Visual Basic

Re: Using SMTP, the email is sent only when the Form is closed

25-Mar-09 16:30

Hi everyone,

I have a form with only one button, "Send", to test the code to send SMTP emails.

It fires the click event when I hit the "Send" button, but the email is never sent if I leave the form running. When I close the form, the email is sent.

This is not the needed behavior because the User may never close the Application or the Form to send emails (this is a Client/Server application, not Web).

Does anyone have an idea why is this happening or what should I change in the code?

Below is the code behind the "Send" button's click event:

Dim message As New MailMessage()
Dim client As New SmtpClient()

'Set the sender's address
message.From = New MailAddress("paulog@corpdev09.com")

message.To.Add(New MailAddress("recipient-test@corpdev09.com"))
message.CC.Add(New MailAddress("paulo-second@corpdev09.com"))

'Set the subject and message body text
message.Subject = "This is the email subject"
message.Body = "This is the body of the email"

'Set the SMTP server to be used to send the message
'client.Host = "DEV-EXCP09-CORPDEV.COM"

'Send the e-mail message
Try
client.Send(message)
Catch exMessage As Exception
MessageBox.show("Error: " + exMessage.Message)
End Try

Thanks,

Paulo

Henry Minute26-Mar-09 1:48

Re: Using SMTP, the email is sent only when the Form is closed

26-Mar-09 1:48

Have you tried using SendAsync(message) instead of Send(message)?

Henry Minute

Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”

paulogomes26-Mar-09 7:36

Re: Using SMTP, the email is sent only when the Form is closed

26-Mar-09 7:36

Hi Henry,

Thanks for your answer. Yes, I changed the code and tried SendAsync with the same result in VB. I also got the below code snipe in C#:
private static void SendAynchronousEmail(SmtpClient client)
{
MailMessage message = new MailMessage();
message.To.Add(RecipientEmail);
message.From = new MailAddress(SenderEmail);
message.Subject = "Asynchronous Email Test";
message.Body = "This is a test email, sent asynchronously.";
client.SendCompleted += new SendCompletedEventHandler
(mailDeliveryComplete);
client.SendAsync(message, "Test");

Console.WriteLine("Sending finished, press Enter.");
Console.ReadLine();
}
It sends the email only after you hit Enter. If you remove the Console.ReadLine()the email is never sent!
The code in the mailDeliveryComplete just write in the console "Message Sent".

I'm lost.
All code snipes I see in books and Internet are straight forward like above but none works, only after you close the application.

Any idea what is missing?

Thanks,

Paulo

Luc Pattyn26-Mar-09 9:02

Luc Pattyn

26-Mar-09 9:02

My guess is the Console is behaving in a logical way and you are fooling yourself. Whenever you execute Console.ReadLine() the console awaits your input and delays all its output. So "Message Sent" can not be shown as long as you don't hit ENTER.

To prove this, add the following right after Console.ReadLine():

Console.WriteLine("please hit ENTER once more");
Console.ReadLine();

Luc Pattyn [Forum Guidelines] [My Articles]

Re: Using SMTP, the email is sent only when the Form is closed

paulogomes26-Mar-09 9:14

Re: Using SMTP, the email is sent only when the Form is closed

26-Mar-09 9:14

Hi Luc,
Yes, you are right. But the point is not the command console.readline() but the fact that if I remove it the email is not sent.

In MSDN I found that if you use the synchronous Send method your code does not goes until the request is completed. This is why I'm using SendAsync that is asynchronous and it should not wait and send the email, not matter what the code does after.

I put the console.readline() only to be able to see the messages, I never tought that if I remove it the email is never sent.

Must be a reason for that...

Thanks for you reply. I'm still trying to find a way to send SMTP emails without having to finish the thread.

Thanks,

Paulo

Henry Minute26-Mar-09 9:12

Re: Using SMTP, the email is sent only when the Form is closed

26-Mar-09 9:12

See what happens if you follow Lucs' suggestion.
I'll watch the thread, in case you come back.

Luc Pattyn26-Mar-09 9:50

Luc Pattyn

26-Mar-09 9:50

Hi Paulo,

I have a C# program that, amongst a lot of other stuff, contains mail code, basically identical to yours (the synchronous version, that is):

MailMessage msg=new MailMessage();
... // set msg.properties
SmtpClient client = new SmtpClient(server);
client.Send(msg);

The only difference is my client is constructed with the server's name as a parameter.
My program successfully sends three mails without exiting at all.
My best guess is your observation somehow is wrong.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

modified on Thursday, March 26, 2009 4:23 PM

Re: Using SMTP, the email is sent only when the Form is closed

paulogomes26-Mar-09 10:49

Re: Using SMTP, the email is sent only when the Form is closed

26-Mar-09 10:49

Hi Luc/Henry,
I tried to build the SMTP client as Luc suggested but did not work either.

However, I found what the problem was: follow me.

when I started this project I did not know if I'll be using MAPI or SMTP, so I wrote 2 methods. Testing the MAPI time ago (with MAPI we use here Exchange Server), when the email is sent ExchangeServer pops a dialog box telling me that a program (my application) "is trying to send an email on your behalf" and give me an OK and CANCEL buttons. Once I hit OK, the email is sent.

That is the key: I'm testing the code using my own equipment, sending emails to me to see if it works or not. Did you see what happened?

SMTP does not have all Exchange Server features and does not issue a dialog asking for authorization, but it keeps waiting because I'm sending emails from my equipment to myself, but the user is not me, is my application, using my credencials!

As a proof of concept for this theory, I installed the application in another computer in the network and it worked fine, no more need to close the sending thread!

Nothing is wrong with those VB and C# codes, just the way I'm testing.

So, Luc/Henry, I really appreciate your effords and time spent to help me and it was a good felling having someone in the other side to discuss with my tech problems.

Thank you!

Paulo

Luc Pattyn26-Mar-09 10:59

Luc Pattyn

26-Mar-09 10:59

Hi Paulo,

glad you got it working.

However I'm not familiar with Exchange Server, and I do not quite follow your reasoning.

Are you saying:
1. Exchange Server does not want to accept your app sending something until the app exits?
2. Exchange Server does not deliver the newly received message as long as the app is running, because the app is impersonating you and "you" (the app) are not asking for incoming mail until the app exits and your regular mail client becomes active again?

Furthermore: would your app succeed in sending without exiting, if you did close your mail client beforehand?

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Re: Using SMTP, the email is sent only when the Form is closed

paulogomes26-Mar-09 11:38

Error trying to draw on form

26-Mar-09 11:38

Hi Luc,

About exchange server, it asks for authorization because the app (that is not me) is using my credencials to send email. This also happens when you get a virus kind Trojan and it tries to send emails from your equipment (it did happened before with me). The antivirus also catch this kind too.

I noticed that because the confirmation dialog box exchange server issued. But now I'm not using exchange server and MAPI, I'm using our SMTP server and it does not issue a dialog. If I issue 3 or 4 emails all go to the SMTP queue and all are sent only when the task is closed.

But if I use other equipment than mine, it works fine.

I tried to close the mail session bforehand, but it did not work either.

Anyways, it is something to keep in mind for our future development needs.

Thanks Luc.

Anytime.

Paulo

o m n i25-Mar-09 16:11

o m n i

25-Mar-09 16:11

Ok I'm trying to make a simple inkball type game.
But, I'm getting some wierd errors. Here is my code.

Public Class Form1
    Public ink() As Point
    Public g As Graphics = Me.CreateGraphics

    Private Sub Panel1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Panel1.MouseDown
        If e.Button = Windows.Forms.MouseButtons.Left Then
            Dim p = ink.Length
            ink(p).X = e.X
            ink(p).Y = e.Y
        End If
    End Sub

    Private Sub Panel1_Paint(ByVal sender As System.Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Panel1.Paint
        For Each p As Point In ink
            g.DrawRectangle(Pens.Black, New Rectangle(p.X, p.Y, 1, 1))
        Next
    End Sub
End Class

I've tried changing g to be Panel1.creategraphics, since the panel is what it would be drawing on but that causes even more problems. The errors I am getting are all 'Object Reference Not set to an instance of an object."

Have you tried the Krypton Toolkit? http://www.componentfactory.com/free-windows-forms-controls.php

Re: Error trying to draw on form

Bharat Jain25-Mar-09 19:07

Bharat Jain

25-Mar-09 19:07

I really don't understand what you are trying to do , but the error you are getting is because you have not initialized the array ink() , it is still Nothing and hence are getting the error , was not able to understand the logic you are trying to apply , looking at the code it don't think it is going draw anything Frown | :(

. The only thing i can suggest is initialized the array before using it.

-Regards
Bharat Jain
bharat.jain.nagpur@gmail.com

Re: Error trying to draw on form

Dave Kreskowiak26-Mar-09 4:31

Dave Kreskowiak

26-Mar-09 4:31

The graphics object you created is one for the form, not the panel. You get the graphics object for the panel from the Panel1 Paint event, like this:

Private Sub Panel1_Paint(ByVal sender as System.Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Panel1.Paint
    Dim g As Graphics = e.Graphics
 
    For Each p As Point In Ink
        g.Draw....
    Next
End Sub

But, of course, you'll have to modify the paint code to check to see if there are any points at all in the Ink array.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008

save array [modified]

moonshaddow25-Mar-09 15:44

moonshaddow

25-Mar-09 15:44

i am just wondering if anyone know(or have links) of a way to save a array inside the application code?

If at first you don't succeed
redefine success

J.Hardy

modified on Wednesday, March 25, 2009 9:52 PM

o m n i25-Mar-09 16:19

o m n i

25-Mar-09 16:19

Dim p(3) As Point 'create an array of 4 points (1-3 and 0)
        p(0) = New Point(640, 480) 'assign values to the points
        p(1) = New Point(800, 600)
        p(2) = New Point(1280, 748)
        p(3) = New Point(769, 999)
        Dim r As New String("") 'create a blank string
        For Each ipoint As Point In p 'loop through the points
            r &= "Point is located at: " & ipoint.ToString & vbNewLine 'write a string about the point
        Next
        MessageBox.Show(r) 'display the string with the info

Hope it helps! Smile | :)

Have you tried the Krypton Toolkit? http://www.componentfactory.com/free-windows-forms-controls.php

moonshaddow25-Mar-09 16:40

moonshaddow

25-Mar-09 16:40

sorry allow me to explain better, when i publish my application to a exe i need to store a array inside the exe(this will make the application grow in size), so next time when i open it the contents of the array will be there

If at first you don't succeed
Redefine success

J.Hardy

Ashfield25-Mar-09 22:47

Ashfield

25-Mar-09 22:47

You don't save data in your exe, you save it in an external file (for example app.config or as user settings) and load it in - unless you are talking about an hardcoded set of values, in which case the code to populate the array will be in the exe anyway.

Bob
Ashfield Consultants Ltd
Proud to be a 2009 Code Project MVP

I have a final working project in Visual basic 2008.

moonshaddow26-Mar-09 12:48

moonshaddow

26-Mar-09 12:48

dam, oh well, thanks anyway

If at first you don't succeed
Redefine success

J.Hardy

katie2325-Mar-09 12:34

katie23

25-Mar-09 12:34

How can i make the file executable by someone else with out the need of downloading a visual basic program onto their computer?

Re: I have a final working project in Visual basic 2008.

Henry Minute25-Mar-09 13:13

Re: I have a final working project in Visual basic 2008.

25-Mar-09 13:13

Search for click-once deployment.

tech60325-Mar-09 20:00

tech603

25-Mar-09 20:00

This link will show you how to switch to a from debug to release in Visual Studio, once you build the project you will notice that in the project folder there is a bin folder that should contain a debug folder and release folder. Inside these folders are the executable you need for distributing. You can zip up your files or use on click installers to package your project.

This link is for vs 2005:

http://msdn.microsoft.com/en-us/library/wx0123s5(VS.80).aspx[^]

if the above doesn't help try this link:

http://social.msdn.microsoft.com/Forums/en-US/winforms/thread/865ea184-70a5-4905-8dd7-089fd9714209/[^]

hope this helps

Matthew Vass
QA Analyst
mvass@hostmysite.com
HostMySite.com

Re: I have a final working project in Visual basic 2008.

katie2325-Mar-09 21:33

katie23

25-Mar-09 21:33

thanks for your help.

Easy Q:How to find the longest name(user input) in an array?

Haroon Ghazni25-Mar-09 11:31

Haroon Ghazni

25-Mar-09 11:31

Hey got a question about visual basic. Got a project for college to write a small code for a button to search an array called 'Members(0)'. The programme basically gets the user to input data via a input box (name, age only) and this button needs to find the LONGEST name in the array. And display it in the text box called 'txtResult.text'

Here's the code I have so far;

Private Sub btnLongName_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLongName.Click
Dim LongName As String
Dim LengthOfLongestName As Integer
LongName = Members(0).Name
LengthOfLongestName = Len(Members(0).Name)
End Sub
End Class

Re: Easy Q:How to find the longest name(user input) in an array?

Henry Minute25-Mar-09 11:55