Problem with running a windows service in vb.net

[sohaib_a]

I have a windows a service that periodically checks the tcp/ip connection of device by pinging it and returning the status. So for this i have used a timer.At first i tried to to dynamically create a timer using System.Timers.Timer and using the 'Elapsed'event.But the when i tried to start the service it wouldn't start. Then I used a timer from the toolbox and seemed to start fine,the code in onstop and onstart subs is executing.However the code in timer_tick event isn't.I don't know why.I start the timer in the onstart and stop it onstop. Below is code for the timer event.

Private Sub Timer2_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer2.Tick

    Dim api As New RfidApiLib.RfidApi
    Dim status1 As Integer

    Dim StrCon As String
    Dim conn As SqlConnection
    Dim host As String
    'Dim status1 As Integer
    test.WriteByDate("e:\\temp", "log", "service", "reader timer this connected") ' Writes to log file
    'mylog.WriteEntry("Connected", EventLogEntryType.Information)

    StrCon = "data source=XXX;initial catalog=XXX; uid=XXX; pwd=XXX;"
    conn = New SqlConnection(StrCon)

    conn.Open()

    Dim outadapter1 As New SqlDataAdapter("select \* from dbo.ReaderInfo where dbo.ReaderInfo.Reader\_location in (Select Reader\_location from dbo.Reader\_Status )", conn)
    Dim ds1 As New DataSet()
    outadapter1.Fill(ds1, "dbo.ReaderInfo")

    Dim outadapter2 As New SqlDataAdapter("Select \* from dbo.Reader\_Status where Remarks = 'C'", conn)
    Dim ds2 As New DataSet()
    outadapter1.Fill(ds2, "dbo.ReaderInfo")

    For i As Integer = 0 To ds2.Tables(0).Rows.Count - 1

        host = ds1.Tables(0).Rows(i)("ReaderIP").ToString
        Try
            'My.Computer.Network.Ping(host)
            Dim ping As New System.Net.NetworkInformation.Ping()
            Dim pingReply As System.Net.NetworkInformation.PingReply = ping.Send(host) 'ping ipaddress

            'test.WriteByDate("e:\\temp", "log", "service", "reader" & ds1.Tables(0).Rows(i)("Reader\_location").ToString & "disconnected" & e1.Message)

        Catch e1 As System.Net.NetworkInformation.PingException 'if not connected try reconnecting

            status1 = api.TcpConnectReader(ds1.Tables(0).Rows(i)("ReaderIP").ToString, ds1.Tables(0).Rows(i)("ReaderPort")) 'API call to connect to device

            If status1 = 0 Then ' successfully connected

[Dave Kreskowiak]

Your post isn't readable because it's too wide. Break the code sample lines into multiple lines to reduce the width of the post. From the limited information I got from your post (what I could read anyway), you used the Timer control in the ToolBox and dropped it on a Form?? This isn't going to work in a service because there is no message pump. In a service, you would normally use the System.Threading.Timer, which makes direct calls back to your code instead of using events.

A guide to posting questions on CodeProject[^]
Dave Kreskowiak Microsoft MVP Visual Developer - Visual Basic
     2006, 2007, 2008

modified on Wednesday, January 7, 2009 2:20 PM

[programmervb netc]

Try using the Timer.Elapsed event instead and set the amount of time in the properties for the timer control.

Humble Programmer

[Tim Carmichael]

The service I have has a timer (System.Timers.Timer) that works. Searching for help on this class should point you in the right direction. Tim

[sohaib_a]

ok it worked using the system.threading.timer class.Apparently the other two timers dont work in windows service in .net 2.0.read it online. I want to know more what this timer does.I searched online and what I figured is that it similar to the forms timer except that the timer event runs in a different thread using timercallback delegate. So is it something like a thread that runs periodically?