bouton imprimer DGV complet - Visual Basic Discussion Boards

The .NET CLR abstracts keyboard devices away so that by .NET standard means you have no way of telling from which keyboard device a keypress event originated from. There's a Windows "Raw Input API" but it's not part of .NET so you would have to use P/Invoke ("DllImport") or a C++/CLI bridge if there wasn't this nice CP article (which uses P/Invoke):
Using Raw Input from C# to handle multiple keyboards[^]
A small drawback for you might be that it's written in C# but as you probably know, this doesn't stop you at all from using it in VB. I used it for exactly that purpose you're asking for.

I didn't know about that Microsoft Library you've linked. I took a look at it and at first glance, I don't think it's suitable.

If the brain were so simple we could understand it, we would be so simple we couldn't. — Lyall Watson

Actually , there's an article published on codeproject about that library Controlling a Barcode Reader with POS for .NET[^]
But it seems that has problems with barcode readers that are configured as a keyboard. I don't know what configuration should I make to use it.

To me that library is a MS documentation fail. It's not clear to me if it would simplify reading from a barcode scanner at all, with keyboard emulation or without. Instead it's something about "managing" POS devices, something I don't need if I just want to read from a barcode scanner. The Demo-App in the SDK doesn't clear things up either; I guess you already have to be an experienced POS developer to know what's what there. So for simply reading from a barcode scanner I would use the approach from the CodeProject article I linked before. It does all I need, does it well and the article explains what's going on there.

If the brain were so simple we could understand it, we would be so simple we couldn't. — Lyall Watson

Ok , the article that you are suggesting to use , is going to work with all kind of barcode readers , or only with those that are configured as Keyboards ?

The intended purpose of that article is to being able to know from which keyboard device a keypress came from. So it only works for barcode scanners with keyboard emulation. To my knowledge, that's probably all scanners in the price range up to $500 give or take. I haven't dealt with more expensive scanners yet.

If the brain were so simple we could understand it, we would be so simple we couldn't. — Lyall Watson

Searching on google , I've found an article that speak for my problem :
Distinguishing Barcode Scanners from the Keyboard in WinForms[^]

Do you think they are the same with your article, because I look something different.

He writes that the CodeProject article was his starting point. So it's mostly the same thing (Raw Input API); but I haven't read it all yet so I can't say if it's in some way better than the solution of the CP article or not.

If the brain were so simple we could understand it, we would be so simple we couldn't. — Lyall Watson

bonjour à Tous,
sa fait longtemps que je cherche du code pour imprimer mon DataGridView complet avec visual basic 2010 express et j'ai testé tous les codes qu'ils s'affichent avec des recherches sur google mais en vain.
Mais finalement, j'ai trouver un code c# que j'ai converti en VB qui me convient parfaitement mais le seul problème c qu'il boucle infiniment ( boucle infini au niveau du nombre de pages )
NB: Le code ne génère aucune erreur
Voici mon code :

VB.NET

Private Sub PrintDocument1_PrintPage(ByVal sender As System.Object, ByVal e As System.Drawing.Printing.PrintPageEventArgs) Handles PrintDocument1.PrintPage

VB.NET

Try
            Dim iHeaderHeight As Double
            'Set the left margin
            Dim iLeftMargin As Integer = e.MarginBounds.Left
            'Set the top margin
            Dim iTopMargin As Integer = e.MarginBounds.Top
            'Whether more pages have to print or not
            Dim bMorePagesToPrint As Boolean = False
            Dim iTmpWidth As Integer = 0
            'For the first page to print set the cell width and header height
            If bFirstPage Then
                For Each GridCol As DataGridViewColumn In DataGridView_impot.Columns
                    iTmpWidth = CType(Math.Floor(CType((CType(GridCol.Width, Double) / (CType(iTotalWidth, Double) * (CType(iTotalWidth, Double) * (CType(e.MarginBounds.Width, Double) / CType(iTotalWidth, Double))))), Double)), Integer)
                    iHeaderHeight = (CType(e.Graphics.MeasureString(GridCol.HeaderText, GridCol.InheritedStyle.Font, iTmpWidth).Height, Integer) + 11)
                    ' Save width and height of headers
                    arrColumnLefts.Add(iLeftMargin)
                    arrColumnWidths.Add(iTmpWidth)
                    iLeftMargin = (iLeftMargin + iTmpWidth)
                Next
            End If

            'Loop till all the grid rows not get printed
            Dim iRow As Double
            While (iRow <= (DataGridView_impot.Rows.Count - 1))
                Dim GridRow As DataGridViewRow = DataGridView_impot.Rows(iRow)
                'Set the cell height
                iCellHeight = (GridRow.Height + 5)
                Dim iCount As Integer = 0
                'Check whether the current page settings allows more rows to print
                If (iTopMargin + (iCellHeight >= (e.MarginBounds.Height + e.MarginBounds.Top))) Then
                    bNewPage = True
                    bFirstPage = False
                    bMorePagesToPrint = True
                    Exit While
                Else
                    If bNewPage Then
                        'Draw Header => raison sociale
                        e.Graphics.DrawString(Me.lbl_rs.Text, New Font(DataGridView_impot.Font, FontStyle.Bold), Brushes.Black, e.MarginBounds.Left, (e.MarginBounds.Top - (e.Graphics.MeasureString(Me.lbl_rs.Text, New Font(DataGridView_impot.Font, FontStyle.Bold), e.MarginBounds.Width).Height - 13)))
                        'Draw Date => date system
                        e.Graphics.DrawString(Me.lbl_date_now.Text, New Font(DataGridView_impot.Font, FontStyle.Bold), Brushes.Black, (e.MarginBounds.Left + (e.MarginBounds.Width - e.Graphics.MeasureString(Me.lbl_date_now.Text, New Font(DataGridView_impot.Font, FontStyle.Bold), e.MarginBounds.Width).Width)), (e.MarginBounds.Top - (e.Graphics.MeasureString(Me.lbl_rs.Text, New Font(New Font(DataGridView_impot.Font, FontStyle.Bold), FontStyle.Bold), e.MarginBounds.Width).Height - 13)))
                        'Draw Columns                 
                        iTopMargin = e.MarginBounds.Top
                        For Each GridCol As DataGridViewColumn In DataGridView_impot.Columns
                            e.Graphics.FillRectangle(New SolidBrush(Color.LightGray), New Rectangle(CType(arrColumnLefts(iCount), Integer), iTopMargin, CType(arrColumnWidths(iCount), Integer), iHeaderHeight))
                            e.Graphics.DrawRectangle(Pens.Black, New Rectangle(CType(arrColumnLefts(iCount), Integer), iTopMargin, CType(arrColumnWidths(iCount), Integer), iHeaderHeight))
                            e.Graphics.DrawString(GridCol.HeaderText, GridCol.InheritedStyle.Font, New SolidBrush(GridCol.InheritedStyle.ForeColor), New RectangleF(CType(arrColumnLefts(iCount), Integer), iTopMargin, CType(arrColumnWidths(iCount), Integer), iHeaderHeight), strFormat)
                            iCount = (iCount + 1)
                        Next
                        bNewPage = False
                        iTopMargin = (iTopMargin + iHeaderHeight)
                    End If

                    iCount = 0
                    'Draw Columns Contents
                    For Each Cel As DataGridViewCell In GridRow.Cells
                        If (Not (Cel.Value) Is Nothing) Then
                            e.Graphics.DrawString(Cel.Value.ToString, Cel.InheritedStyle.Font, New SolidBrush(Cel.InheritedStyle.ForeColor), New RectangleF(CType(arrColumnLefts(iCount), Integer), CType(iTopMargin, Single), CType(arrColumnWidths(iCount), Integer), CType(iCellHeight, Single)), strFormat)
                        End If

                        'Drawing Cells Borders 
                        e.Graphics.DrawRectangle(Pens.Black, New Rectangle(CType(arrColumnLefts(iCount), Integer), iTopMargin, CType(arrColumnWidths(iCount), Integer), iCellHeight))
                        iCount = (iCount + 1)
                    Next
                End If

                iRow = (iRow + 1)
                iTopMargin = (iTopMargin + iCellHeight)

            End While

            'If more lines exist, print another page.
            If bMorePagesToPrint Then
                e.HasMorePages = True
            Else
                e.HasMorePages = False
            End If

        Catch exc As Exception
            MessageBox.Show(exc.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
        End Try


    End Sub

This is an English-language site. Please edit your question and post it in English.

Ceci est un site de langue anglaise. S'il vous plaît modifier votre question et l'afficher en anglais.
(Google Translate[^])

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Good morning,
Thank you Rechard Smile | :)

i'm sorry, I didn't make attention to the used language
I will repost it in English Smile | :)

Hi Everyone, My xml looks like this, a single node with attributes.

<?xml version="1.0" encoding="utf-8"?>
<!--Project Time Tracking-->
<TimeTracking>
  <Ticket Client="150-338" Code="Overview" Call="33685" Start_Time="1/12/2015 10:04:56 AM" Stop_Time="1/12/2015 2:09:04 PM" TimeNote="">04:04:08</Ticket>
  <Ticket Client="602-501" Code="Post Go-Live Questions" Call="33480" Start_Time="1/13/2015 2:00:47 PM" Stop_Time="1/13/2015 2:30:48 PM" TimeNote="rate issues">00:30:01</Ticket>
  <Ticket Client="150-315" Code="Post Go-Live Questions" Call="32641" Start_Time="1/13/2015 3:15:12 PM" Stop_Time="1/13/2015 4:45:12 PM" TimeNote="QualityOutsource issues">01:30:00</Ticket>
</TimeTracking>

My DataGridView is named Datagridview2 and is populated from a serious of different subs, below is an example:

    Private Sub SelectedCode()
        If Not String.IsNullOrEmpty(Me.cboTimeCode.Text) Then
            DataGridView2.Columns.Clear()
            DataGridView2.Rows.Clear()
            Dim doc As New XmlDocument()
            doc.Load("c:\myBSG\myBSGTimeclock.xml")

            Dim nodeList As XmlNodeList
            Dim node As XmlNode = Nothing
            Dim selCode As String = Me.cboTimeCode.SelectedItem
            nodeList = doc.SelectNodes(".//TimeTracking/Ticket[@Code='" & selCode & "']")

            DataGridView2.Columns.Add("Client", "Client")
            DataGridView2.Columns.Add("Call", "Call")
            DataGridView2.Columns.Add("Code", "Code")
            DataGridView2.Columns.Add("TimeNote", "TimeNote")
            DataGridView2.Columns.Add("Start_Time", "Start")
            DataGridView2.Columns.Add("Stop_Time", "End")
            DataGridView2.Columns.Add("Duration", "Duration")
            For Each node In nodeList
                If InDateRange(node.Attributes("Start_Time").InnerText) = True Then
                    DataGridView2.Rows.Add(node.Attributes("Client").InnerText, node.Attributes("Call").InnerText, node.Attributes("Code").InnerText, node.Attributes("TimeNote").InnerText, node.Attributes("Start_Time").InnerText, node.Attributes("Stop_Time").InnerText, node.InnerText)

                End If
            Next
            DataGridView2.Sort(DataGridView2.Columns(4), System.ComponentModel.ListSortDirection.Descending)
end sub

Now In my grid I have editmode set to EditonKeystrokeorF2 and am wanting to edit one or more cells in a "row" and using CellEndEdit, save the edited cell (or entire row) I cannot find any samples to help me with the save code.. I was thinking it would be something easy like WriteXML but that doesnt work

Any help or direction you could offer would be great. I am thinking that my problem might be that I am using nodes with multiple attributes rather that nodes with separate elements, but my lingo and thought process may be way off.

Thanks

modified 25-Jan-16 10:00am.

Hi,
I'm trying to set the Primary Display...without success!
Here's the code I'm working on, would you please help me see what I'm doing wrong there?
There's no compilation error...it simply doesn't give the expected result!
Thank you!!

VB

Imports System.Runtime.InteropServices
Class MainWindow
    Const CCDEVICENAME As Short = 32
    Const CCFORMNAME As Short = 32
 
    Private Const MONITORINFOF_PRIMARY As Integer = &H1
    Private Const DISPLAY_DEVICE_ATTACHED_TO_DESKTOP As Integer = &H1
    Private Const DISPLAY_DEVICE_PRIMARY_DEVICE As Integer = &H4
    Private Const DISPLAY_DEVICE_MIRRORING_DRIVER As Integer = &H8
    Private Const DISPLAY_DEVICE_VGA_COMPATIBLE As Integer = &H10
    Private Const DISPLAY_DEVICE_REMOVABLE As Integer = &H20
    Private Const DISPLAY_DEVICE_MODESPRUNED As Integer = &H8000000
 
    Private Const DM_POSITION = &H20
    Private Const DM_DISPLAYORIENTATION = &H80 ' XP only
    Private Const DM_BITSPERPEL = &H40000
    Private Const DM_PELSWIDTH = &H80000
    Private Const DM_PELSHEIGHT = &H100000
    Private Const DM_DISPLAYFLAGS = &H200000
    Private Const DM_DISPLAYFREQUENCY = &H400000
    'Private Const DM_DISPLAYFIXEDOUTPUT As Long = &H20000000 ' XP only
 
    Private Const ENUM_CURRENT_SETTINGS As Integer = -1
    Private Const ENUM_REGISTRY_SETTINGS As Integer = -2
    Private Const EDS_RAWMODE As Integer = &H2
 
    Private Const CDS_UPDATEREGISTRY As Integer = &H1
    Private Const CDS_TEST As Integer = &H2
    Private Const CDS_FULLSCREEN As Integer = &H4
    Private Const CDS_GLOBAL As Integer = &H8
    Private Const CDS_SET_PRIMARY As Integer = &H10
    Private Const CDS_VIDEOPARAMETERS As Integer = &H20
    Private Const CDS_NORESET As Integer = &H10000000
    Private Const CDS_RESET As Integer = &H40000000
    Private Const CDS_FORCE As Integer = &H80000000
    Private Const CDS_NONE As Integer = 0
 
    Public Structure PointL
        Dim x As Integer
        Dim y As Integer
    End Structure
 
    <Flags()> _
    Enum DisplayDeviceStateFlags As Integer
        AttachedToDesktop = &H1
        MultiDriver = &H2
        PrimaryDevice = &H4
        MirroringDriver = &H8
        VGACompatible = &H10
        Removable = &H20
        ModesPruned = &H8000000
        Remote = &H4000000
        Disconnect = &H2000000
    End Enum
 
    '0 is Not Attached
 
    Const DISPLAY_PRIMARY_DEVICE = &H4 'Primary device
 
    'Holds the information of display adpter
    Private Structure DISPLAY_DEVICE
        Public cb As Integer
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=CCDEVICENAME)> Public DeviceName As String
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=128)> Public DeviceString As String
        Public StateFlags As Short
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=128)> Public DeviceID As String
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=128)> Public DeviceKey As String
    End Structure
 
    'Holds the setting of display adapter
    Private Structure DEVMODE
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=CCDEVICENAME)> _
        Public dmDeviceName As String
        Public dmSpecVersion As Short
        Public dmDriverVersion As Short
        Public dmSize As Short
        Public dmDriverExtra As Short
        Public dmFields As Integer
        Public dmOrientation As Short
        'Public dmPaperSize As Short
        'Public dmPaperLength As Short
        'Public dmPaperWidth As Short
        'Public dmScale As Short
        Public dmPositionX As Integer
        Public dmPositionY As Integer
        Public dmCopies As Short
        Public dmDefaultSource As Short
        Public dmPrintQuality As Short
        Public dmColor As Short
        Public dmDuplex As Short
        Public dmYResolution As Short
        Public dmTTOption As Short
        Public dmCollate As Short
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=CCFORMNAME)> _
        Public dmFormName As String
        Public dmLogPixels As Short
        Public dmBitsPerPel As Short
        Public dmPelsWidth As Integer
        Public dmPelsHeight As Integer
        Public dmDisplayFlags As Integer
        Public dmDisplayFrequency As Integer
        Public dmICMMethod As Integer
        Public dmICMIntent As Integer
        Public dmMediaType As Integer
        Public dmDitherType As Integer
        Public dmReserved1 As Integer
        Public dmReserved2 As Integer
        Public dmPanningWidth As Integer
        Public dmPanningHeight As Integer
        'Public dmPosition As Point
        'Public dmPositionX As Integer
        'Public dmPositionY As Integer
    End Structure
 
    'API declaration set or get display adpter information
    <DllImport("user32.dll")> _
    Private Shared Function EnumDisplayDevices(ByVal Unused As Integer, _
    ByVal iDevNum As Short, ByRef lpDisplayDevice As DISPLAY_DEVICE, ByVal dwFlags As Integer) As Integer
    End Function
 
    <DllImport("user32.dll")> _
    Private Shared Function EnumDisplaySettings(ByVal lpszDeviceName As String, _
    ByVal iModeNum As Integer, ByRef lpDevMode As DEVMODE) As Integer
    End Function
 
    <DllImport("user32.dll")> _
    Private Shared Function ChangeDisplaySettingsEx(ByVal lpszDeviceName As String, _
    ByRef lpDevMode As DEVMODE, ByVal hWnd As Integer, ByVal dwFlags As Integer, _
    ByVal lParam As Integer) As Integer
    End Function
    <DllImport("user32.dll")> _
    Private Shared Function ChangeDisplaySettingsEx(ByVal lpszDeviceName As String, _
    ByRef lpDevMode As IntPtr, ByVal hWnd As Integer, ByVal dwFlags As Integer, _
    ByVal lParam As Integer) As Integer
    End Function
 
Public Sub SetAsPrimaryMonitor(id As UInteger)
        Dim device = New DISPLAY_DEVICE()
        Dim deviceMode = New DEVMODE()
        device.cb = Marshal.SizeOf(device)
 
        EnumDisplayDevices(Nothing, id, device, 0)
        EnumDisplaySettings(device.DeviceName, -1, deviceMode)
        Dim offsetx = deviceMode.dmPositionX
        Dim offsety = deviceMode.dmPositionY
        deviceMode.dmPositionX = 0
        deviceMode.dmPositionY = 0
 
        ChangeDisplaySettingsEx(device.DeviceName, deviceMode, 0, (CDS_SET_PRIMARY Or CDS_UPDATEREGISTRY Or CDS_NORESET), 0)
 
        device = New DISPLAY_DEVICE()
        device.cb = Marshal.SizeOf(device)
 
        ' Update remaining devices
        Dim otherid As UInteger = 0
        While EnumDisplayDevices(Nothing, otherid, device, 0)
 
            If device.StateFlags = DisplayDeviceStateFlags.AttachedToDesktop AndAlso otherid <> id Then
                device.cb = Marshal.SizeOf(device)
                Dim otherDeviceMode = New DEVMODE()
 
                EnumDisplaySettings(device.DeviceName, -1, otherDeviceMode)
 
                otherDeviceMode.dmPositionX -= offsetx
                otherDeviceMode.dmPositionY -= offsety
 
                ChangeDisplaySettingsEx(device.DeviceName, otherDeviceMode, 0, (CDS_UPDATEREGISTRY Or CDS_NORESET), 0)
            End If
 
            device.cb = Marshal.SizeOf(device)
            otherid += 1
        End While
 
        ' Apply settings
        ChangeDisplaySettingsEx(Nothing, 0, 0, CDS_NONE, 0)
    End Sub
 
    Private Sub Button1_Click_1(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles Button1.Click
        SetAsPrimaryMonitor(0)
    End Sub
End Class

modified 19-Jan-16 5:55am.

Well did you step through it in the debugger and check the return values from the functions that do the work?

You need to narrow it down to exactly which function call is not working as intended.

The difficult we do right away...
...the impossible takes slightly longer.

It returns a 0 (DISP_CHANGE_SUCCESSFUL) !!

Did you study the documentation?

ChangeDisplaySettingsEx function (Windows)[^]

The difficult we do right away...
...the impossible takes slightly longer.

So I'm working on my Windows Service that sends email, in which I can read and write the parameters needed for it to communicate now.

I rewrote the service from scratch, and made 3 thread classes.
So the service runs Thread1 to test for communications and file I/O success.
Next Thread2 runs and check for jobs, if there are no jobs, it just sleeps for 15 minutes and checks again.
Finally, the jobs must be sent by Thread3 or the Await Task.

I've never done this before, this is my first time, and I want to get it right.
I did read an article about race conditions, so I can avoid that, and the principles of Threading
http://visualbasic.about.com/od/usingvbnet/a/threadingintro.htm[^]

Thread1 - Test for Communications, Sort of a systems check, Service Stops on failure.
Thread2 - Check for Jobs, if jobs exist, send email
Thread3 - Send Email
Await Task - Send Email

Now if there are jobs, I load the job and run it.

Question:
Is is stupid to load Thread3 to send the job from Thread2? Another Thread called from a Thread.
I did figure out how to stop the threads on shutdown or power down, and sleep. But I'm not sure what the best design would be.

Or should I just use Thread2 to load an Await Task, and have Thread2 monitor the progress, and wait for the Task to complete. Then Thread2 can load the next job if it exist and repeat the process again.

[Edit]
Now I have another question:
I have this thread base code that seemed pretty practical, used an online example.
I placed my job checking code in RunScheduler, and was going to place code to send the emails in StartWorkerThread. I don't get the RunPayLoad. What is Payload Code?

Public Class serviceThread_Jobs_BaseCode

    Public Shared ServiceThread As Thread
    Public Shared ThreadRunning As Boolean = True
    Public Shared KeepRunning As Boolean = True

    Private Shared PollingInterval As Integer = My.Settings.PollingInterval
    Private Shared ActionInterval As Integer = My.Settings.ActionInterval

    Public Shared Sub Thread_Start()

        ServiceThread = New Thread(AddressOf RunScheduler)
        ServiceThread.Name = "serviceThread_Jobs_BaseCode"
        ServiceThread.Start()

        KeepRunning = True
        custom_eventLog.WriteToEventLog("serviceThread_Jobs_BaseCode - Thread_Start() has been called", 7100, EventLogEntryType.Information)

    End Sub
    Public Shared Sub Thread_Stop()

        KeepRunning = False

        custom_eventLog.WriteToEventLog(
            "serviceThread_Jobs_BaseCode is stopping. " & vbCrLf & _
            "Please note: the worker process will live on for up to " & _
            PollingInterval / 1000 & " seconds before it terminates.",
            7100
        )

    End Sub
    Private Shared Sub RunPayload(ByVal objInput As Object)

        ' Write your service payload code and/or function calls here. For example:
        Try

            custom_eventLog.WriteToEventLog("serviceThread_Jobs_BaseCode - payload execution: " & objInput, 7100)

        Catch e As Exception

            custom_eventLog.WriteToEventLog("serviceThread_Jobs_BaseCode - payload execution error: " & e.Message & vbCrLf, 7200)

        End Try

    End Sub
    Private Shared Sub RunScheduler()

        Dim LastActionTime As Date = DateAdd(DateInterval.Day, -1, Date.Now)
        Do While KeepRunning

            If DateDiff(DateInterval.Second, LastActionTime, Date.Now) >= ActionInterval Then

                LastActionTime = Date.Now

                'check for posted jobs

                StartWorkerThread()

            End If

            Thread.Sleep(PollingInterval)

        Loop

    End Sub
    Private Shared Sub StartWorkerThread()

        'Check for the Thread Stop Command and Stop Running
        If (True = KeepRunning) Then

            Dim WorkerThread As Thread = New Thread(AddressOf RunPayload)

            ' A parameter value can be transferred to the payload function via Start():
            WorkerThread.Start("Hello world " & Date.Now.ToString("yyyy-MM-dd HH:mm:ss"))

        Else

            ThreadRunning = False

        End If

    End Sub

End Class

modified 14-Jan-16 14:09pm.

From your description it's not obvious to me why you need parallelism at all. Couldn't you just make do with a single thread that completes these steps in sequence?

If the brain were so simple we could understand it, we would be so simple we couldn't. — Lyall Watson

The 2nd version I wrote does it in a single task in my Windows Form App using await.

And the first version I wrote of this Windows Service does it using Main()
But the Code looked sort of sloppy and relied too heavily on timers, so I thought I'd try something different.

I guess I just wanted to learn how to use threads, and wanted to implement it in this program.

modified 14-Jan-16 14:38pm.

That code is using a whole thread just for the purpose of starting another thread at regular intervals and otherwise sleeping. That's awful. You could basically replace it with the code sample from the Timer Class (System.Threading)[^].

If you got a working code without threading I would use that. If it looks sloppy (like you said) I would suggest trying to improve it without introducing unnecessary parallelism. If you want to do something with Tasks/Threads in order to learn about it I would try to find some project that actually calls for it.

And I would suggest using Tasks instead of Threads: Tasks can do the same thing but better/in a more convenient way in 99% of all cases. Take a look at Sacha Barber's articles on the TPL if you haven't already: Task Parallel Library: 1 of n[^]

If the brain were so simple we could understand it, we would be so simple we couldn't. — Lyall Watson

I'm starting to get it now. Advice taken

Assuming you're sending out a (fairly) large number of emails (if not, why bother with this at all?) I think you'd do better to, as others have suggested, write it in a single thread, but then use multi-threading for the actual sending - you can send out multiple emails faster by, for example, looping through your mails and sending each out via one of, say, three threads in turn.

I went back to the single thread yesterday, and converted my threads to Await or Async. The part that sends the email is threaded already, using Thread and ThreadStart. I mange to run one test yesterday, and so far so good, it worked. Just need to plug in the sending part and test again.

Right now, the subscriber list has about 4000 people, so with a 5 second pause, it doesn't take long to send the list, about 4 hours. And they all go to the same mailserver for sending.

Well for what its worth, at least I have some experience with it, and will be ready if that day ever comes.

I'll probably be back for the stop question, if the cancellation token doesn't work for shutting down the service, and I need to figure how how to save the position of the subscriber list, to pick up where it left off.

But Thanks for the real work view for the proper design aspect!

Yup - nothing like learning the hard way!

Do you really need a 5 second pause between mails? Maybe it depends on your mail server/service, but it shouldn't really be necessary. I've sent to lists of c 4,000 in a fraction of the time yours are taking - talking minutes, not hours - using 3 threads in the sending routine.

The idea behind that was to allow time for other things;

Be nice to the mail server at the customers ISP, instead of bombarding it, just do a slow feed.
Allow time for people using the website to squeeze in a page request.

I was thinking of that Russian search engine Yandex that just goes full force on my web servers, and didn't want to be like that.

I just reread this, your using 3 threads? Smile | :)

I do compress the HTML before sending to make a smaller package.

Well, you have a different model from me; in my case, I'm hosting the client websites, and my mail program runs as an exe in the background regularly polling their databases to see if they've initiated a mailout. When it finds one, it cycles through their mailing-list/s and sends out their newsletter, using a 3-threaded routine. The emails are sent using a third-party email relay service - my exe simply creates the mail messages and fires them off using this relay service. It's very quick, and doesn't impact on the sites' performance in any noticeable way.