Keep A Thread Alive?
Oct 17, 2010What is the best way to keep a thread alive
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Check If Port Is Alive?
Sep 18, 2011I am working in Visual Basic 2010 and need to check if a port is alive on an ip.I am currently using this code
If My.Computer.Network.Ping("85.250.180.71") Then
TextBox2.Text = "Server Online"
Else
TextBox2.Text = "Server Offline"
End If
How To Make Animated Gif Alive
Jun 9, 2009I was trying to show an waiting icon when processing a time consuming operation (to let user know something is running behind), but no sure what's the good way to do it? for example, i have a picture box holding this animated Gif, and initially i set it to be invisible, but I want to show it and actually working (alive) when clicking a button, this button will trigger a do loop ending after 1min. [code]
View 17 RepliesKeep Object Alive For Threadpool / Timercallback?
Jun 4, 2009When using teh system.threading.timer or threading.threadpool. queueuserworkitem, you are able to pass an object.
But wouldn't the garbage collector destroy the object even before the callback can be executed?[code]...
Keeping Database Connection Alive?
Nov 22, 2010I have an application that connects to an SQL Server, sometimes we have a networkinterruption of min 10secs during the openconnection , I get a General Network Error when I try to carry out any procedure that communicates with the database afterthe interruption. Even when the connection is closed and reopened, I still get General Network Error. The only way to get the application to function again is to close the Application and reopen it, is there any way I can keep the connection alive?
View 11 RepliesVS 2008 Winsock Can't Keep Connection Alive
Jan 3, 2010I am trying to make a basic server/client program but I ran in a problem.
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When I click connect in the GUI the first state of sock.ctlstate is 6 , connecting then the connected event is triggered and after that the sock.ctlstate is 8 , "Peer is closing the connection". But I dont understand why it does this. I should keep the connection alive to communicate.
VS 2010 Check If SQL Connection Is Alive?
Aug 1, 2011if i go to sql server configuration manager and shutdown the SQL server, the server will be down.
How do i detect for those changes using vb.
Public Sub CheckConnection()
Dim con As New SqlConnection
Dim objCmd As New SqlCommand
[Code]....
I cant make those work because the connection opens and close. WHat i want is to check if the server is alive or dead.
VS 2010 Error - Cross-Thread Operation Not Valid: Control TbPlaca1 Accessed From A Thread Other Than The Thread It Was Created On
Aug 13, 2010In 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".
Cross-thread Operation Not Valid: Control 'Panel1' Accessed From A Thread Other Than The Thread It Was Created On." ?
Nov 3, 2011This 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.
Error - Cross-thread Operation Not Valid: Control 'txt1' Accessed From A Thread Other Than The Thread It Was Created On
Jul 21, 2009I 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.)
Error : Cross-thread Operation Not Valid: Control 'l_users' Accessed From A Thread Other Than The Thread It Was Created On
Jun 21, 2012When 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
Threading Progress Bar In .net - Thread Operation Not Valid Control 'ProgressBar1' Accessed From A Thread Other Than The Thread It Was Created On
Feb 17, 2012Would 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
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Waiting For Threads - Thread.join Suspend Execution Of Code On Calling Thread Until Spawned Thread Finishes Or Is Aborted
Sep 2, 2010My 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).
Cross-thread Operation Not Valid: Control 'Autocad' Accessed From A Thread Other Than The Thread It Was Created On
Jun 6, 2010I 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.
Cross-thread Operation Not Valid: Control 'label2' Accessed From A Thread Other Than The Thread It Was Created On?
Feb 9, 2011My 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.
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Cross-thread Operation Not Valid: Control 'lblStatus' Accessed From A Thread Other Than The Thread It Was Created On
Apr 1, 2010I'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
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Cross-thread Operation Not Valid: Control 'statusHO' Accessed From A Thread Other Than The Thread It Was Created On
Jun 6, 2009My 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:
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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?
Aug 4, 2009Cross-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
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Error Saying "Cross-thread Operation Not Valid: Control 'lblOnline' Accessed From A Thread Other Than The Thread It Was Created On."?
Feb 7, 2011Ok 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")
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Setup - LAN Keep-alive Proxy - "Home Or Small Office Network" Via The Control Panel To Access The Internet
Apr 15, 2012I'm trying to setup sort of a LAN keep-alive proxy...Ex.: My Xbox 360 is connected strait to my computer via an ethernet cable. My computer is connected to the internet via a Wi-Fi adapter. Everything works fine and I can access the internet on the Xbox and computer.
Issue: Every time I start my Xbox I have to set up a "Home or Small Office Network" via the control panel to access the internet. What I would like to do is implement a proxy that when I shutdown the Xbox the LAN doesn't give the "Network Cable Unplugged" notification. I wasn't sure if there was a way to make the connection stay open for so long after it should say unplugged. Such as if I need to restart the system and don't want to have to re-setup the network on the computer.
This is my code to retrieve the network info:
Imports System.Net
Imports System.Net.NetworkInformation
Module Module1
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"Cross-thread Operation Not Valid: Control 'TextBox1' Accessed From A Thread?
Sep 18, 2009When 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 RepliesWrite In Worker Thread In A Data Table And Rich Text Box in Main Thread
Mar 4, 2009I'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 RepliesCreating A Progress Bar That Runs On Another Thread While Keeping Calculation In Main Thread
Nov 12, 2009Preface: 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.
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Cross-thread Operation Not Valid Control 'FormSplash' Accessed From A Thread Other?
Sep 5, 2009I 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?
Cross-thread Operation Not Valid Exception In Single Thread Application?
Nov 14, 2009I 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.
Cross-thread Operation Not Valid: Control 'FormSplash' Accessed From A Thread Other
Sep 5, 2009In 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.
Cross-thread Operation Not Valid: Control 'hiddenrtb2' Accessed From A Thread
Mar 10, 2010im getting this error and i cant figure it out.
Public Sub mlogin()
Invoke(chkb, New Object() {"disable"})
Invoke(d, New Object() {achidrtb, "", "="})
Invoke(d, New Object() {hiddenrtb2, "", "="})
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Call A Method That Started On A Background Thread On The UI Thread Calling BeginInvoke And Passing In A Delegate?
Aug 27, 2011I am trying to call a method that started on a background thread on the UI thread calling BeginInvoke and passing in a delegate as follows:
Dispatcher.BeginInvoke(Function() UpdateApplicationDataUI())
to call this method:
Private Sub UpdateApplicationDataUI()
...
End Sub
However, I get an error in the call to BeginInvoke (the UpdateApplicationDataUI portion of the delegate is stating "Expression does not produce a value").
Me.Dispatcher.BeginInvoke(Function() New Action(AddressOf UpdateApplicationDataUI))
BackgroundWorker Thread Communicate With The Primary UI Thread When Encapsulated In A Class?
Jul 1, 2010A BackgroundWorker thread can pass data to the primary thread. It does it via the RunWorkerCompleted and ProgressChanged events, which I believe run in the primary thread. I would like to encapsulate the BackgroundWorker control in a class so that I can instantiate it more than once. But I don't know how the BGW can then communicate with the primary thread. If the BGW control is within a class, it does not have access to the properties outside the class. In that case, how can the BGW pass data to the thread that instantiated it?
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Current Thread Must Be Set To Single Thread Apartment Sta Mode Before Ole Calls Can B
Apr 21, 2010I'm getting the following error:"Current thread must be set to single thread apartment sta mode before ole calls can be made"
I am using Speech.Recognition.SpeechRecognizer and using it to open various dialog boxes. It works fine for the first few but on the third one when it calls the InitializeComponent in the Dialog's New, it throws the above error.
Anybody have any clue what causes this or how to fix it? The SpeechRecognizer seems to run on its own thread, so that seems to be at the root of the problem. If I open thedialog with a button click I don't get an error.
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