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.
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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've been trying to create a timer that waits for another timer to finish with its coding and, when it's finished, executes a series of code before stopping itself.
This isn't the code for the actual program I wanted to implement this self-stopping timer in, but it's simple and has the exact same problem:
Public Class Form1
Private Synchro As New Timer()
Private Sub MeLoad() Handles Me.Load
[Code].....
The idea here is that it's suppose to (using a timer) show the messagebox ONCE and ONLY once per button click. However, what seems to happen (despite the fact that I have 4 ways of trying to tell it to stop) is that the program creates multiple messageboxes until there are a total of about 49 messageboxes on the screen at the same time. I don't know if I'm using the wrong event (unlikely as Tick seems to be the only timer event) or there's a way of stopping the timer that I don't know.
I have an application which has a thread running which makes constant calls to a server. Occasionally, the calls become unresponsive, and I would like to stop and then restart the thread.How do I do this? I can't use mythread.Abort() because then it doesn't allow me to start the thread again.
View 5 RepliesI'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 RepliesIve created a trial application , but how do i stop that application from running again on the same ip address? Just so the user cant re-install it and use it again.
View 15 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 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 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.
I have a thread in an application which calls a sub routine Main(). The Main sub routine in turn call several sub routines/functions from with the same module,several different classes in the same application. Also some sub routines/functions call routines from a class library. Now say the routine/function in class library goes into a infinite loop and never returns. I would like my thread in the application to raise a event and display message to the users about the infinite loop. I am giving some sample code for the application.
Imports System.Threading
Module VMain
Public gbSuspend As Boolean
[CODE]...
My routine to check for updates is run as a separate process. Exiting the application is required to update, so a dialog asks the user, when an update is found, if they want to exit now. f they do, the code (from the update thread) calls Application.Exit().However, if the FormClosed event of any form that needs to be closed needs to access its controls, an invalid cross-thread operation is detected (which sounds pretty logical).
View 1 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.
I am working on a Windows Service application in VB.net 2008. The main objective of the application is to monitor starting and stopping of applications listed in a file. I build the service as system level by using
mManagementStartWatcher = New ManagementEventWatcher("Select * From Win32_ProcessStartTrace")
AddHandler mManagementStartWatcher.EventArrived, AddressOf
[code].....
Say i have an application (WPF/WinForm/Whatever)What happens to a thread created via:
Dim t As Thread t = New Thread(AddressOf Me.AddRecords) t.Start()
I am trying to make an application with a start button and a stop button on a stop watch program. These are the codes I am using but my seconds on the stop watch don't start.
Public Form Dim intSecond As Integer = 0
Form 1
Private
Dim intSecond As Integer = 0
intSecond +=1
[Code]...
After I write my code and try to run the program, the seconds will not start,
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]....
