HtmlEncode(employeeTextBox.Text) + "

"

This months featured event: " +

HttpUtility.HtmlEncode(eventTextBox.Text) + "

"";

smtpClient.Host = "
localhost
";

smtpClient.Credentials =

new System.Net.NetworkCredential("
username
", "
password
");
smtpClient.Send(message);

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629

resultLabel.Text = "Email sent!
";

}

catch (Exception ex)

{

resultLabel.Text = "Couldn\'t send the message!";

}

}

That’s a pretty large chunk of code, so let’s break it down. Initially, we create a new

instance of the MailMessage class, called message:

Visual Basic

Dorknozzle\VB\03_AdminNewsletter.aspx.vb
(excerpt)

Dim message As MailMessage = New MailMessage()

C#

Dorknozzle\CS\03_AdminNewsletter.aspx.cs
(excerpt)

MailMessage message = new MailMessage();

Next, we begin to define the email message by setting some of the properties that

the MailMessage class exposes:

Visual Basic

Dorknozzle\VB\03_AdminNewsletter.aspx.vb
(excerpt)

Dim fromAddress As New MailAddress( _

"[email protected]", "Your Friends at Dorknozzle")

Dim toAddress As New MailAddress(toTextBox.Text)

message.From = fromAddress

message.To.Add(toAddress)

message.Subject = subjectTextBox.Text

message.IsBodyHtml = True

C#

Dorknozzle\CS\03_AdminNewsletter.aspx.cs
(excerpt)

MailAddress fromAddress = new MailAddress(

"[email protected]", "Your Friends at Dorknozzle"

);

MailAddress toAddress = new MailAddress(toTextBox.Text);

message.From = fromAddress;

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Build Your Own ASP.NET 3.5 Web Site Using C# & VB

message.To.Add(toAddress);

message.Subject = subjectTextBox.Text;

message.IsBodyHtml = true;

You’ll notice we’ve set the IsBodyHtml property to True because we’re creating an

HTML email message. By default, this property is set to False.

Next, we need to create the body of the message, which, essentially, will be an

HTML document:

Visual Basic

Dorknozzle\VB\03_AdminNewsletter.aspx.vb
(excerpt)

message.Body = _

"" & _

"