How to correctly use a progress bar while a long task is running visual studio 2008

The 'correct' way to accomplish this would be to run the long-running task on a background thread and use the foreground thread to update the progress bar. The simplest way to do that would be to use code similar to the following (it's in C# as it's the only example I had handy, should be very easy to translate).

            // spawn off a new thread to do the actual work
            Thread worker = new Thread(new ThreadStart(<methodToRunInBackground>));
            worker.Start();
 
            // update the progress bar while waiting for the
            //     other thread to get done with itself
            while (worker.IsAlive)
            {
                Thread.Sleep(1000);
                UpdateProgressBar();
            };
            
            progressBar1.Value = progressBar1.Minimum;

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Yep, I tried that, but I get this error:  Cross-Thread operation not valid: Control 'flptube' accessed from a thread other then the thread it was created on.   The build_query, which is the main procedure, dynamically builds panels and adds them to that control flptube.  

I found something that is suppose to make the threading function more like .net 1.1  
Me.CheckForIllegalCrossThreadCalls = False.  This allows the cross threading, but then I get another error.  So I am kinda at a loss.

With VB.Net 2008 you set the ProgressBar.Style to Marquee and it will continuosly move to show an operation is in progress:

    ss_progress_bar.Style = ProgressBarStyle.Marquee

Play with this simple example:

Public Class Form1
 
    Private WithEvents bgw As New System.ComponentModel.BackgroundWorker
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        ProgressBar1.Style = ProgressBarStyle.Marquee
        bgw.WorkerReportsProgress = True
        bgw.RunWorkerAsync()
    End Sub
 
    Private Sub bgw_DoWork(ByVal sender As Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles bgw.DoWork
        ' this is running in a DIFFERENT thread
        For i As Integer = 1 To 5
            Dim btn As New Button
            btn.Location = New Point(10, i * 25)
            btn.Text = "#" & i
            AddHandler btn.Click, AddressOf btn_Click
            bgw.ReportProgress(0, btn)
            System.Threading.Thread.Sleep(2000) ' simulated "work" so you can see the progressbar "marquee" mode in action
        Next
    End Sub
 
    Private Sub bgw_ProgressChanged(ByVal sender As Object, ByVal e As System.ComponentModel.ProgressChangedEventArgs) Handles bgw.ProgressChanged
        ' this is running in the main UI Thread
        Me.Controls.Add(e.UserState)
    End Sub
 
    Private Sub bgw_RunWorkerCompleted(ByVal sender As Object, ByVal e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles bgw.RunWorkerCompleted
        ' this is running in the main UI Thread
        ProgressBar1.Style = ProgressBarStyle.Blocks
        ProgressBar1.Visible = False
    End Sub
 
    Private Sub btn_Click(ByVal sender As Object, ByVal e As System.EventArgs)
        MessageBox.Show(sender.text)
    End Sub
 
End Class

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That CheckForIllegalCrossThreadCalls property in .NET 1.1 was a bit of a cheat. In .NET 2.0 and up you need to check to see if an invoke is required and if so marshall the call back to the UI thread. I've attached some code that does this.

In this case the method that I'm calling (BuildDeployList) doesn't take any argument so I can use the Action delegate that is built into the framework. If your method (the one that adds the panel to the UI) takes argument you'll need to declare a delegate for it and use it in place of Action, or use the generic Action delegate. For example:

        private delegate void SetToolStripItemEnabledStateDelegate( ToolStripItem item, bool state );

or

       Action<int, string>

private void BuildDeployList()
{
    if( this.InvokeRequired )
    {
        Action action = BuildDeployList;
        this.Invoke( action );
    }
    else
    {
        AddTestsToListBox( lstAvailableTests, Directory.GetFiles( DeployFolder, "*.zip" ) );
        SetControlStates();
    }
}

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Ok, I am a little confused on how to get this to work

Here is the thread that executes the query: build_query, and updates the progress bar.  Within the the build_query I call another procedure that interacts with the control and gets passed 8 paramaters.  I am unsure how to make this work.
I took out a lot of code that involves query the db and adding some stuff that doesnt matter with my question.  If you look at the build_panel procedure the last line where I try to add the controls is where the error occurs.  I am not sure how to declare the delegate.

Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
      Dim worker As New System.Threading.Thread(AddressOf build_query)
        worker.Start()
        While worker.IsAlive
            Threading.Thread.Sleep(900)
            If Me.ss_progress_bar.Value < ss_progress_bar.Maximum Then
                ss_progress_bar.Increment(10)
            Else
                ss_progress_bar.Value = 0
            End If
        End While
        ss_progress_bar.Value = ss_progress_bar.Minimum
    End Sub
 
  Sub build_query()
        Dim data_adap As OracleDataAdapter
        Dim ds As New DataSet
        Dim dr As DataRow
        Dim job, item, description, qty, temp_qty As String
        Dim col_name As String
        Dim sched_start_date As Date
        ssql = "select columns here from table name"
        data_adap = New OracleDataAdapter(ssql, ora_conn)
        Try
            data_adap.Fill(ds, "Table1")
            For Each dr In ds.Tables(0).Rows
                job = dr.Item(0).ToString
                item = dr.Item(1).ToString
                description = dr.Item(2).ToString
                sched_start_date = dr.Item(3)
                qty = dr.Item(4).ToString
                For i As Integer = 5 To ds.Tables(0).Columns.Count - 1
                    Dim l As New Label
                    Dim v As Array
 col_name = ds.Tables(0).Columns.Item(i).ColumnName                     
v = Me.Controls.Find("flp" & col_name.ToLower, True)
                    If v.Length >= 1 Then
                        temp_qty = dr.Item(i + 1).ToString
build_panel(job, item, description, sched_start_date, qty, temp_qty, v(0), dr.Item(i).ToString)
                        i += 1
                    End If
                Next
                row_count += 1
            Next
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    End Sub
 
 Sub build_panel(ByVal job_number As String, ByVal item_number As String, ByVal description As String, ByVal shed_date As Date, ByVal total_qty As String, ByVal run_qty As String, ByVal temp_panel As FlowLayoutPanel, ByVal part_number As String)
        Dim ptemp As New Panel
        Dim l_desc As New Label
        Dim l_part_num As New Label
        Dim l_qty As New Label
        Dim l_date As New Label
           With l_part_num
            .Text = part_number
            .ForeColor = Color.Black
            .AutoSize = True
            .Font = New Font(Font.Name, 8)
            .Location = New Point(ptemp.Location.X + 22, ptemp.Location.Y - 1)
        End With
        With l_desc
            .Text = description            
            .ForeColor = Color.Black
            .Font = New Font(Font.Name, 5.5, FontStyle.Regular)
            .AutoSize = True
            .Location = New Point(ptemp.Location.X + 1, ptemp.Location.Y + 13)
        End With
        With l_date
            .Text = shed_date.ToString("M/d")
            .ForeColor = Color.Black
            .AutoSize = True
            .Font = New Font(Font.Name, 7)
            .Location = New Point(ptemp.Location.X - 2, ptemp.Location.Y - 1)
        End With
         With l_qty
            .Text = run_qty & "/" & total_qty
            .ForeColor = Color.Black()
            .BackColor = Color.White
            .AutoSize = True
            .RightToLeft = Windows.Forms.RightToLeft.Inherit
            .Location = New Point(ptemp.Location.X + 27, ptemp.Location.Y + 21)
            .Font = New Font(Font.Name, 7)
            .TextAlign = ContentAlignment.MiddleCenter
        End With
          ptemp.Controls.Add(l_part_num)
            ptemp.Controls.Add(l_date)
            ptemp.Controls.Add(l_desc)
            ptemp.Controls.Add(l_qty)
        temp_panel.Controls.Add(ptemp)
    End Sub

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Because it takes eight parameters you won't be able to use Action, it maxes out at four parameters.

I don't use VB.NET, I'm developing in C#, so I don't know the syntax for declaring a delegate off the top of my head in VB.NET.

Accoding to this page (http://www.developerfusion.com/article/5251/delegates-in-vbnet) the declaration is the same as any other variable in VB.NET.

Private Delegate Sub MyDelSub()

The delegate is a variable that represents your method, so it must match the method in terms of arguments and return type. In your case:

Private Delegate Sub BuildPanelDelegate(ByVal job_number As String, ByVal item_number As String, ByVal description As String, ByVal shed_date As Date, ByVal total_qty As String, ByVal run_qty As String, ByVal temp_panel As FlowLayoutPanel, ByVal part_number As String)

Create an if/else statement with a condition checking the form for InvokeRequired. Put all the existing code in the else block. In the if block, declare an instance of the delegate and invoke it.

Some of the syntax may be wrong, as I mentioned I don't use VB.NET and I'm hand-coding this without benefit of Intellisense.

If Me.InvokeRequired Then
    ' Declare a variable to hold a pointer to the function
    Dim theDelegate As BuildPanelDelegate
    ' Assign the variable the address of the function to call
    theDelegate = new BuildPanelDelegate(AddressOf build_panel)
    ' Marshall the function call back to the UI thread
    theDelegate.Invoke( job_number, item_number, etc... the rest of the arguments)
Else
    ' all the existing code goes here
End If

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I set up the delegate and it loads the procedure fine, but I still get the same error when it tries to add controls to the panel.  Not sure what i am doing wrong.

Public Delegate Sub delegate_panel(ByVal job_number As String, ByVal item_number As String, ByVal description As String, ByVal shed_date As Date, ByVal total_qty As String, ByVal run_qty As String, ByVal temp_panel As FlowLayoutPanel, ByVal part_number As String)
 
 
        If Me.InvokeRequired Then
            Dim objdele As delegate_panel
            objdele = AddressOf delegate_panel_build
            objdele.Invoke(job_number, item_number, description, shed_date, total_qty, run_qty, temp_panel, part_number)
        Else
           'other work here
   end if
 
 Sub delegate_panel_build(ByVal job_number As String, ByVal item_number As String, ByVal description As String, ByVal shed_date As Date, ByVal total_qty As String, ByVal run_qty As String, ByVal temp_panel As FlowLayoutPanel, ByVal part_number As String)
        Dim ptemp As New Panel
        Dim l_desc As New Label
        Dim l_part_num As New Label
        Dim l_qty As New Label
        Dim l_date As New Label
        With l_part_num
            .Text = part_number
            .ForeColor = Color.Black
            .AutoSize = True
            .Font = New Font(Font.Name, 8)
            .Location = New Point(ptemp.Location.X + 22, ptemp.Location.Y - 1)
        End With
        With l_desc
            .Text = description
            .ForeColor = Color.Black
            .Font = New Font(Font.Name, 5.5, FontStyle.Regular)
            .AutoSize = True
            .Location = New Point(ptemp.Location.X + 1, ptemp.Location.Y + 13)
        End With
        With l_date
            .Text = shed_date.ToString("M/d")
            .ForeColor = Color.Black
            .AutoSize = True
            .Font = New Font(Font.Name, 7)
            .Location = New Point(ptemp.Location.X - 2, ptemp.Location.Y - 1)
        End With
        If run_qty = "" Then run_qty = 123
        With l_qty
            .Text = run_qty & "/" & total_qty
            .ForeColor = Color.Black()
            .BackColor = Color.White
            .AutoSize = True
            .RightToLeft = Windows.Forms.RightToLeft.Inherit
            .Location = New Point(ptemp.Location.X + 27, ptemp.Location.Y + 21)
            .Font = New Font(Font.Name, 7)
            .TextAlign = ContentAlignment.MiddleCenter
        End With
        If part_number <> "" Then
            ptemp.Controls.Add(l_part_num)
            ptemp.Controls.Add(l_date)
            ptemp.Controls.Add(l_desc)
            ptemp.Controls.Add(l_qty)
            ptemp.Tag = job_number & "~" & item_number & "~" & part_number
            ptemp.Width = temp_panel.Width - 5
            ptemp.Height = 34
            ptemp.BorderStyle = BorderStyle.None
            ptemp.BackColor = Color.Yellow
            AddHandler ptemp.Click, AddressOf Ptemp_Click
            AddHandler l_desc.Click, AddressOf Ptemp_Click
            AddHandler l_qty.Click, AddressOf Ptemp_Click
            AddHandler l_part_num.Click, AddressOf Ptemp_Click
            AddHandler l_date.Click, AddressOf Ptemp_Click
        Else
            ptemp.Tag = "0"
            ptemp.Width = temp_panel.Width
            ptemp.Height = 34
            ptemp.BorderStyle = BorderStyle.None
            ptemp.BackColor = Color.Transparent
        End If
        temp_panel.Controls.Add(ptemp)
    End Sub

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A delegate is a variable declaration, not a method declaration. It looks like you declared your delegate and then gave a method body to it. If what you pasted is your actual code, I'm a little surprised it even compiled, but as I've said before, I don't use VB.NET.

See below for how it should be set up.

Private Delegate Sub delegate_panel(ByVal job_number As String, ByVal item_number As String, ByVal description As String, ByVal shed_date As Date, ByVal total_qty As String, ByVal run_qty As String, ByVal temp_panel As FlowLayoutPanel, ByVal part_number As String)
 
Sub delegate_panel_build(ByVal job_number As String, ByVal item_number As String, ByVal description As String, ByVal shed_date As Date, ByVal total_qty As String, ByVal run_qty As String, ByVal temp_panel As FlowLayoutPanel, ByVal part_number As String)
    If Me.InvokeRequired Then
        Dim objdele As delegate_panel
        objdele = AddressOf delegate_panel_build
        objdele.Invoke(job_number, item_number, description, shed_date, total_qty, run_qty, temp_panel, part_number)
    Else
        Dim ptemp As New Panel
        Dim l_desc As New Label
        Dim l_part_num As New Label
        Dim l_qty As New Label
        Dim l_date As New Label
        With l_part_num
            .Text = part_number
            .ForeColor = Color.Black
            .AutoSize = True
            .Font = New Font(Font.Name, 8)
            .Location = New Point(ptemp.Location.X + 22, ptemp.Location.Y - 1)
        End With
        With l_desc
            .Text = description
            .ForeColor = Color.Black
            .Font = New Font(Font.Name, 5.5, FontStyle.Regular)
            .AutoSize = True
            .Location = New Point(ptemp.Location.X + 1, ptemp.Location.Y + 13)
        End With
        With l_date
            .Text = shed_date.ToString("M/d")
            .ForeColor = Color.Black
            .AutoSize = True
            .Font = New Font(Font.Name, 7)
            .Location = New Point(ptemp.Location.X - 2, ptemp.Location.Y - 1)
        End With
        If run_qty = "" Then run_qty = 123
        With l_qty
            .Text = run_qty & "/" & total_qty
            .ForeColor = Color.Black()
            .BackColor = Color.White
            .AutoSize = True
            .RightToLeft = Windows.Forms.RightToLeft.Inherit
            .Location = New Point(ptemp.Location.X + 27, ptemp.Location.Y + 21)
            .Font = New Font(Font.Name, 7)
            .TextAlign = ContentAlignment.MiddleCenter
        End With
        If part_number <> "" Then
            ptemp.Controls.Add(l_part_num)
            ptemp.Controls.Add(l_date)
            ptemp.Controls.Add(l_desc)
            ptemp.Controls.Add(l_qty)
            ptemp.Tag = job_number & "~" & item_number & "~" & part_number
            ptemp.Width = temp_panel.Width - 5
            ptemp.Height = 34
            ptemp.BorderStyle = BorderStyle.None
            ptemp.BackColor = Color.Yellow
            AddHandler ptemp.Click, AddressOf Ptemp_Click
            AddHandler l_desc.Click, AddressOf Ptemp_Click
            AddHandler l_qty.Click, AddressOf Ptemp_Click
            AddHandler l_part_num.Click, AddressOf Ptemp_Click
            AddHandler l_date.Click, AddressOf Ptemp_Click
        Else
            ptemp.Tag = "0"
            ptemp.Width = temp_panel.Width
            ptemp.Height = 34
            ptemp.BorderStyle = BorderStyle.None
            ptemp.BackColor = Color.Transparent
        End If
        temp_panel.Controls.Add(ptemp)
    End If
End Sub

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Ok, I changed it to what you had, now it gets into a never ending loop when it checks the condition

  If Me.InvokeRequired Then
             Dim objdele As delegate_panel
            objdele = AddressOf delegate_panel_build
            objdele.Invoke(job_number, item_number, description, shed_date, total_qty, run_qty, temp_panel, part_number)

else

end if


Something is not right I dont think i am calling the procedure right.  When the form loads it create the worker thread which calls the build_query procedure.  Within the build_query procedure, I loop the contents of a dataset, then call the delegate_panel_build procedure which contains the delegate call and invoke.  Is this right so far, if it is something is wrong.

  Private Delegate Sub delegate_panel(ByVal job_number As String, ByVal item_number As String, ByVal description As String, ByVal shed_date As Date, ByVal total_qty As String, ByVal run_qty As String, ByVal temp_panel As FlowLayoutPanel, ByVal part_number As String)
 
 Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim worker As New System.Threading.Thread(AddressOf build_query)
        worker.Start()
        While worker.IsAlive
            Threading.Thread.Sleep(700)
            If Me.ss_progress_bar.Value < ss_progress_bar.Maximum Then
                ss_progress_bar.Increment(10)
            Else
                ss_progress_bar.Value = 0
            End If
        End While
        ss_progress_bar.Value = ss_progress_bar.Minimum
    End Sub
 
   Sub build_query()
         Dim data_adap As OracleDataAdapter
        Dim ds As New DataSet
        Dim row_count As Integer = 0 'keeps track of the rows
        Dim dr As DataRow
        Dim job, item, description, qty, temp_qty As String
        Dim col_name As String
        Dim sched_start_date As Date
        ssql = "select here"
        data_adap = New OracleDataAdapter(ssql, ora_conn)
        Try
            data_adap.Fill(ds, "Table1")
            For Each dr In ds.Tables(0).Rows
                job = dr.Item(0).ToString
                item = dr.Item(1).ToString
                description = dr.Item(2).ToString
                sched_start_date = dr.Item(3)
                qty = dr.Item(4).ToString
                For i As Integer = 5 To ds.Tables(0).Columns.Count - 1
                    'This loop is for looping all the cylinder components
                    Dim l As New Label
                    Dim v As Array
                    col_name = ds.Tables(0).Columns.Item(i).ColumnName 'Get the column name so they can be sorted by component
                    v = Me.Controls.Find("flp" & col_name.ToLower, True)
                    If v.Length >= 1 Then
                        temp_qty = dr.Item(i + 1).ToString
                        delegate_panel_buildjob, item, description, sched_start_date, qty, temp_qty, v(0), dr.Item(i).ToString)
                        i += 1
                    End If
                Next
                row_count += 1
            Next
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        Finally
 
        End Try
    End Sub
 
Sub delegate_panel_build(ByVal job_number As String, ByVal item_number As String, ByVal description As String, ByVal shed_date As Date, ByVal total_qty As String, ByVal run_qty As String, ByVal temp_panel As FlowLayoutPanel, ByVal part_number As String)
        Dim ptemp As New Panel
        Dim l_desc As New Label
        Dim l_part_num As New Label
        Dim l_qty As New Label
        Dim l_date As New Label
        If Me.InvokeRequired Then
             Dim objdele As delegate_panel
            objdele = AddressOf delegate_panel_build
            objdele.Invoke(job_number, item_number, description, shed_date, total_qty, run_qty, temp_panel, part_number)
        Else
            With l_part_num
                .Text = part_number
                .ForeColor = Color.Black
                .AutoSize = True
                .Font = New Font(Font.Name, 8)
                .Location = New Point(ptemp.Location.X + 22, ptemp.Location.Y - 1)
            End With
            With l_desc
                .Text = description.Replace("CYL ASSY", "")
                .ForeColor = Color.Black
                .Font = New Font(Font.Name, 5.5, FontStyle.Regular)
                .AutoSize = True
                .Location = New Point(ptemp.Location.X + 1, ptemp.Location.Y + 13)
            End With
            With l_date
                .Text = shed_date.ToString("M/d")
                .ForeColor = Color.Black
                .AutoSize = True
                .Font = New Font(Font.Name, 7)
                .Location = New Point(ptemp.Location.X - 2, ptemp.Location.Y - 1)
            End With
            If run_qty = "" Then run_qty = 123
            With l_qty
                .Text = run_qty & "/" & total_qty
                .ForeColor = Color.Black()
                .BackColor = Color.White
                .AutoSize = True
                .RightToLeft = Windows.Forms.RightToLeft.Inherit
                .Location = New Point(ptemp.Location.X + 27, ptemp.Location.Y + 21)
                .Font = New Font(Font.Name, 7)
                .TextAlign = ContentAlignment.MiddleCenter
            End With
            If part_number <> "" Then
                ptemp.Controls.Add(l_part_num)
                ptemp.Controls.Add(l_date)
                ptemp.Controls.Add(l_desc)
                ptemp.Controls.Add(l_qty)
                ptemp.Tag = job_number & "~" & item_number & "~" & part_number
                ptemp.Width = temp_panel.Width - 5
                ptemp.Height = 34
                ptemp.BorderStyle = BorderStyle.None
                ptemp.BackColor = Color.Yellow
                AddHandler ptemp.Click, AddressOf Ptemp_Click
                AddHandler l_desc.Click, AddressOf Ptemp_Click
                AddHandler l_qty.Click, AddressOf Ptemp_Click
                AddHandler l_part_num.Click, AddressOf Ptemp_Click
                AddHandler l_date.Click, AddressOf Ptemp_Click
            Else
                ptemp.Tag = "0"
                ptemp.Width = temp_panel.Width
                ptemp.Height = 34
                ptemp.BorderStyle = BorderStyle.None
                ptemp.BackColor = Color.Transparent
            End If
            temp_panel.Controls.Add(ptemp)
        End If
    End Sub

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Change:

        If Me.InvokeRequired Then
            Dim objdele As delegate_panel
            objdele = AddressOf delegate_panel_build
            objdele.Invoke(job_number, item_number, description, shed_date, total_qty, run_qty, temp_panel, part_number)

To:

        If Me.InvokeRequired Then
            Me.Invoke(New delegate_panel(AddressOf delegate_panel_build),  New Object() {job_number, item_number, description, shed_date, total_qty, run_qty, temp_panel, part_number})

Tried that as well and it just keeps thinking nothing happens.

When the program tries to execute this line of code, the thread just locks up and nothing happens, any ideas?  Am I still not invoking the the delegate property.

 Me.Invoke(New delegate_panel(AddressOf delegate_panel_build), New Object() {job_number, item_number, description, shed_date, total_qty, run_qty, temp_panel, part_number})

I haven't studied your code...I'll take a CLOSER look later...

Nice,
It looks like it worked.  Could you explain these 2 procedures I am not familiar with the Action delegate, is that new?
I am not familiar
 Sub start_progress()
        If Me.InvokeRequired Then
            Dim dele As Action
            dele = AddressOf start_progress
            Me.Invoke(dele)
        Else
            ss_progress_bar.Style = ProgressBarStyle.Marquee
        End If
    End Sub

    Sub stop_progress()
        If Me.InvokeRequired Then
            Dim dele As Action
            dele = AddressOf start_progress
            Me.Invoke(dele)
        Else
            ss_progress_bar.Style = ProgressBarStyle.Blocks
        End If
    End Sub

They just use Maquee mode, which keeps the progress bar moving all the time. When the long-running process starts it puts the bar into Marquee mode, when it's done it puts it back into regular mode.

As far as the Action delegate goes,

http://msdn.microsoft.com/en-us/library/system.action.aspx

"Encapsulates a method that takes no parameters and does not return a value."

The stop_process is not working, the progress bar never leaves marquee mode.

I got the stop_process working, but now I need to execute the worker thread every halfhour.  

Ok, i thought I had everything working, I created a timer thread that runs every 10 seconds.  It was working fine but I watched it for a while, then all of a sudden i got this error:  Error Creating Window Handle,  what is this?

I increased the points because this was a lot more work then I initionally thought.

   Dim duetime As New TimeSpan(0, 0, 1) 'how long to wait before starting timer
    Dim ticktime As New TimeSpan(0, 0, 0, 0, 10000) 'Number of seconds in milleseconds between each tick
  
 
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim frm_login As New Login
        frm_login.ShowDialog()
        If login_status Then
                  thtimer = New System.Threading.Timer(New System.Threading.TimerCallback(AddressOf build_query), Nothing, duetime, ticktime)
         End If
    End Sub

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Figured out that it loops through 9 times, then it crashes.  Do i need to do some cleanup?

Getting closer here, I found out that i basically need to do some garbage cleanup before creating all the new panels.  I created a loop that should go through and dispose of all existing controls before creating new ones.  I can't quite get it to work and I am not sure where I should put the procedure call

 Sub clear_controls(ByVal ctrl As Control) 
        Dim frmctrl As Control
        Dim flow_p_controls As Control
        For Each frmctrl In ctrl.Controls
            If TypeOf frmctrl Is FlowLayoutPanel Then
                If frmctrl.HasChildren Then
                    For Each flow_p_controls In frmctrl.Controls
                        flow_p_controls.Dispose()
                    Next
                End If
            End If
            If frmctrl.HasChildren Then
                clear_controls(frmctrl)
            End If
        Next
    End Sub

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I found this very helpful, thx.