Exception Handling

Fed · February 15th, 2010, 07:03 PM

Imar,

I'm stuck again...

I wanted to handle the exception generated if/when there is a problem with the mail server as depicted in your 3.5 book to the file share app but ran into a problem.

The file share uses a VB standalone program not an aspx code behind.

File share uses this method for diplaying a successful mail sent;

ASPX VB

Code:

 'send an email to the recipient...
            Utilities.SendEmail(txtRecipientEmail.Text, _
                txtSenderEmail.Text, Config.EmailSubject, emailBody)
            Server.Transfer("UploadComplete.aspx", True)

The above UploadComplete.aspx is a page that says 'message sent' and notice how he uses the Server.Transfer to display the page.

So in the interest of not rewriting the file share I figured I could use the same system and mad an UploadIncomplete.aspx that says 'message not sent', but when I created the Try, Catch in the standalone VB I discovered that Server.Transfer does not work.

VB

Code:

''' <summary>
    ''' SendEmail is used to send an email with the established settings and parameters
    ''' </summary>
    Public Shared Sub SendEmail(ByVal MsgTo As String, ByVal MsgFrom As String, ByVal MsgSubject As String, ByVal MsgText As String)
        Dim SmtpSettings As MailSettings
        SmtpSettings = GetSmtpSettings()
        Dim SmtpCl As New SmtpClient(SmtpSettings.MailServer, SmtpSettings.MailPort)
        SmtpCl.Credentials = GetCredentials(SmtpSettings)
        Dim MailMsg As New MailMessage(MsgFrom, MsgTo)
        MailMsg.Subject = MsgSubject
        MailMsg.Body = MsgText
        Try
            SmtpCl.Send(MailMsg)
        Catch ex As Exception
            Server.Transfer("UploadIncomplete.aspx", True)
        End Try

    End Sub

My question, is there a quick and dirty way for me to accomplish this?

Thanks,

Fed

Old Pedant · February 15th, 2010, 07:11 PM

Yeah, Server is an object that only exists in ASP.NET. "Server" means the web server, usually IIS.

For standalone apps, you just have to invoke a method in your catch handler.

But, really, you probably didn't need to create a completely separate class if all you wanted to do was display an "oops, it didn't work" message. Could have done something as simple as

Code:

     Catch ex As Exception
        MsgBox( "Unable to send email to " & MsgTo & ", reason: " & ex.toString() )

But you could make any call you wished there in place of MsgBox.

Fed · February 16th, 2010, 12:25 PM

Thanks, I thought it was something like that. Is there a corresponding object that does the same thing in VB?

Old Pedant · February 16th, 2010, 04:24 PM

Short answer: No.

In a normal executable program, you don't have the concept of "pages" that you do with an internet system.

You could, of course, simply wipe out all content on the user's screen and replace it with a message. Essentially, that's what loading a new page into a browser does: All prior window content simply goes away and is replaced by the new content. Surely you can do something more elegant in a standalone app.

Fed · February 16th, 2010, 05:49 PM

Thanks at least I know what direction to go in. Just started learning so a lot of stuff has yet to sink in... :)