Re: there probably is a mistake somewhere - Visual Basic Discussion Boards

I thought I already give all the information needed.

The Run_Tool() will be called when user click "Run" item in the menu.

Inside Run_Tool(), a process will be created to run an exe file, at the same time, a form with progress bar will be created and displayed (let's forget about the progress bar value at this time), I also add an event Exited for the procee, when the event is called, close the form with progress bar, that's it.

Now the problem is that the Exited event is never called, so form progBarFrm is never closed.

 Dim progBarFrm as FormProgressBar

 Private Sub OnProcesited(ByVal sender As Object, ByVal e As System.EventArgs)
    Dim p As System.Diagnostics.Process
    p = sender

    progBarFrm.Close()
    progBarFrm.Dispose()


End Sub


Private Sub Run_Tool()

    Dim sAppPath As String = ".\XXXX.exe"
    Dim fileName As String = "DDDDDDDDDDDDDDDD.txt"
    Dim p As New System.Diagnostics.Process()



    p.StartInfo.FileName = Application.StartupPath & "\" & sAppPath
    p.StartInfo.Arguments = fileName

    'Do not use the system shell to start the program this is so we can hide the command dos window
    p.StartInfo.UseShellExecute = False
    p.StartInfo.WorkingDirectory = strOutputFilePath
    ' Show no dos window if false
    p.StartInfo.CreateNoWindow = True
    p.StartInfo.RedirectStandardOutput = True
    p.EnableRaisingEvents = True
    AddHandler p.Exited, AddressOf OnProcesited


    progBarFrm = New FormProgressBar

    Try
        p.Start()

        progBarFrm.Show()
        progBarFrm.Refresh()

    Catch ex As Exception
        ShowValidationMessage("Unexception error is caught, please close and try again.", "Error")
        'p.Kill()
        Return
    End Try




    ''Shell(sAppPath, vbNormalFocus) 'other options for starting with

End Sub

modified on Tuesday, May 24, 2011 2:21 PM

That clearly is not the entire story. Are you waiting for the process to exit somewhere? what is in the "Run clicked" handler? Is your app responsive (can you move its main window, will it repaint) while the process runs?
one handler can not execute while another one is still running!

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.

That's the whole codes when "Run" is clicked.

Yes, I need to waiting for the process to exit, I need to get the return string and display them in the form. That's why I use
p.WaitForExit(5400000). But use p.WaitForExit(5400000) will hang progressbar form, if don;t use p.WaitForExit(5400000), when should I close the progressbar form?

Private Sub OnProcesited(ByVal sender As Object, ByVal e As System.EventArgs)
   Dim p As System.Diagnostics.Process
   p = sender

   Dim rtnStr As String = String.Empty
   rtnStr = p.StandardOutput.ReadToEnd()

   If rtnStr.Contains(" FAST terminated normally.") = True Then
       rtnStr = rtnStr & vbCrLf & "Please click Postprocess -> View Output File in menu to view the file."
       updateViewMenu()
   End If
   '''progBarFrm.Close()
   '''progBarFrm.Dispose()
   
   Dim frm As New FormShowFASTResult
   frm.txtFASTResult.Text = rtnStr
   frm.Button1.Select()
   frm.ShowDialog()
 End Sub

You still have absolutely nothing updating the progress bar. You called Show on the form to show the form with the progress bar on it, but you've got nothing at all that updates the progress bar, so it's not going to do anything.

Without seeing the code behind the progressbar form, this is about all we can say.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Progressbar value should be updated using timer inside the form, after call SHOW of the form, the timer will be started, sure you cannot see these codes from inside the function which create the form.

I found only if I clearly call p.Kill(), the Exited event will be triggered, but when I should call the .Kill() for a process?

if I use p.WaitForExit(5400000), the program will be hanged to wait for process to exit, the progressbar form will be hanged.

The process will drop by itself. You shouldn't have to call Kill on it at all. Once the process you launched quits on its own, the Exited event will be raised.

5400000?? Really? 90 minutes??

You do realize WaitForExit is a blocking call, right? No other code will execute so long as WaitForExit is waiting. Remove this line and just let it run. When the target app is finished, your event handler will get called.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Sorry calculation error, I already comment out that line. Now I modify the source codes, also remove the event.

When "Run" menu is clicked, it will call Run_Tool() inside which it start a precess and open a form, I also show the codes for progressbar form below, but the progressbar color is grayed, no value is shown.

Would you please take a look where is wrong? thanks!

  Private Sub Run_Tool()

    Dim sAppPath As String = ".\xxxx.exe"
    Dim fileName As String = "XXXXXX.TXT"
    Dim p As New System.Diagnostics.Process()

    Dim rtnStr As String = String.Empty

    p.StartInfo.FileName = Application.StartupPath & "\" & sAppPath
    p.StartInfo.Arguments = fileName

    'Do not use the system shell to start the program this is so we can hide the command dos window
    p.StartInfo.UseShellExecute = False
    p.StartInfo.WorkingDirectory = strOutputFilePath
    ' Show no dos window if false
    p.StartInfo.CreateNoWindow = True
    p.StartInfo.RedirectStandardOutput = True

    Dim progBarFrm As New FormProgressBar
    progBarFrm.Show()


    Try
        p.Start()
    Catch ex As Exception
        ShowValidationMessage("Unexception error is caught, please close and try again.", "Error")
        'p.Kill()
        progBarFrm.Close()
        Return
    End Try


    rtnStr = p.StandardOutput.ReadToEnd()

    ''p.WaitForExit(120000)   '= 1.5 min: 1000 millisecond = 1 second
    ' if the process doesn't complete within 5400 seconds, kill it
    ''If Not p.HasExited Then
    ''p.Kill()
    ''End If

    If rtnStr.Contains(" FAST terminated normally.") = True Then
        rtnStr = rtnStr & vbCrLf & "Please click Postprocess -> View Output File in menu to view the file."
        updateViewMenu()
    End If
    progBarFrm.Close()

    Dim frm As New FormShowFASTResult
    frm.txtFASTResult.Text = rtnStr
    frm.Button1.Select()
    frm.ShowDialog()

End Sub

Source code for the progressbar form as the following

Public Class FormProgressBar

    Private Sub FormProgressBar_Disposed(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Disposed
        Timer1.Stop()
    End Sub



    Private Sub FormProgressBar_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.CenterToScreen()
        ProgressBar1.Minimum = 0
        ProgressBar1.Maximum = 100
        ProgressBar1.Value = 0
        Timer1.Interval = 1
        Timer1.Start()

    End Sub


    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        If ProgressBar1.Value < 100 Then
            ProgressBar1.Value = ProgressBar1.Value + 1
        Else
            ProgressBar1.Value = 0
        End If
    End Sub
End Class

First, ReadToEnd isn't going to give you what you're looking for. It'll block until the console has to something to return, and even then, it'll return block of text, most likely NOT all of the text your app output to the console, and it will only read ONE block of text.

Now, if you want to gather all the text the app outputs, and still have a responsive UI (such as the progress bar redrawing itself), you'll have to read the console output asynchronously.

Something like:

Private Sub StartConsoleRead(ByRef st As Stream)
        Dim rdo As New ReadData
        'rdo.s = _conStream.BaseStream
        rdo.s = st

        Dim consoleReadAsyncCallback As New AsyncCallback(AddressOf ConsoleReadCallback)
        _conStream.BaseStream.BeginRead(rdo.buffer, 0, rdo.buffer.Length, consoleReadAsyncCallback, rdo)
    End Sub

    Private Sub ConsoleReadCallback(ByVal asyncResult As IAsyncResult)
        Dim rdo As ReadData = DirectCast(asyncResult.AsyncState, ReadData)
        Dim bytesRead As Integer = rdo.s.EndRead(asyncResult)
        Dim enc As Encoding = Encoding.ASCII
        Dim s As String = enc.GetString(rdo.buffer, 0, bytesRead)

        CmdOutput.Invoke(UpdateCmdOutputDelegate, New Object() {s})
        StartConsoleRead(rdo.s)
    End Sub
 
 

Public Class ReadData
    Public buffer(20480) As Byte
    Public s As Stream
End Class

Also, you're Timer.Interval on the progress bar form should not be 1. Make it something more reasonable, like 250 to 500 (quarter to half a second). Setting it to one will just make your app hog the CPU.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

If I don't start the process, the progressbar in the form works fine. So the p.Start action hang the progressbar form.

 Private Sub Run_FAST_Tool()

    Dim sAppPath As String = ".\FAST.exe"
    Dim fileName As String = objFASTPrimaryData.FASTPrimaryFileName_FST
    Dim p As New System.Diagnostics.Process()

    Dim rtnStr As String = String.Empty

    p.StartInfo.FileName = Application.StartupPath & "\" & sAppPath
    p.StartInfo.Arguments = fileName

    'Do not use the system shell to start the program this is so we can hide the command dos window
    p.StartInfo.UseShellExecute = False
    p.StartInfo.WorkingDirectory = strOutputFilePath
    ' Show no dos window if false
    p.StartInfo.CreateNoWindow = True
    p.StartInfo.RedirectStandardOutput = True

    Dim progBarFrm As New FormProgressBar
    progBarFrm.Show()
end sub

The reason why your UI thread blocks is not because you started the process. It's blocking because of another line AFTER your call to Start. Your executing some statement that blocks, like WaitForExit, freezing your UI. You cannot do that and expect your UI to update itself.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Thanks, David.

After I remove calling WaitForExit() and ReadToEnd(), the progressbar works now, but the Exited event function OnProcesited is not called, so the progressbar is always shown. How can I make OnProcesited() be called?

Private Sub OnProcesited(ByVal sender As Object, ByVal e As System.EventArgs)
        Dim p As System.Diagnostics.Process
        p = sender

        Dim rtnStr As String = String.Empty
        rtnStr = p.StandardOutput.ReadToEnd()

        If rtnStr.Contains(" FAST terminated normally.") = True Then
            rtnStr = rtnStr & vbCrLf & "Please click Postprocess -> View Output File in menu to view the file."
            updateViewMenu()
        End If
        progBarFrm.Close()
        progBarFrm.Dispose()

        Dim frm As New FormShowFASTResult
        frm.txtFASTResult.Text = rtnStr
        frm.Button1.Select()
        frm.ShowDialog()

    End Sub


    Private Sub Run_Tool()

        Dim sAppPath As String = ".\XXXXX.exe"
        Dim fileName As String = "XXXXX.txt"
        Dim p As New System.Diagnostics.Process()



        p.StartInfo.FileName = Application.StartupPath & "\" & sAppPath
        p.StartInfo.Arguments = fileName

        'Do not use the system shell to start the program this is so we can hide the command dos window
        p.StartInfo.UseShellExecute = False
        p.StartInfo.WorkingDirectory = strOutputFilePath
        ' Show no dos window if false
        p.StartInfo.CreateNoWindow = True
        p.StartInfo.RedirectStandardOutput = True
        p.EnableRaisingEvents = True
        AddHandler p.Exited, AddressOf OnProcesited


        progBarFrm = New FormProgressBar

        Try
            p.Start()

            progBarFrm.Show()
            progBarFrm.Refresh()            
        Catch ex As Exception
            ShowValidationMessage("Unexception error is caught, please close and try again.", "Error")
            
            Return
        End Try    
   End Sub

You can't force it. Your external process just hasn't stopped yet for some reason. Does your external process wait for the user to "Press any key to exit"?? I sure hope not!

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

I have an vb.net application that is being used by multi-users. I execute all sql statements in a seperate block all at one time one after another. Many times it so happens that 2 records (referrenced by 2 persons) are stored in a single id which should be stored in different id.

What should I do to avoid this type of conflict ?

Thanks & Regards,

Use identity columns so that the ID's are generated automatically.

[Managing Your JavaScript Library in ASP.NET]

Thanks AspDotNetDev, Its a high-end reqd to generate ID programmatically and not auto.

Thanks & Regards,

tell your customer that he made an request which is VERY EXPANSIVE to handle - he will agree with identity columns.

I cannot remember: What did I before google?

Well, then you have a serious design flaw in your database. One which will take a redesign to fix and a major overhaul of your code.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Thanks AspDotNet, Thomas, Dave.

>>One which will take a redesign to fix and a major overhaul of your code.
Dave, can you explain a bit on what are you trying to say and how and what factors to look for in the code.

Thanks & Regards,

Simple. Either you don't have a valid primary key (for example, the VIN is unique to each car, but you should never use it as a primary key) or your code is generating the key values (REALLY bad idea!).

In order to fix this you are either going to have to add proper primary keys to your tables, and update your code accordingly or you're going to have to add a layer to your database where every instance of your app is going to have to go through a singleton running on a server to have a primary key generated. Only one instance of your app is going to be able to call this singleton at a time which is going to kill your scalability. Oh, and you're still going to have to update your code to support this.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Thanks Dave for clean and clear explaination and how should I handle this.

Thanks & Regards,

hello guys,

i'm new to VB6 and crystal report, can somebody give tutorial on how to get a value from a textbox to be used in generating a report. this must be done when a button is click.

the scenerio is like this:

i have two textboxes(the from and to date) and a button. below is a crystal report viewer. what i want to do is to generate a report base from the from and to date. i hope you've got what i mean. Smile | :)

any help is appreciated. thanks and God Bless! Smile | :)

Don't repost your question.

I have answered your question in Q/A section. Clickety[^]

thatraja

My Tip/Tricks
My Dad had a Heart Attack on this day so don't...

hey thatraja, do you know how to do this in vb6?

Private Sub Button1_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles Button1.Click

Dim cryRpt As New ReportDocument
cryRpt.Load("PUT CRYSTAL REPORT PATH HERE\CrystalReport1.rpt")

Dim crParameterFieldDefinitions As ParameterFieldDefinitions
Dim crParameterFieldDefinition As ParameterFieldDefinition
Dim crParameterValues As New ParameterValues
Dim crParameterDiscreteValue As New ParameterDiscreteValue

crParameterDiscreteValue.Value = TextBox1.Text
crParameterFieldDefinitions = -
cryRpt.DataDefinition.ParameterFields
crParameterFieldDefinition = _
crParameterFieldDefinitions.Item("Customername")
crParameterValues = crParameterFieldDefinition.CurrentValues

crParameterValues.Clear()
crParameterValues.Add(crParameterDiscreteValue)
crParameterFieldDefinition.ApplyCurrentValues(crParameterValues)

CrystalReportViewer1.ReportSource = cryRpt
CrystalReportViewer1.Refresh()
End Sub

Confused | :confused:

It's very simple, here you go
how to pass parameter in crystal report from vb 6.0[^]

thatraja

My Tip/Tricks
My Dad had a Heart Attack on this day so don't...