VS 2008 Passing A Queue To A Thread?
Jan 14, 2011I've passed object sucessfully to threads in the past but I'm stumped on this one:-
HTML
Public Class TileDownload
Structure RequiredTileDetails
Public MapID As String
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C# :: FIFO / QUEUE With Buffer And Thread-safe?
Jun 19, 2011I'm receiving tons of statistics data that I need to insert into the db.I would like to implement some kind of Queue or FIFO class that keeps all the dataand when it reaches to a specific count (buffer), it will send that data to the SQL through bulk insert. This should be thread-safe.
View 3 RepliesVS 2008 Passing A Class Method In A New Thread
May 14, 2010I am looking for a way to pass a class method into a new thread. On my form I have a few object that contain methods.
For example obj1.doWork.
Now I want to do
Example
Dim t as new Thread
t = new Thread(AddressOf obj1.doWork)
t.start()
However I get an error on this saying:
Error1Overload resolution failed because no accessible 'New' is most specific for these arguments:
'Public Sub New(start As System.Threading.ParameterizedThreadStart)': Not most specific.
'Public Sub New(start As System.Threading.ThreadStart)': Not most specific.
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))
Thread Safety, Application Design - Console App That Loops Through A Queue And Processes Each Record In A Datatable?
Jul 25, 2011I have a Console app that loops through a queue and processes each record in a datatable. Each process is long and time-consuming (connecting to a remote website, downloading files, reading them and adding them to the database). I'm trying to implement threading for speed's sake but am having cross-threading issues. (The job takes 8 hours or so to run and the cross-threading doesn't start happening until a couple hours into the run.)I'm trying to figure out how to make my code thread safe. I don't update or rely on any non-local variables, and I don't need to return anything. I've tried locking which works but defeats the purpose of the multiple threads. What other things should I be looking for?
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Yes Another 'Passing Variables Thread"
Jan 7, 2012VBasic / VS2008 / .NET 3.5 / Meas Studio 8.5 I've searched and seen a number of convoluted ways of doing this but.... What I am trying to do should be simple and in my mind (and from previous experience) it should work. It doesn't At least not after 10 hours of tweaking, editing, researching....
Straightforward project, 3 components - MainModule, MainForm, CNCNoForm. I declare public var NCPgmNo in the module. I open the CNCNoForm from the MainForm. This form has 2 controls - Numeric Up/Down Box & Close Button. I enter a number in the Num box (read only property is set to false), then assign the value to the var. NCPgmNo in the value-changed event sub. I close the form, returning to the MainForm. The variable does not pass even though it is public and declared in the module. I tried removing it from the Numupdown event and assigned the var before 'me.close'. Still N/G.
If I put a breakpoint right after the line that assigns the var, it is correct. It just does not pass to the MainForm. I started with a textbox, then changed to a Meas. Studio Numeric control, finally Numeric up/down. Same results with all 3. I though the CNCNoForm was broken so I removed it from the project and rebuilt it with a new name (yes name references in the MainForm and MainModule are correct). One other thing. If I call the CNCNoForm repeatedly, it reads the previous value. I am ready to give up computers and take up farming or hiking.
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Passing Data From One Running Thread To Another Running Thread?
Jan 14, 2011I have on timer thread that needs to pass every time a different data to another running thread to make the calculations.
View 5 RepliesPassing Data From A Form Back To A Thread
Sep 20, 2010In a threadpooling situation is it possible for a modal form to be opened and data from that form to be passed back to the thread that opened it ?
View 1 RepliesThreading.thread Addressof Passing Variables
Apr 16, 2012I am trying to pass some status from a IP call in a shared sub to a label on my form. This is the current code that i am using:
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Dynamically Call A Function With Delegates By Passing A String To A Background Thread?
May 20, 2009How do I dynamically call a function with delegates by passing a string to a background thread in VB.NET?
Currently my code is this
Public Sub invertImageBK(ByVal image As Bitmap)
Dim snxl As System.ComponentModel.BackgroundWorker = createBW()
snxl.RunWorkerAsync(New ImageProperties(image.Clone, "invertImage", Nothing))
[Code].....
VS 2008 Adding To Queue Of Process?
Dec 18, 2010I'm trying to Enqueue several processes to a queue of processes.When I do, each process is added, but only the last process name is added. The rest of the names are blank.Here's what I'm doing to test it:
VB.NET
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
[code]......
VS 2008 System.Thread.Thread.Sleep Not Working?
Mar 22, 2010Im trying to do this
[Code]...
But it will just skip to the last status (Label3.Text = "Status: Welcome")
VS 2008 Terminate A Threading.thread Using Thread.abort?
Jun 10, 2010im trying to terminate a threading.thread using thread.abort the thread runs a download connection so is usually in the middle of socket.recieve or socket.send or socket.connect when aborting i just want to terminate the thread no matter what thread.abort raises an MDA excpetion. so i ticked it off in the debug exceptions menu. now it doesnt raise an exception, but the thread simply wont terminate. my program wont close unless i press top in the debugger.i cant pause downloads because i cant terminate the thread this code wasn't working?
Dim vT As Threading.Thread
For Each vT In clsDownloader.DownloadThreads
If Not vT Is Nothing Then
vT.Abort()
[code].....
as for the exception concerning threads being aborted from other threads being dangerous, how is it possible to send a message from a main thread to another thread to abort itself? as far as i know the only way to a abort one thread from another is to just kill it (because i dont know of ways for a thread to communicate with another).
VS 2008 Detect Thread End In Thread Parent
Oct 7, 2010I'm firing a thread to unzip a file. I need some way of indicating to the parent that the unzip thread has ended. I've tried raise event in the unzip thread to a sub in the parent but this runs the sub from the unzip thread. With ApartmentState set to STA, so that I could use a save dialog, this was OK until I displayed a messagebox which was hidden behind the main UI(and whatever I did I could not get it to the front).
View 11 RepliesVS 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
[code]....
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:
[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
Transfering A Queue From One Form To Another Queue In Another Form?
May 14, 2011I have a form that has a queue and i want to transfer that queue to another queue in another form. however when i try to use the elements in the second queue after transfer, I get the error message queue empty!below is my code
First Form
Imports System.Collections.Generic
Public Class Form1
[code].....
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
[code]....
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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Array Like A Queue
Nov 30, 2011I have an array that I'm basically treating like a queue (FIFO)I'm trying to decide the fastest way to implement this.Currently I'm just iterating through and shifting everything up an element and placing the new data @ 0. This was fine when I was dealing with 1000 element arrays, but now I'm moving up to 100k element arrays and it's stalling my code.It has been useful to have the data in array form because I'm using the array.sort method and a few other statistical modifications that use the element number (of the sorted list) to work.I'm not sure if VB lists are (like Java) pointer based, and if so I think that shifting pointers would execute faster than my current approach.My question is, if I did move to a list would it a) be faster, and b) is there a way to call a quick sort from the list class?If the execution time is the same for the array vs. list is there a better way to make a FIFO structure in VB?
View 2 RepliesFirst Time With Queue
Mar 2, 2010how "peek" really operates or something but what I'm trying to do is have 2 separate audio files play one after the other over and over again.I was expecting that I would hear wav1 and wav2 alternate but I only hear wav1 on each cycle.Doesn't peek use the first data then push it to the back without discarding it?Therefore wav2 would be next in line to be played? [code]
View 14 RepliesHas Anyone Seen A .net Email Queue
Jan 30, 2012Has anyone seen a .net email queue? I want to be able to specify the SMTP server to send via, report problems and retry emails if necessary or requested.
View 2 Replies