ping using vb-

Sorry for new thread--i have this code,basically a loop to ping a list of ip's return the results and save them to an access db:

Code:

---

Public Class SwitchMonitor
    Dim Ping As Net.NetworkInformation.Ping
    Dim pReply As Net.NetworkInformation.PingReply



    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim i As Integer
        Dim ds As New DataSet
        Dim da As OleDb.OleDbDataAdapter
        Dim sql As String
        Dim con As New OleDb.OleDbConnection

        Label1.Visible = True    'sets the visible properties to advice labels that display after clicking ping button
        Label2.Visible = True
        Label3.Visible = True
        Label4.Visible = True

        con.ConnectionString = "PROVIDER=Microsoft.Jet.OLEDB.4.0;Data Source = C:\Documents and Settings\mhorgan\Desktop\Network Map.mdb"
        con.Open()

        sql = "SELECT * FROM tblSwitch"
        da = New OleDb.OleDbDataAdapter(sql, con)
        da.Fill(ds, "monitor")

        Dim cb As New OleDb.OleDbCommandBuilder(da)
        Ping = New Net.NetworkInformation.Ping
        Dim dgvr As DataGridViewRow

        ProgressBar1.Minimum = 0                                      'sets minimum value of progress bar
        ProgressBar1.Maximum = ds.Tables("monitor").Rows.Count - 1    'sets maximum value of progress bar

        For i = 0 To ds.Tables("monitor").Rows.Count - 1

            Application.DoEvents()

            ' Set up the progress bar's properties
            ProgressBar1.Value = i


            dgvr = New DataGridViewRow      'Creates a new row           
            DataGridView1.Rows.Add(dgvr)    'Add the row           

            Try

                pReply = Ping.Send(ds.Tables("monitor").Rows(i).Item(5)) 'Sends the ping to the current item               


                DataGridView1.Rows.Item(i).Cells(0).Value = ds.Tables("monitor").Rows(i).Item(1) 'read in switch name from column 2 in network map db

                DataGridView1.Rows.Item(i).Cells(1).Value = ds.Tables("monitor").Rows(i).Item(5) 'Updates the value of the new Item               

                DataGridView1.Rows.Item(i).Cells(2).Value = pReply.Status  'The value of the status returned               

                DataGridView1.Rows.Item(i).Cells(3).Value = Now.ToString() 'show the last time checked with Now.ToString() method


                If pReply.Status <> Net.NetworkInformation.IPStatus.Success Then  'Sets the color of the cell based on ping result       

                    DataGridView1.Rows.Item(i).Cells(2).Style.BackColor = Color.Red
                Else
                    DataGridView1.Rows.Item(i).Cells(2).Style.BackColor = Color.Green
                End If

                ds.Tables("monitor").Rows(i).Item(6) = pReply.Status    'Write in the original datatable
                ds.Tables("monitor").Rows(i).Item(7) = Now.ToString()  'added code for date/time
                da.Update(ds, "monitor") 'Updates the database


            Catch ex As Exception        'Error Handling
                MessageBox.Show(ex.ToString())
            End Try
        Next

    End Sub


    Private Sub btnExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click
        Dim con As New OleDb.OleDbConnection
        con.ConnectionString = "PROVIDER=Microsoft.Jet.OLEDB.4.0;Data Source = C:\Documents and Settings\mhorgan\Desktop\Network Map.mdb"
        con.Close()
        End
    End Sub

    Private Sub SwitchMonitor_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub

End Class

---

The problem is that for some reason when i first run the code in the morning all the switches time out and as there are over 400 switches this takes over 25mins during which the program remains unresponsive, but if i then run the code a second time it works perfectly and all the switches that are up ping back and it only takes around 4mins (the reason it takes 4mins is because there are a number of switches in the db which i know are down and each of these take 5secs to time out). Its as if the program needs a warm up run ? anyone able to offer an explanation ?? - i have been told to use multiplethreads and background threads but im new to coding and my skills are very limited so im hoping if im just able to identify the problem i might be able to find an easier way around it-besides from what i gather the two suggestions mentioned above will only speed up the program which is not what im looking for,im just wondering WHY the code behaves differently the first time i run it ??-cant figure it out would appreciate any ideas cheers

I wrote some code that does async pings and then just handles the responses, instead of waiting for each ping reply to come in 1 by 1.

You should be able to adapt it to your needs.

http://www.vbforums.com/showthread.php?t=573829

I could have sworn I showed you how to do it using background threads last time you posted this same question. In fact I even remember taking the time to create an example database and complete working example program... did I dream that?

EDIT: http://www.vbforums.com/showthread.php?t=577053

i know chris you did and thank you for that and i tried adapting it to my project but failed miserably , but for the moment im not so much looking for a solution to the problem im just looking for the CAUSE of the problem , why does the program need to run through once before it behaves correctly

im guessing that some procedure needs to be run only the first time the code runs(or for some reason takes longer the first time) and this takes longer than 5secs(as all ips time-out) , is it the pinging itself ? the datagridview ? vb loading the dataset ??-dataset is quite large 500+entries the fact that it is such a long procedure with only very basic coding operating in a single thread ?? - im guessing its the latter as everyone is suggesting background/multiplethreads but id like to identify the problem before i try and solve it.

any idea what this procedure might be ??

ive taken another look at that post chris and the error im getting is at this line:

UpdateCommand.ExecuteNonQuery() 'Execute the command that updates the database

and it reads: No value given for one or more required parameters.

the db was never attatched so i had to make my own, im also trying to make sure its not a mismatch of data types i have tried changing result from bolean to string as all i could use in the access db was yes/no which i didnt think would be compatible with type bolean
also i have changed ipaddress to IP (the column name in the pingDB)

The Yes/No type in Access is the same as Boolean.

That message you are getting means that you have specified a command string that has a parameter in it but then havent assigned a value for that parameter. So for example in this code:

vb Code:

Dim UpdateCommand As New OleDBCommand("UPDATE sometable SET column1=@parameter1 WHERE column2=@parameter2", MyConnection)

the @parameter1 and @parameter2 bits are parameters that it is expecting you to fill with a value, and to do that you have to do something like this (off the top of my head so syntax may not be 100% correct):

vb Code:

UpdateCommand.Parameters.Add("@parameter1", Boolean).Value = True

then the same for @parameter2.
So go through the code you are using and look for any command strings that are using parameters and make sure you fill all of those with the relevant values before you call ExecuteNonQuery

you werent far off...

UpdateCommand.Parameters.Add("@parameter1", OleDbType.Boolean).Value = True

runs now, is very fast too results show up in logbox, one problem though it doesnt update the db. any ideas ? -im only familiar with connections using datasets so im kinda lost when it comes to your code

it reads in perfectly from db so its not a problem with the connection or anythin like its gotta be solely to do with the update commands, il try play around with them in the mean time

Have you got the Access database open when you run it? I think that would stop it writing to the database

no thats not it i had it closed while i was running it

i also had to change select IP,ID to select * but i dont think this should make a difference !

so is it working now?

well it runs perfectly but it only reads the ip's from the db ,unfortunately it doesnt write the result or the current time to the db which is the most important part for the project im working on , must be the update commands , was it working when you made it with your sample db ?

Yeah it was definitely working with my test database, reading from it and updating it with the results.

Can you post the code you are using now and list the columns you have in your database and their types?

heres code:

Code:

---

Imports System.Data.OleDb

Public Class Form1

    ''' <summary>
    ''' Represents a network switch (or any device with an IP) that is in the database
    ''' </summary>
    Private Class NetworkSwitch
        Private _IPAddress As String
        Private _ID As Integer
        Private _Result As Boolean

        Public Property IPAddress() As String
            Get
                Return _IPAddress
            End Get
            Set(ByVal value As String)
                _IPAddress = value
            End Set
        End Property

        Public Property ID() As Integer
            Get
                Return _ID
            End Get
            Set(ByVal value As Integer)
                _ID = value
            End Set
        End Property

        Public Property Result() As Boolean
            Get
                Return _Result
            End Get
            Set(ByVal value As Boolean)
                _Result = value
            End Set
        End Property

    End Class

    'Set up some variables that we will use from various functions/subs
    Private PingList As List(Of NetworkSwitch)
    Private Counter As Integer = 0
    Private ConnString As New OleDbConnectionStringBuilder("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\test\pingDB.mdb;User Id=admin;Password=;")
    'This is the Delegate that will be used to pass data between the threads safely
    Private Delegate Sub PingComplete(ByVal sw As NetworkSwitch)

    Private Sub Pingbtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Pingbtn.Click
        Counter = 0 'reset the counter in case this is not the first time the ping button has been clicked
        Pingbtn.Enabled = False  'Disable the ping button so it cannot be pressed again yet
        btnExit.Enabled = False
        Dim bgthread As New Threading.Thread(AddressOf BG_CollectData)  'Create a new background thread
        bgthread.IsBackground = True  'Make the thread end if the program is closed
        bgthread.Start()  'Start the background thread
    End Sub

    ''' <summary>
    ''' This is the routine that is executed when bgthread.Start() is called in the event handler above
    ''' It collects information from the Access database and stores it in a list, then kicks off another
    ''' background thread (from the ThreadPool) that sends the ping
    ''' </summary>
    Private Sub BG_CollectData()
        'Create our connection that will be used to connect to the Access database
        Dim AccessConnection As New OleDbConnection(ConnString.ConnectionString)

        'Create the command that will be used to select all of the data in the IP and ID columns
        Dim SelectCommand As New OleDbCommand("SELECT * FROM PingTable", AccessConnection)

        'Create a new instance of a list of our NetworkSwitch class
        PingList = New List(Of NetworkSwitch)

        'Open the connection to the database
        AccessConnection.Open()

        'Use a DataReader to access the data that the SELECT command returns
        Dim Reader As OleDbDataReader = SelectCommand.ExecuteReader
        'Start to loop through the results
        'This loop will be restarted for each row in the database
        Do While Reader.Read
            'Create a new instance of our NetworkSwitch class and populate the ID and IP properties
            'with data from the current row in the database that we are looping through
            Dim CurrentSwitch As New NetworkSwitch
            With CurrentSwitch
                .ID = Reader("ID")
                .IPAddress = Reader("IPAddress")
            End With
            'Add the new instance of the NetworkSwitch to our list
            PingList.Add(CurrentSwitch)
        Loop 'Start the loop again for the next record in the database

        'Close the connection because we have now processed all rows in the database
        AccessConnection.Close()

        'Give the threadpool a limit so that no more than 30 threads are running at the same time
        Threading.ThreadPool.SetMaxThreads(30, 400)

        'Loop through our list of NetworkSwitch instances and start (well, queue up) a new background
        'thread for each item in the list and passes it the current item in the loop (which is a NetworkSwitch object)
        For Each switchobject As NetworkSwitch In PingList
            Threading.ThreadPool.QueueUserWorkItem(New Threading.WaitCallback(AddressOf DoPing), switchobject)
        Next
    End Sub

    ''' <summary>
    ''' Performs the ping and updates the Result property of the NetworkSwitch object that was passed to this
    ''' </summary>
    Private Sub DoPing(ByVal Switch As NetworkSwitch)
        Dim Result As Net.NetworkInformation.PingReply
        Dim SendPing As New Net.NetworkInformation.Ping
        Result = SendPing.Send(Switch.IPAddress)
        If Result.Status = Net.NetworkInformation.IPStatus.Success Then
            Switch.Result = True
        Else
            Switch.Result = False
        End If
        UpdateDatabase(Switch)
        Counter += 1
        Me.Invoke(New PingComplete(AddressOf UI_PingComplete), Switch)
    End Sub

    ''' <summary>
    ''' This is executed each time a ping completes and the database has been updated.
    ''' It is executed on the UI thread because we used Me.Invoke to call it so it can access
    ''' controls on the UI thread without a problem
    ''' </summary>
    Private Sub UI_PingComplete(ByVal sw As NetworkSwitch)
        logbox.AppendText(sw.IPAddress & " ping complete - " & sw.Result & vbNewLine) 'update our log textbox
        If Counter = PingList.Count Then
            logbox.AppendText("Finished all tests" & vbNewLine)
            Pingbtn.Enabled = True 're-enable the ping button
            btnExit.Enabled = True
            PingList = Nothing 'clean up
        End If
    End Sub

    ''' <summary>
    ''' Updates the relevant row in the database for the switch that is passed to this method
    ''' </summary>
    Private Sub UpdateDatabase(ByVal sw As NetworkSwitch)
        Dim AccessConnection As New OleDbConnection(ConnString.ConnectionString)
        Dim UpdateCommand As New OleDbCommand("UPDATE PingTable SET Result=@Result, LastTested=@CurrentTime WHERE ID=@ID", AccessConnection)
        With UpdateCommand.Parameters
            .Add("@Result", OleDbType.Boolean).Value = sw.Result
            .Add("@CurrentTime", OleDbType.Char).Value = Now.ToString
            .Add("@ID", OleDbType.Integer).Value = sw.ID
        End With
        AccessConnection.Open()
        UpdateCommand.Parameters.Add("@parameter1", OleDbType.Boolean).Value = True'Execute the command that updates the database
   


        AccessConnection.Close()
    End Sub

    Private Sub btnExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click
        End
    End Sub
End Class

---

and these are all the columns in access db (access 2000 format)

ID-number
IPAddress-text
Result-Yes/no
CurrentTime-text

You are not actually executing the Update command. See in this sub:

vb Code:

''' <summary>
    ''' Updates the relevant row in the database for the switch that is passed to this method
    ''' </summary>
Private Sub UpdateDatabase(ByVal sw As NetworkSwitch)
        Dim AccessConnection As New OleDbConnection(ConnString.ConnectionString)
        Dim UpdateCommand As New OleDbCommand("UPDATE PingTable SET Result=@Result, LastTested=@CurrentTime WHERE ID=@ID", AccessConnection)
        With UpdateCommand.Parameters
            .Add("@Result", OleDbType.Boolean).Value = sw.Result
            .Add("@CurrentTime", OleDbType.Char).Value = Now.ToString
            .Add("@ID", OleDbType.Integer).Value = sw.ID
        End With
        AccessConnection.Open()
        UpdateCommand.Parameters.Add("@parameter1", OleDbType.Boolean).Value = True'Execute the command that updates the database
   AccessConnection.Close()
End Sub

Get rid of this line (because it is pointless as you are not using a parameter named @Parameter1

vb Code:

UpdateCommand.Parameters.Add("@parameter1", OleDbType.Boolean).Value = True

and replace it with this:

vb Code:

UpdateCommand.ExecuteNonQuery

Keep in mind that some ISPs block Pings due to security.
If your ISP or any other ISP for some of your users does block the Ping(s) you won't get the expected or desired results.

made that change but another error at that line when i press ping , oledbexception unhandled-No value given for one or more required parameters.

tried adding basic error handling to see if it helped
ie

Code:

---

try
Catch ex As Exception        'Error Handling
            MessageBox.Show(ex.ToString())
        End Try

---

but hasnt worked yet ,instead now im getting an error message box each time new thread sends a ping

okay nevermind ! found the problem , the access column was named currenttime instead of LastTested , can the text in the logbox be conditionally formatted like in datagridview ? ie red for false green for true ?

Yeah but to be honest you are probably just better off using a datagridview like you say

okay thanks will try that ! what about adding a progress bar ? could this be easily done ?

im guessing its something like this but not sure what to set value to, also not sure where to put code because everywhere i try i get crossthread errors ?

Code:

---

ProgressBar1.Minimum = 0    'sets minimum value of progress bar
        ProgressBar1.Maximum = Counter 'maximum value of progres

        ProgressBar1.Value = ??  ' Set up the progress bar's properties

---

also tried changing from richtextbox to datagridview but im having trouble with the loop.
heres code:

Code:

---

Imports System.Data.OleDb

Public Class Form1

    ''' <summary>
    ''' Represents a network switch (or any device with an IP) that is in the database
    ''' </summary>
    Private Class NetworkSwitch
        Private _IPAddress As String
        Private _ID As Integer
        Private _Result As Boolean

        Public Property IPAddress() As String
            Get
                Return _IPAddress
            End Get
            Set(ByVal value As String)
                _IPAddress = value
            End Set
        End Property

        Public Property ID() As Integer
            Get
                Return _ID
            End Get
            Set(ByVal value As Integer)
                _ID = value
            End Set
        End Property

        Public Property Result() As Boolean
            Get
                Return _Result
            End Get
            Set(ByVal value As Boolean)
                _Result = value
            End Set
        End Property

    End Class

    'Set up some variables that we will use from various functions/subs
    Dim i As Integer

    Private PingList As List(Of NetworkSwitch)
    Private Counter As Integer = 0
    Private ConnString As New OleDbConnectionStringBuilder("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\test\pingDB.mdb;User Id=admin;Password=;")
    'This is the Delegate that will be used to pass data between the threads safely
    Private Delegate Sub PingComplete(ByVal sw As NetworkSwitch)


    Private Sub Pingbtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Pingbtn.Click
        Counter = 0 'reset the counter in case this is not the first time the ping button has been clicked
        Pingbtn.Enabled = False  'Disable the ping button so it cannot be pressed again yet
        btnExit.Enabled = False
        Dim bgthread As New Threading.Thread(AddressOf BG_CollectData)  'Create a new background thread
        bgthread.IsBackground = True  'Make the thread end if the program is closed
        bgthread.Start()  'Start the background thread
    End Sub

    ''' <summary>
    ''' This is the routine that is executed when bgthread.Start() is called in the event handler above
    ''' It collects information from the Access database and stores it in a list, then kicks off another
    ''' background thread (from the ThreadPool) that sends the ping
    ''' </summary>
    Private Sub BG_CollectData()
        'Create our connection that will be used to connect to the Access database
        Dim AccessConnection As New OleDbConnection(ConnString.ConnectionString)

        'Create the command that will be used to select all of the data in the IP and ID columns
        Dim SelectCommand As New OleDbCommand("SELECT * FROM PingTable", AccessConnection)

        'Create a new instance of a list of our NetworkSwitch class
        PingList = New List(Of NetworkSwitch)

        'Open the connection to the database
        AccessConnection.Open()

        'Use a DataReader to access the data that the SELECT command returns
        Dim Reader As OleDbDataReader = SelectCommand.ExecuteReader
        'Start to loop through the results
        'This loop will be restarted for each row in the database
        Do While Reader.Read
            'Create a new instance of our NetworkSwitch class and populate the ID and IP properties
            'with data from the current row in the database that we are looping through
            Dim CurrentSwitch As New NetworkSwitch
            With CurrentSwitch
                .ID = Reader("ID")
                .IPAddress = Reader("IPAddress")
            End With
            'Add the new instance of the NetworkSwitch to our list
            PingList.Add(CurrentSwitch)
        Loop 'Start the loop again for the next record in the database

        'Close the connection because we have now processed all rows in the database
        AccessConnection.Close()

        'Give the threadpool a limit so that no more than 30 threads are running at the same time
        Threading.ThreadPool.SetMaxThreads(30, 400)

        'Loop through our list of NetworkSwitch instances and start (well, queue up) a new background
        'thread for each item in the list and passes it the current item in the loop (which is a NetworkSwitch object)
        For Each switchobject As NetworkSwitch In PingList
            Threading.ThreadPool.QueueUserWorkItem(New Threading.WaitCallback(AddressOf DoPing), switchobject)
        Next
    End Sub

    ''' <summary>
    ''' Performs the ping and updates the Result property of the NetworkSwitch object that was passed to this
    ''' </summary>
    Private Sub DoPing(ByVal Switch As NetworkSwitch)
        Dim Result As Net.NetworkInformation.PingReply
        Dim SendPing As New Net.NetworkInformation.Ping
        Result = SendPing.Send(Switch.IPAddress)
        If Result.Status = Net.NetworkInformation.IPStatus.Success Then
            Switch.Result = True

            ' <<<<<<----change Font Color to green/red ??
        Else
            Switch.Result = False
        End If

        UpdateDatabase(Switch)
        Counter += 1
        Me.Invoke(New PingComplete(AddressOf UI_PingComplete), Switch)
    End Sub

    ''' <summary>
    ''' This is executed each time a ping completes and the database has been updated.
    ''' It is executed on the UI thread because we used Me.Invoke to call it so it can access
    ''' controls on the UI thread without a problem
    ''' </summary>
    Private Sub UI_PingComplete(ByVal sw As NetworkSwitch)

        Dim dgvr As DataGridViewRow
        Dim i As Integer
        For i = 0 To PingList.Count

            Application.DoEvents()

            dgvr = New DataGridViewRow      'Creates a new row           
            DataGridView1.Rows.Add(dgvr)    'Add the row           





            DataGridView1.Rows.Item(i).Cells(0).Value = sw.IPAddress

            DataGridView1.Rows.Item(i).Cells(1).Value = sw.ID

            DataGridView1.Rows.Item(i).Cells(2).Value = sw.Result

            DataGridView1.Rows.Item(i).Cells(3).Value = Now.ToString() 'show the last time checked with Now.ToString() method



            '  logbox.AppendText(sw.IPAddress & " ping complete - " & sw.Result & vbNewLine) 'update our log textbox
            If Counter = PingList.Count Then
                ' logbox.AppendText("Finished all tests" & vbNewLine)
                Pingbtn.Enabled = True 're-enable the ping button
                btnExit.Enabled = True
                PingList = Nothing 'clean up
            End If
        Next
    End Sub

    ''' <summary>
    ''' Updates the relevant row in the database for the switch that is passed to this method
    ''' </summary>
    Private Sub UpdateDatabase(ByVal sw As NetworkSwitch)

        Dim AccessConnection As New OleDbConnection(ConnString.ConnectionString)
        Dim UpdateCommand As New OleDbCommand("UPDATE PingTable SET Result=@Result, LastTested=@CurrentTime WHERE ID=@ID", AccessConnection)
        With UpdateCommand.Parameters
            .Add("@Result", OleDbType.Boolean).Value = sw.Result
            .Add("@CurrentTime", OleDbType.Char).Value = Now.ToString
            .Add("@ID", OleDbType.Integer).Value = sw.ID
        End With
        AccessConnection.Open()

        UpdateCommand.ExecuteNonQuery()  'Execute the command that updates the database

        AccessConnection.Close()


    End Sub

    Private Sub btnExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click
        End
    End Sub
End Class

---

okay i think im a bit closer now but ders still a problem with the loop , or the multiple threads , or the datagridview ,

Code:

---

Imports System.Data.OleDb

Public Class Form1

    ''' <summary>
    ''' Represents a network switch (or any device with an IP) that is in the database
    ''' </summary>
    Private Class NetworkSwitch
        Private _IPAddress As String
        Private _ID As Integer
        Private _Result As Boolean

        Public Property IPAddress() As String
            Get
                Return _IPAddress
            End Get
            Set(ByVal value As String)
                _IPAddress = value
            End Set
        End Property

        Public Property ID() As Integer
            Get
                Return _ID
            End Get
            Set(ByVal value As Integer)
                _ID = value
            End Set
        End Property

        Public Property Result() As Boolean
            Get
                Return _Result
            End Get
            Set(ByVal value As Boolean)
                _Result = value
            End Set
        End Property

    End Class

    'Set up some variables that we will use from various functions/subs
    Dim i As Integer

    Private PingList As List(Of NetworkSwitch)
    Private Counter As Integer = 0
    Private ConnString As New OleDbConnectionStringBuilder("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\test\pingDB.mdb;User Id=admin;Password=;")
    'This is the Delegate that will be used to pass data between the threads safely
    Private Delegate Sub PingComplete(ByVal sw As NetworkSwitch)


    Private Sub Pingbtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Pingbtn.Click
        Counter = 0 'reset the counter in case this is not the first time the ping button has been clicked
        Pingbtn.Enabled = False  'Disable the ping button so it cannot be pressed again yet
        btnExit.Enabled = False
        Dim bgthread As New Threading.Thread(AddressOf BG_CollectData)  'Create a new background thread
        bgthread.IsBackground = True  'Make the thread end if the program is closed
        bgthread.Start()  'Start the background thread
    End Sub

    ''' <summary>
    ''' This is the routine that is executed when bgthread.Start() is called in the event handler above
    ''' It collects information from the Access database and stores it in a list, then kicks off another
    ''' background thread (from the ThreadPool) that sends the ping
    ''' </summary>
    Private Sub BG_CollectData()
        'Create our connection that will be used to connect to the Access database
        Dim AccessConnection As New OleDbConnection(ConnString.ConnectionString)

        'Create the command that will be used to select all of the data in the IP and ID columns
        Dim SelectCommand As New OleDbCommand("SELECT * FROM PingTable", AccessConnection)

        'Create a new instance of a list of our NetworkSwitch class
        PingList = New List(Of NetworkSwitch)

        'Open the connection to the database
        AccessConnection.Open()

        'Use a DataReader to access the data that the SELECT command returns
        Dim Reader As OleDbDataReader = SelectCommand.ExecuteReader
        'Start to loop through the results
        'This loop will be restarted for each row in the database
        Do While Reader.Read
            'Create a new instance of our NetworkSwitch class and populate the ID and IP properties
            'with data from the current row in the database that we are looping through
            Dim CurrentSwitch As New NetworkSwitch
            With CurrentSwitch
                .ID = Reader("ID")
                .IPAddress = Reader("IPAddress")
            End With
            'Add the new instance of the NetworkSwitch to our list
            PingList.Add(CurrentSwitch)
        Loop 'Start the loop again for the next record in the database

        'Close the connection because we have now processed all rows in the database
        AccessConnection.Close()

        'Give the threadpool a limit so that no more than 30 threads are running at the same time
        Threading.ThreadPool.SetMaxThreads(30, 400)

        'Loop through our list of NetworkSwitch instances and start (well, queue up) a new background
        'thread for each item in the list and passes it the current item in the loop (which is a NetworkSwitch object)
        For Each switchobject As NetworkSwitch In PingList
            Threading.ThreadPool.QueueUserWorkItem(New Threading.WaitCallback(AddressOf DoPing), switchobject)
        Next
    End Sub

    ''' <summary>
    ''' Performs the ping and updates the Result property of the NetworkSwitch object that was passed to this
    ''' </summary>
    Private Sub DoPing(ByVal Switch As NetworkSwitch)
        Dim Result As Net.NetworkInformation.PingReply
        Dim SendPing As New Net.NetworkInformation.Ping
        Result = SendPing.Send(Switch.IPAddress)


        If Result.Status = Net.NetworkInformation.IPStatus.Success Then
            Switch.Result = True
            DataGridView1.Rows.Item(i).Cells(2).Style.BackColor = Color.Green
            ' <<----change Font Color to green/red ??
        Else
            Switch.Result = False
            DataGridView1.Rows.Item(i).Cells(2).Style.BackColor = Color.Red
        End If

                UpdateDatabase(Switch)
                Counter += 1
                Me.Invoke(New PingComplete(AddressOf UI_PingComplete), Switch)

         
    End Sub

    ''' <summary>
    ''' This is executed each time a ping completes and the database has been updated.
    ''' It is executed on the UI thread because we used Me.Invoke to call it so it can access
    ''' controls on the UI thread without a problem
    ''' </summary>
    Private Sub UI_PingComplete(ByVal sw As NetworkSwitch)




        Dim dgvr As DataGridViewRow






            dgvr = New DataGridViewRow      'Creates a new row           
            DataGridView1.Rows.Add(dgvr)    'Add the row           

            Try

            DataGridView1.Rows.Item(i).Cells(0).Value = sw.ID 'read in switch name from column 2 in network map db
            DataGridView1.Rows.Item(i).Cells(1).Value = sw.IPAddress 'Updates the value of the new Item               
                DataGridView1.Rows.Item(i).Cells(2).Value = sw.Result  'The value of the status returned               
                DataGridView1.Rows.Item(i).Cells(3).Value = Now.ToString() 'show the last time checked with Now.ToString() method


                If Counter = PingList.Count Then

                    Pingbtn.Enabled = True 're-enable the ping button
                    btnExit.Enabled = True
                    PingList = Nothing 'clean up
                End If


            Catch ex As Exception        'Error Handling
                MessageBox.Show(ex.ToString())
            End Try


    End Sub

    ''' <summary>
    ''' Updates the relevant row in the database for the switch that is passed to this method
    ''' </summary>
    Private Sub UpdateDatabase(ByVal sw As NetworkSwitch)

        Dim AccessConnection As New OleDbConnection(ConnString.ConnectionString)
        Dim UpdateCommand As New OleDbCommand("UPDATE PingTable SET Result=@Result, LastTested=@CurrentTime WHERE ID=@ID", AccessConnection)
        With UpdateCommand.Parameters
            .Add("@Result", OleDbType.Boolean).Value = sw.Result
            .Add("@CurrentTime", OleDbType.Char).Value = Now.ToString
            .Add("@ID", OleDbType.Integer).Value = sw.ID
        End With
        AccessConnection.Open()

        UpdateCommand.ExecuteNonQuery()  'Execute the command that updates the database

        AccessConnection.Close()


    End Sub

    Private Sub btnExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click
        End
    End Sub
End Class

---

okay sorry for all the postS but i cant figure out how to delete them !! anyway ive gone back to the richtextbox way of displaying results and also added a column SwitchName.

i cant seem to format the text in the richtextbox called "logbox" based on result of ping ive tried adding the following code:

Code:

---

If Result.Status = Net.NetworkInformation.IPStatus.Success Then
            Switch.Result = True
            logbox.SelectionColor = Color.Green
        Else
            Switch.Result = False
            logbox.SelectionColor = Color.Red
  End If

---

but i keep getting cross thread issues , im new to mulit-threading so was wondering if anyone could help me out ?


im also having the same problem tryin to add a progressbar "progressbar1" , tried adding the following code but its not working:

Code:

---

        ProgressBar1.Minimum = 0                  'set minimum value                 
        ProgressBar1.Maximum = PingList.Count    'set maximum value

        ' Set up the progress bar's properties
        ProgressBar1.Value = ??

---

heres all the code:

Code:

---

Imports System.Data.OleDb

Public Class Form1

    ''' <summary>
    ''' Represents a network switch (or any device with an IP) that is in the database
    ''' </summary>
    Private Class NetworkSwitch
        Private _IPAddress As String
        Private _ID As Integer
        Private _SwitchName As String
        Private _Result As Boolean

        Public Property IPAddress() As String
            Get
                Return _IPAddress
            End Get
            Set(ByVal value As String)
                _IPAddress = value
            End Set
        End Property
        Public Property SwitchName() As String
            Get
                Return _SwitchName
            End Get
            Set(ByVal value As String)
                _SwitchName = value
            End Set
        End Property

        Public Property ID() As Integer
            Get
                Return _ID
            End Get
            Set(ByVal value As Integer)
                _ID = value
            End Set
        End Property

        Public Property Result() As Boolean
            Get
                Return _Result
            End Get
            Set(ByVal value As Boolean)
                _Result = value
            End Set
        End Property

    End Class

    'Set up some variables that we will use from various functions/subs
    Private PingList As List(Of NetworkSwitch)

    Private Counter As Integer = 0
    Private ConnString As New OleDbConnectionStringBuilder("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\test\pingDB.mdb;User Id=admin;Password=;")
    'This is the Delegate that will be used to pass data between the threads safely
    Private Delegate Sub PingComplete(ByVal sw As NetworkSwitch)


    Private Sub Pingbtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Pingbtn.Click
        Counter = 0 'reset the counter in case this is not the first time the ping button has been clicked
        Pingbtn.Enabled = False  'Disable the ping button so it cannot be pressed again yet
        btnExit.Enabled = False

        Dim bgthread As New Threading.Thread(AddressOf BG_CollectData)  'Create a new background thread
        bgthread.IsBackground = True  'Make the thread end if the program is closed
        bgthread.Start()  'Start the background thread

    End Sub

    ''' <summary>
    ''' This is the routine that is executed when bgthread.Start() is called in the event handler above
    ''' It collects information from the Access database and stores it in a list, then kicks off another
    ''' background thread (from the ThreadPool) that sends the ping
    ''' </summary>
    Private Sub BG_CollectData()
        'Create our connection that will be used to connect to the Access database
        Dim AccessConnection As New OleDbConnection(ConnString.ConnectionString)

        'Create the command that will be used to select all of the data in the IP and ID columns
        Dim SelectCommand As New OleDbCommand("SELECT * FROM PingTable", AccessConnection)

        'Create a new instance of a list of our NetworkSwitch class
        PingList = New List(Of NetworkSwitch)


        'Open the connection to the database
        AccessConnection.Open()

        'Use a DataReader to access the data that the SELECT command returns
        Dim Reader As OleDbDataReader = SelectCommand.ExecuteReader
        'Start to loop through the results
        'This loop will be restarted for each row in the database
        Do While Reader.Read
            'Create a new instance of our NetworkSwitch class and populate the ID and IP properties
            'with data from the current row in the database that we are looping through
            Dim CurrentSwitch As New NetworkSwitch
            With CurrentSwitch
                .ID = Reader("ID")
                .SwitchName = Reader("SwitchName")
                .IPAddress = Reader("IPAddress")
            End With
            'Add the new instance of the NetworkSwitch to our list
            PingList.Add(CurrentSwitch)
        Loop 'Start the loop again for the next record in the database

        'Close the connection because we have now processed all rows in the database
        AccessConnection.Close()

        'Give the threadpool a limit so that no more than 30 threads are running at the same time
        Threading.ThreadPool.SetMaxThreads(30, 400)

        'Loop through our list of NetworkSwitch instances and start (well, queue up) a new background
        'thread for each item in the list and passes it the current item in the loop (which is a NetworkSwitch object)
        For Each switchobject As NetworkSwitch In PingList
            Threading.ThreadPool.QueueUserWorkItem(New Threading.WaitCallback(AddressOf DoPing), switchobject)
        Next





    End Sub

    ''' <summary>
    ''' Performs the ping and updates the Result property of the NetworkSwitch object that was passed to this
    ''' </summary>
    Private Sub DoPing(ByVal Switch As NetworkSwitch)
        Dim Result As Net.NetworkInformation.PingReply
        Dim SendPing As New Net.NetworkInformation.Ping
        Result = SendPing.Send(Switch.IPAddress)
        If Result.Status = Net.NetworkInformation.IPStatus.Success Then
            Switch.Result = True




            ' <<<<<<----change Font Color to green/red ??
        Else
            Switch.Result = False


        End If


        UpdateDatabase(Switch)
        Counter += 1
        Me.Invoke(New PingComplete(AddressOf UI_PingComplete), Switch)

    End Sub

    ''' <summary>
    ''' This is executed each time a ping completes and the database has been updated.
    ''' It is executed on the UI thread because we used Me.Invoke to call it so it can access
    ''' controls on the UI thread without a problem
    ''' </summary>
    Private Sub UI_PingComplete(ByVal sw As NetworkSwitch)
        logbox.AppendText(sw.SwitchName & " - " & sw.IPAddress & " - ping complete - " & sw.Result & vbNewLine) 'update our log textbox

        If Counter = PingList.Count Then
            logbox.AppendText("Finished all tests" & vbNewLine)
            Pingbtn.Enabled = True 're-enable the ping button
            btnExit.Enabled = True
            PingList = Nothing 'clean up
        End If
    End Sub

    ''' <summary>
    ''' Updates the relevant row in the database for the switch that is passed to this method
    ''' </summary>
    Private Sub UpdateDatabase(ByVal sw As NetworkSwitch)

        Dim AccessConnection As New OleDbConnection(ConnString.ConnectionString)
        Dim UpdateCommand As New OleDbCommand("UPDATE PingTable SET Result=@Result, LastTested=@CurrentTime WHERE ID=@ID", AccessConnection)
        With UpdateCommand.Parameters
            .Add("@Result", OleDbType.Boolean).Value = sw.Result
            .Add("@CurrentTime", OleDbType.Char).Value = Now.ToString
            .Add("@ID", OleDbType.Integer).Value = sw.ID
            ' .Add("SwitchName", OleDbType.Char).Value = sw.SwitchName

        End With
        AccessConnection.Open()

        UpdateCommand.ExecuteNonQuery()  'Execute the command that updates the database

        AccessConnection.Close()


    End Sub

    Private Sub btnExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click
        End
    End Sub

 
End Class

---

OK I've attached an example project that uses a datagridview and I have attached the database. It is by no means perfect and you should add plenty of error handling etc as I have merely added enough to make it functional.
The way I have done it now is quite different in that you click the Reload button and it loads each row from the Access database into the DGV, then when you do the pings it actually just reads the data from the DGV and updates the DGV (but still updates the Access database as well with the results). Its probably not the best way to do it, especially as you would have to make sure you do the Reload after any changes are made to the database, but it works and at least gives you something to go on.

This is what it looks like:

http://i135.photobucket.com/albums/q...ngWinforms.jpg

I've also attached a WPF version for anyone who is interested, which uses data binding (because I find it much easier to do databinding in WPF) so doesnt require quite as much code - of course it also has the advantage of being a lot more visually flexible. For example, you can click the Change View button to switch from this view:

http://i135.photobucket.com/albums/q...t128/Ping1.jpg

to this view:

http://i135.photobucket.com/albums/q...t128/Ping2.jpg

Obviously just a very basic example but you get the idea :)

Note that I have changed quite a few things in the code compared to that example project I gave you before. For example the LastTested column is now a Date column not a text column and as a result when the app is loading the data into the DGV it will display something like 01/01/0001 00:00:00 as the last tested date if there is no value in that column. You could stick some extra If statements in there to 'convert' it from that date into a string that just says "Never" or something and then do the opposite when reading the data from the DGV but I havent bothered as its just an example.

Read the comments in the code and feel free to ask any questions - also just to clarify, this is not meant to be a working program that you can just start using (although it does work), its more to help you see how you can do things. As I said though, there is probably a better way of doing things, its just my own example :)

thanks chris , one more thing im trying to open this program using another vb program as in have a command button in another vb app open up the pinging application but , from what i gather shell is the way to go

ive tried the following:

Code:

---

Private Sub Ping_Click()
Shell "C:\Documents and Settings\mhorgan\Desktop\example ping\ExamplePingProgram\ExamplePingProgram"
End Sub

---

but no luck, is it maybe the space in between the documents_and_settings in the directory ? or am i way off here ? or aproblem with a missing file extension ?

No Shell is not the way to go really, Process.Start is the way to go.

vb Code:

Process.Start("C:\Folder Path Here\ExamplePingProgram.exe")

just one final thing ,im tryin to add a progress bar and was wondering what to set max and value to , and also where to place this code

ProgressBar1.Minimum = 0
ProgressBar1.Maximum = ?
ProgressBar1.Value = ?

heres code:

Code:

---

Imports System.Data.OleDb

Public Class Form1

    ''' <summary>
    ''' Represents a network switch (or any device with an IP) that is in the database
    ''' </summary>
    Private Class NetworkSwitch
        Private _IPAddress As String
        Private _SwitchID As Integer
        Private _SwitchName As String
        Private _Result As Boolean

        Public Property IPAddress() As String
            Get
                Return _IPAddress
            End Get
            Set(ByVal value As String)
                _IPAddress = value
            End Set
        End Property
        Public Property SwitchName() As String
            Get
                Return _SwitchName
            End Get
            Set(ByVal value As String)
                _SwitchName = value
            End Set
        End Property

        Public Property SwitchID() As Integer
            Get
                Return _SwitchID
            End Get
            Set(ByVal value As Integer)
                _SwitchID = value
            End Set
        End Property

        Public Property Result() As Boolean
            Get
                Return _Result
            End Get
            Set(ByVal value As Boolean)
                _Result = value
            End Set
        End Property

    End Class

    'Set up some variables that we will use from various functions/subs
    Private PingList As List(Of NetworkSwitch)

    Private Counter As Integer = 0
    Private ConnString As New OleDbConnectionStringBuilder("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Documents and Settings\mhorgan\Desktop\Network Map.mdb;User Id=admin;Password=;")
    'This is the Delegate that will be used to pass data between the threads safely
    Private Delegate Sub PingComplete(ByVal sw As NetworkSwitch)


    Private Sub Pingbtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Pingbtn.Click
        Label1.Visible = True
        Counter = 0 'reset the counter in case this is not the first time the ping button has been clicked
        Pingbtn.Enabled = False  'Disable the ping button so it cannot be pressed again yet
        btnExit.Enabled = False
        btnMap.Enabled = False
        btnDB.Enabled = False

        Dim bgthread As New Threading.Thread(AddressOf BG_CollectData)  'Create a new background thread
        bgthread.IsBackground = True  'Make the thread end if the program is closed
        bgthread.Start()  'Start the background thread

    End Sub

    ''' <summary>
    ''' This is the routine that is executed when bgthread.Start() is called in the event handler above
    ''' It collects information from the Access database and stores it in a list, then kicks off another
    ''' background thread (from the ThreadPool) that sends the ping
    ''' </summary>
    Private Sub BG_CollectData()
        'Create our connection that will be used to connect to the Access database
        Dim AccessConnection As New OleDbConnection(ConnString.ConnectionString)

        'Create the command that will be used to select all of the data in the IP and ID columns
        Dim SelectCommand As New OleDbCommand("SELECT * FROM tblSwitch", AccessConnection)

        'Create a new instance of a list of our NetworkSwitch class
        PingList = New List(Of NetworkSwitch)


        'Open the connection to the database
        AccessConnection.Open()

        'Use a DataReader to access the data that the SELECT command returns
        Dim Reader As OleDbDataReader = SelectCommand.ExecuteReader
        'Start to loop through the results
        'This loop will be restarted for each row in the database
        Do While Reader.Read
            'Create a new instance of our NetworkSwitch class and populate the ID and IP properties
            'with data from the current row in the database that we are looping through
            Dim CurrentSwitch As New NetworkSwitch
            With CurrentSwitch
                .SwitchID = Reader("SwitchID")
                .SwitchName = Reader("SwitchName")
                .IPAddress = Reader("IPAddress")
            End With
            'Add the new instance of the NetworkSwitch to our list
            PingList.Add(CurrentSwitch)
        Loop 'Start the loop again for the next record in the database

        'Close the connection because we have now processed all rows in the database
        AccessConnection.Close()

        'Give the threadpool a limit so that no more than 30 threads are running at the same time
        Threading.ThreadPool.SetMaxThreads(30, 400)

        'Loop through our list of NetworkSwitch instances and start (well, queue up) a new background
        'thread for each item in the list and passes it the current item in the loop (which is a NetworkSwitch object)
        For Each switchobject As NetworkSwitch In PingList
            Threading.ThreadPool.QueueUserWorkItem(New Threading.WaitCallback(AddressOf DoPing), switchobject)
        Next


    End Sub

    ''' <summary>
    ''' Performs the ping and updates the Result property of the NetworkSwitch object that was passed to this
    ''' </summary>
    Private Sub DoPing(ByVal Switch As NetworkSwitch)
        Dim Result As Net.NetworkInformation.PingReply
        Dim SendPing As New Net.NetworkInformation.Ping
        Result = SendPing.Send(Switch.IPAddress)
        If Result.Status = Net.NetworkInformation.IPStatus.Success Then
            Switch.Result = True


        Else
            Switch.Result = False


        End If


        UpdateDatabase(Switch)
        Counter += 1
        Me.Invoke(New PingComplete(AddressOf UI_PingComplete), Switch)

    End Sub

    ''' <summary>
    ''' This is executed each time a ping completes and the database has been updated.
    ''' It is executed on the UI thread because we used Me.Invoke to call it so it can access
    ''' controls on the UI thread without a problem
    ''' </summary>
    Private Sub UI_PingComplete(ByVal sw As NetworkSwitch)
        If sw.Result = True Then
            logbox.SelectionColor = Color.DarkBlue
        ElseIf sw.Result = False Then

            logbox.SelectionColor = Color.Red

        End If

        logbox.AppendText(sw.SwitchID & "--" & sw.SwitchName & " -- " & sw.IPAddress & " -- ping complete -- " & sw.Result & vbNewLine) 'update our log textbox

        If Counter = PingList.Count Then
            logbox.AppendText(vbNewLine & vbNewLine & "Finished all tests" & vbNewLine)
            Pingbtn.Enabled = True 're-enable the ping button
            btnExit.Enabled = True
            btnMap.Enabled = True
            btnDB.Enabled = True
            PingList = Nothing 'clean up
        End If
    End Sub

    ''' <summary>
    ''' Updates the relevant row in the database for the switch that is passed to this method
    ''' </summary>
    Private Sub UpdateDatabase(ByVal sw As NetworkSwitch)

        Dim AccessConnection As New OleDbConnection(ConnString.ConnectionString)
        Dim UpdateCommand As New OleDbCommand("UPDATE tblSwitch SET Result=@Result, LastTested=@CurrentTime WHERE SwitchID=@SwitchID", AccessConnection)
        With UpdateCommand.Parameters
            .Add("@Result", OleDbType.Boolean).Value = sw.Result
            .Add("@CurrentTime", OleDbType.Char).Value = Now.ToString
            .Add("@SwitchID", OleDbType.Integer).Value = sw.SwitchID


        End With
        AccessConnection.Open()

        UpdateCommand.ExecuteNonQuery()  'Execute the command that updates the database

        AccessConnection.Close()


    End Sub

    Private Sub btnExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click
        End ' closes application
    End Sub

    Private Sub btnMap_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnMap.Click
        Process.Start("C:\Documents and Settings\mhorgan\Desktop\NewEffort.vsd")  ' opens Network Map
    End Sub

    Private Sub btnDB_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDB.Click
        Process.Start("C:\Documents and Settings\mhorgan\Desktop\Network Map.mdb") 'opens AccessDB
    End Sub
End Class

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