newbie to creating web controls

[GJH]

I am trying to develop some .NET web controls in VB or C# and need some
help.
Does anyone know any websites with a good tutorial on how to start. The MSDN
site is not helping me at all.

An example I have is code that will email, I simply want to create a button
that has all the email code inside it, so I just have to place the button on
my page and add some properties and be done. It works fine when adding the
properties for the Property tab but cant get any properties working from
codebehind.

What am I doing wrong?

thanks in advance, heres my code.

<DefaultProperty("Text"), ToolboxData("<{0}:EmailButton
runat=server></{0}:EmailButton>")> Public Class EmailButton

Inherits System.Web.UI.WebControls.Button

Dim emlto, emlfrom, emlcc, emlbcc, smtpText, emlSubj, emlBod, emlRedirect As
String

<Bindable(True), Category("Appearance"), DefaultValue("")> Property
SMTPServer() As String

Get

Return smtpText

End Get

Set(ByVal Value As String)

smtpText = Value

End Set

End Property

<Bindable(True), Category("Appearance"), DefaultValue("")> Property
EmailTo() As String

Get

Return emlto

End Get

Set(ByVal Value As String)

emlto = Value

End Set

End Property

<Bindable(True), Category("Appearance"), DefaultValue("")> Property
EmailFrom() As String

Get

Return emlfrom

End Get

Set(ByVal Value As String)

emlfrom = Value

End Set

End Property

<Bindable(True), Category("Appearance"), DefaultValue("")> Property
EmailCC() As String

Get

Return emlcc

End Get

Set(ByVal Value As String)

emlcc = Value

End Set

End Property

<Bindable(True), Category("Appearance"), DefaultValue("")> Property
EmailBcc() As String

Get

Return emlbcc

End Get

Set(ByVal Value As String)

emlbcc = Value

End Set

End Property

<Bindable(True), Category("Appearance"), DefaultValue("")> Property
EmailSubject() As String

Get

Return emlSubj

End Get

Set(ByVal Value As String)

emlSubj = Value

End Set

End Property

<Bindable(True), Category("Appearance"), DefaultValue("")> Property
EmailBody() As String

Get

Return emlBod

End Get

Set(ByVal Value As String)

emlBod = Value

End Set

End Property

<Bindable(True), Category("Appearance"), DefaultValue("")> Property
EmailGoToPage() As String

Get

Return emlRedirect

End Get

Set(ByVal Value As String)

emlRedirect = Value

End Set

End Property

Public Sub Emailer()

Try

Dim gjhMail As System.Web.Mail.MailMessage = New System.Web.Mail.MailMessage

System.Web.Mail.SmtpMail.SmtpServer = smtpText

gjhMail.BodyFormat = System.Web.Mail.MailFormat.Html

gjhMail.From = emlfrom

gjhMail.Subject = emlSubj

gjhMail.To = EmailTo()

gjhMail.Cc = emlcc

gjhMail.Bcc = emlbcc

gjhMail.Body = emlBod & "<br />" & vbCrLf & "<br />" & vbCrLf

System.Web.Mail.SmtpMail.Send(gjhMail)

Catch ex As Exception

End Try

End Sub



Protected Overrides Sub Render(ByVal output As System.Web.UI.HtmlTextWriter)

MyBase.Render(output)

End Sub

Protected Overrides Sub OnClick(ByVal e As System.EventArgs)

Emailer()

End Sub

 

[Mike MacMillan]

GJH,
the class looks fine, what issues are you having using it from a
codebehind? ie, how are you using it?

Mike

 

[GJH]

I'd like to be able to do this:
Private Sub EmailButton1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles EmailButton1.Click
EmailButton1.EmailBody = TextBox1.text

Response.Redirect(http://www.msn.com)

End Sub

but the button never retrieves the TextBox1.Text value. It is always
Nothing.
The Response.Redirect does work though, if i comment out the 1st line.


thanks in advance,
G

 

[Mike MacMillan]

GJH,
2 things here:

but the button never retrieves the TextBox1.Text value

are you certain the TextBox1 control has a valid .Text property
upon postback? ie, is viewstate restoring the value of the textbox?

The Response.Redirect does work though, if i comment out the 1st

line.
does this mean if you leave the line where it set the EmailBody
property uncommented, it throw an error? i can't imagine why else it
wouldn't run the Response.Redirect unless an error was thrown. if so,
what is the error?

Mike MacMillan

 

[GJH]

Mike, thanks so much for your responses,

If I leave the EmailBody = TextBox1.text and have the Redirect, it does not
redirect but sends me a blank email. BUT I get different results depending
upon where I put my Emailer() function in the control.
Things only seem to work when I have the settings in the Property's Tab set,
nothing really on the code behind. Am I missing some kind of call in my
control to have it read the codebehind page???

I have tried it in:

this sends 1 blank email before page is loaded
Protected Overrides Sub Render(ByVal output As
System.Web.UI.HtmlTextWriter)
Emailer()
MyBase.Render(output)
End Sub

this sends 1 blank email and does not redirect
Protected Overrides Sub OnClick(ByVal e As System.EventArgs)
Emailer()
End Sub

this sends 1 blank email and redirects
Private Sub EmailButton_Click(ByVal sender As Object, ByVal e As
System.EventArgs) Handles MyBase.Click
Emailer()
End Sub

 

[Mike MacMillan]

GJH,
im not sure i have enough info to give you a complete solution. my
recommendation though would be to remote the try-catch around the logic
in the Emailer() method and see if/what exception is thrown. were you
able to validate whether or not TextBox1 holds a valid value when
you're trying to set the .EmailBody property?

Mike MacMillan

 

[GJH]

Hi Mike,
I have it in a try/catch and the only time the .EmailBody has a value is
when I set it in the Properties Tab in the Designer. It never has a value
when I try to set it in the click event in codebehind. None of my properties
return a value from the button click event codebehind. Even if I try to set
a value in the page_load event, it still returns a value of Nothing.

I created a new Property named EmailGoToPage() which is just a string to
redirect to after the button is clicked. I am calling it like this in my
Emailer() method:
Page.Response.Redirect(EmailGoToPage())

and setting on the click event on my webpage like this:
EmailButton1.EmailGoToPage = "http://www.cnn.com"

and here is the error message I get:
Value cannot be null. Parameter name: url

I am doing: Inherits System.Web.UI.WebControls.Button for my control
So it should be just a button with all its regular features right?

Thanks again for your help,
Greg