I'm having a hard time stopping a thread. Whenever i close my main form the application doesn't stop because there is a thread still running. I tried every solution I can find in the web but i can't make it work.[code]...
View 8 RepliesI have the following code running in a thread to enumerate the local machines in the active directory. This takes some time to complete (about 5-10 seconds) so if the user quits the application before the enum is complete the application takes 5-10 seconds to quit. I tried thread.abort but because it is waiting for For Each SubChildEntry In SubParentEntry.Children to complete it doesn't abort until this returns.
Dim childEntry As DirectoryEntry = Nothing
Dim ParentEntry As New DirectoryEntry
ParentEntry.Path = "WinNT:"
[code].....
I have an application in which there is a do...loop. I need the do...loop to perform some code and then stop for .1 of a second. When i try using System.Threading.Thread.sleep(), a wait cursot comes up and the application stops working. I was wondering if there was any way to get the thread to stop without stopping the application.
View 5 RepliesI have a VB .Net service, which uses System.Threading instead of a timer to basically do what a timer should do. My problem is stopping the service while the thread is in its sleep state. See the code below:
Imports System.Threading
Public Class AService
Private stopping As Boolean[code].....
If say 1 minutes after the service starts, it can not be stopped until its 15 minute interval ticks and the thread wakes. Is there any way to catch the signal that the service is attempting to stop, and interrupt the thread?
How can I close or stop a thread. For example
Dim trlisten As Thread
Is it trlisten.Stop? or trlisten.Close? or what?
I'm currently making a bot that points and clicks. It works great! The only problem I have is stopping the bot.How could I make a shortcut key that stops the bot while it's running?
View 14 RepliesI'm working with vb.net 3.5SP1 /VS2008. I'm familiar with windows threads from C++ but I didn't do it since the 90s.I have 5 threadpool calls (ThreadPool.QueueUserWorkItem) that do some complex work (they read info from different web pages, regular expressions, etc) and each updates different columns in a data-grid view. They pause for 1 second between each web read with thread.sleep (not to overload the server). My issue is that some of the threads do not complete. I get for example 3 results when I should have 8. Sometimes it works fine. This is an older 3.0Ghz HT machine, I want to test it on the lowest common denominator(and that is all I have ). I tried using Monitor.Enter(ListView1)it seems to help but it is hard to tell. I tried using the thread debug window but it is not really helpful, it seems do disappear during execution. If I remove the threads I always get my data. I'm wondering if something is being blocked? Is there a way to debug this?
Also, does thread.sleep(x) stop all threads or just the thread that the statement is executed in?
My program starts a lengthy background operation in a separate thread, and the main thread makes the ProgressBar start scrolling. My question is, how do I tell the main thread how to know when the background thread has stopped, so it can turn off the ProgressBar?
View 8 RepliesI have a vb.net application that uses threads to asynchronously process some tasks in a "Scheduled Task" (console application).We are limiting this app to run 10 threads at once, like so:
(pseudo-code)
- create a generic list of 10 threads
- spawn off the threadproc for each one
- do a thread.join statement for each thread to wait for the longest running one to complete.
What i am finding is that if the code called by the threadproc contains any "Debug.Writeline" or "Trace.Traceinformation" statements, the thread hangs. I can see the thread in the Debug - Windows - Threads window, and switch to it, but it highlights the debug.writeline statement and never gets past it. is there something special about the Debug or Trace statements that make them non-thread-safe? Any idea why this would hang things up? If I leave the debug statement in, the thread never completes. If I take the debug statement out, the thread completes in less than 5 seconds.
In one application, I need use 4 simultaneous threads.When the threads finished, I need to update the text of a TextBox.So, I create 4 Textbox, and I wanna the threads change the text to FINISHED.Each thread change one distinct TB.I use this "example"
Dim Terminados As Integer = 0
Private Sub frmEnviarMensagem_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Timer1.Enabled = True
Timer1.Start()
[code]....
The problem is, I have an error in the red lines.The error is: INVALIDOPERATIONEXCEPTION "Cross-Thread operation not valid: Control tbPlaca1 Accessed from a thread other than the thread it was created on."I don't use cross threading. Each TB only was accessed for the correspondent thread, and for the "main program".
This is the error message I am getting:
"Cross-thread operation not valid: Control 'Panel1' accessed from a thread other than the thread it was created on." The reason I am getting this error is because I am opening up a new form and then calling these three things:
Panel1.Show()
Label1.Show()
Label2.Show()
why I get this error message because it doesn't occur normally if I open Form2 after closing Form1, it only occurs when I open Form2 after closing Form4.
I have done a program using vb2005 to display reading from my microcontroller bs2 board but have encountered some problems. My code are as follows.
Dim Stop_Rx As Boolean
Private Sub btnRead_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnRead.Click
SerialPort1.Open()
[code]....
I've encounter an error which is, (Cross-thread operation not valid: Control 'txt1' accessed from a thread other than the thread it was created on.)
When my client try to connect to server I'm getting this error : Cross-thread operation not valid: Control 'l_users' accessed from a thread other than the thread it was created on.
Private Sub _socketManager_onConnectionAccept(ByVal SocketID As String) Handles _socketManager.onConnectionAccept
l_Users.Items.Add(SocketID)
End Sub
Would anyone be able to help me here please. I'm fairly new to VB.net and threading so im just trying to figure out what is happening.When I debug this I am getting the error thread operation not valid: Control 'ProgressBar1' accessed from a thread other than the thread it was created on.
I'm a little lost as to why the error is occuring or how to fix it. I've had to put the progress bar in a separate thread otherwise the GUI crashes
[Code]...
My understanding is that thread.join will suspend the execution of code on the calling thread until the spawned thread finishes or is aborted...
With that in mind, I tried this:
For i = 1 to 50
threads = New Thread(AddressOf test)
threads.IsBackground = True
threads.SetApartmentState(ApartmentState.STA)
[CODE]...
However, the rest of the code runs when the loop finishes, not waiting for all the spawned threads to finish. Since the rest of the code needs the threads to finish (otherwise the rest will error).
I have written an application that loads a form - frmCad as well as AutoCad. It does this via a class which detects when AutoCad quits.
Friend Class CadApp Private WithEvents AppObject As AcadApplication... Private Sub AppObject_BeginQuit(ByRef Cancel As Boolean) Handles AppObject.BeginQuit RaiseEvent Quit() End SubEnd Class
My main class loads frmCad as well as CadApp.
Public Class Cad Private WithEvents frmCad As CadForm Private WithEvents app As CadApp... Public Sub ShowForm() If frmCad Is Nothing Then frmCad = New CadForm frmCad.Visible = True End Sub... Private Sub app_Quit() Handles app.Quit frmCad.Dispose() frmCad = Nothing .... End Sub
When I debug the program, it stops at frmCad.Dispose()The program continues to execute, but all the code after it fails to work.Looking more carefully I get an error message which contains:-Cross-thread operation not valid: Control 'Autocad' accessed from a thread other than the thread it was created on.
My error:Cross-thread operation not valid: Control 'label2' accessed from a thread other than the thread it was created on. I want to be able to give my Public RunBot() sub access to edit Labels, buttons, etc without an error.
[Code]...
I'm getting the 'System.InvalidOperationException' error on acccessing a thread from other than where it was created. My code is:
'Required by the Windows Form Designer
Public components As System.ComponentModel.IContainer ' changed from private
[code]....
My problem is Cross-thread operation not valid: Control 'statusHO' accessed from a thread other than the thread it was created on.
System.InvalidOperationException was unhandled
Message="Cross-thread operation not valid: Control 'statusHO' accessed from a thread other than the thread it was created on."
Source="System.Windows.Forms"
StackTrace:
[Code]...
i used it and it works fine then. but as it is mentioned its not a good practice to use it. So what should i do? is it ok if i use this as i am not able to use correct practice. Mine application is not for enterprise purpose. its just my class project, and it works fine even if i put application working in background. System works ok. I dont know how to correct this error.As i dont have that much knowlege of threads.
So please guide me how to fix this in correct way otherwise i am force to go for bad programming practice
Please refer to Windows Mobile Developer Center > Smart Device Development Forums > Windows Mobile Development > Appendtext not working for all my code details
Cross-thread operation not valid: Control 'lv1' accessed from a thread other than the thread it was created on.
Dim lvi As ListViewItem
For Each lvi In lv1.Items
[code]....
So I am hacking together an app which listens to traffic using SharpPcap library, it reconstructs the packets from sessions using the code from TpcRcon.
Listening and reconstructing part work on their own . What I want is on each packet arrival main window gets an event so it can display the packet , and when session is reconstructed display a complete packet (I am interested in HTTP ones) . -That is where it breaks with weird symptoms: for example right now it does not stop on invoking stop listening method - the sharppcap library function hangs there forever waiting on this line of code : m_pcapThreadEvent.WaitOne();//wait for the 'stopped' signal from thread
I also had it not working and crashing in sharppcap function because I had omitted one parameter in form delegate- which makes no sense, because form delegate does not deal with packet capture at all and only reacts on "New Packet" event from my "Listener" class (which is only there to notify main form)
My app starts as module main instancing class "Listener". MainForm has it
registered as friend with event and handles even "New Packet"
Main Form:
Private Sub uiListenStart_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btListenStart.Click
aLogger.AddMessage("Started Listening")
[Code]....
Ok i have a Form with the following
Private Sub frmMain_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
txtNotepad.Text = LoadFile("notes.txt")
[code].....
Alright, so I'm still working on the slot machine. I have three timers all independently going for my three "wheels" of the slot machine.
My issue, is that I'm trying to make a Stop button to stop each timer one at a time, and I'm not understanding why this code isn't working. The logic completely makes sense, and the first "wheel" stops when I click the button, however, it doesnt appear to stop the other two timers.
CODE:
I have a simple application that use thread pool to read a file and input the data into a listbox. I want to be able to stop threadpool from running after clicking a stop button. How do I stop threadpool? Here is the code for my application below:
Imports System.Threading
Public Class Form1
Private Delegate Sub StringDelegate(ByVal text As String)
[Code]....
I created a form and have the variable inputs for 4 motor run statements. Then with a start button the script starts and it is surrounded by a for next statement to loop 10 times. It works fine but if i need to stop the execution of the script with a stop button. I put the stop in a new section but of course does not work to do a motor stop. It just causes the exe to not respond till the loop is complete. Just need to be able to stop the Run1_Click button section.
Edit:I do not mind if it finishes the 4 motor run commands and then stops execution of the loop. So need to figure out a way to trigger a stop from a button on the form to stop the cycle. For the future the loop will be a variable integer input so 10 will not be the standard.
Edit::Does a ' Do ' statement sound like the thing to use? If so how and where would I place that? Have a Stop button on the form and it would stop after the 4th motor run command.
#End Region
Declare Function InitStp Lib "stp.dll" () As Integer
Declare Function RunMotor1 Lib "stp.dll" (ByVal steps As Integer, ByVal interval As Integer, ByVal direction As Integer, ByVal outputs As Integer) As Boolean
[code]....
When i run the program i am getting the following error in this line TextBox1.Text &= "File Created: " & FullPath & vbCrLf"Cross-thread operation not valid: Control 'TextBox1' accessed from a thread other than the thread it was created on."
View 13 RepliesI'm creating a Client Server application which involves theServer running some scripts in clients and getting back results in an automated way. In Server, other than Main thread, i have 2 worker threads, a) one monitoring response from clients and b) the other scheduling next available job to respective client which executes that job. The issue here is ,I want these worker threads to write the status of their work in the UI(which comes under Main Thread). Also i need to write things in worker thread in a Data table and Rich Text Box in Main thread. But, I can't do so, since it has been blocked to access one thread's function or property directly from others. Is there any work around to do this?
View 8 RepliesPreface: I know this is an unusual/improper way to do this. I can do this with a "real" ShowDialog(), background worker/thread, and so on. I am trying to do specifically what I describe here, even if it is ugly. If this is impossible for X reason, I have created a fancy progress dialog for some of our long running operations. I need to have this dialog shown on a new thread while having processing continue on the calling (UI in most cases) thread.
[Code]...
I need your help on the following. In debugging mode only the program is stopping to the following line "My.Forms.FormMain.HelpProviderMain.HelpNamespace = "Reports.chm"" with the following error ""An error occurred creating the form. See Exception.InnerException for details. The error is: Cross-thread operation not valid: Control 'FormSplash' accessed from a thread other than the thread it was created on.""
I noticed that when I am putting NONE in SPLASH screen option in the properties of the project, there is no problem.I am no familiar with treating that's why can you give me detail instruction how to overcome this annoying problem?
I am getting this exception: Cross-thread operation not valid: Control 'TextBoxOutput' accessed from a thread other than the thread it was created on. in a VB 2008 Windows Forms application that I havent specifically made multi-threaded. I have create a sub called Out() like this:
Private Sub Out(ByVal inString As String)
Me.TextBoxOutput.Text += (Me.TextBoxOutput.Text & inString & vbNewLine)
Me.TextBoxOutput.SelectionStart = Me.TextBoxOutput.Text.Length
Me.TextBoxOutput.ScrollToCaret()
End Sub
and I call it from various events to log messages I am getting from my pbx, which I use a third party open source dll to access. The interesting thing to me is that if I run the deployed application (ie, not in the VS IDE) I do not get any exceptions, it's only from within the IDE.if I add the line: Control.CheckForIllegalCrossThreadCalls = False to the form's constructor, the exceptions stop, but a) this seems like a hacky way to get around the issue and b) the application seems to hang sometimes when I have it set this way.