Question

 Sub Main()
            Try
                Dim output, filename1, filename2, filename3, date1, date2 As String

                'today's final
                output += "Report Dates: " & date1 & " and " & date2
                filename1 = "filename1.doc"
                SaveToFile(output, filename1)


                'today's daily
                output = "Report Dates: " & date1 & " and " & date2
                filename2 = "filename2.doc"
                SaveToFile(output, filename2)

                'yesterday's final
                output = "Report Dates: " & date1 & " and " & date2
                filename3 = "filename3.doc"
                SaveToFile(output, filename3)

    'email files here
    SendEmail(to, body,date1);

                'detele temp files
                DeleteFile(filename1)
                DeleteFile(filename2)
                DeleteFile(filename3)
            Catch e As Exception
                cEmail.SendErrorEmail("[e-mail]", e.Message)
            End Try

    End Sub

Sub SaveToFile(ByVal text As String, ByVal fileName As String)
        Dim path As String = "c:\temp\" & fileName
        Try
            If File.Exists(path) = True Then
                File.Delete(path)
            End If

            ' Create a file to write to.
            Dim sw As StreamWriter = File.CreateText(path)
            sw.WriteLine(text)
            sw.Flush()
            sw.Close()

            ' Open the file to read from.
            Dim sr As StreamReader = File.OpenText(path)
            Do While sr.Peek() >= 0
                Console.WriteLine(sr.ReadLine())
            Loop
            sr.Close()
        Catch e As Exception
            message = "in SaveToFile  " & e.Message
            cEmail.SendErrorEmail("[e-mail]", message)
        End Try
    End Sub



Sub DeleteFile(ByVal fileName As String)
        Dim path As String = "c:\temp\" & fileName
        Try

            If File.Exists(path) = True Then
                File.Delete(path)
            End If

        Catch e As Exception
            message = "in DeleteFile  " & e.Message
            cEmail.SendErrorEmail("[e-mail]", message)
        End Try
    End Sub

i’m getting the following error:

in DeleteFile The process cannot access the file
‘c:\temp\filename2.doc’ because it is being used by another process.

am i supposed to release any processes before deleting the files? what am i missing?

EDIT: here is my “Send Email” function that sends out the files

 Public Sub SendEmail(ByVal msgTo As String, ByVal msgBody As String, ByVal date1 As String)


        Dim mail As New MailMessage()
        Dim objSMTP As New SmtpClient()
        Dim filename As String

        ''''''''''''''''''''''''''''''''''''''


        Try
            mail.To.Add(msgTo)
            mail.Bcc.Add("[e-mail]")
            mail.Priority = MailPriority.Normal
            mail.IsBodyHtml = True
            mail.Subject = "subject"
            mail.Body = msgBody


            filename = "filename1.doc"
            Dim DOERecords As New Net.Mail.Attachment("C:\temp\" & filename) 'create the attachment
            filename = "filename2.doc"
            Dim FOERecords As New Net.Mail.Attachment("C:\temp\" & filename) 'create the attachment
            filename = "filename3.doc"
            Dim FOERecords2 As New Net.Mail.Attachment("C:\temp\" & filename) 'create the attachment


            mail.Attachments.Add(DOERecords) 'add the attachment
            mail.Attachments.Add(FOERecords) 'add the attachment
            mail.Attachments.Add(FOERecords2) 'add the attachment

            objSMTP.Send(mail)

        Catch ex As Exception
            Throw ex
        End Try
    End Sub

Answer 1

You need to dispose all Attachment objects, or you will leave open file handles behind.
You can simply call Dispose on the MailMessage. This will trigger the dispose on any attachments.

objSMTP.Send(mail) 
mail.Dispose()

this could be avoided if you encapsulate the mail object with the Using statement

Using(mail as MailMessage = New MailMessage())
....
End Using