VS 2010 Managed Thread?
Jun 20, 2012Is there anyway to create an OS or Managed thread, so that it can never be interrupted. Thread/Process priorities are not enough.
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Enumerating Managed Threads Or Determining When A Thread Is Created?
Feb 15, 2010I have need of either enumerating all the managed threads in a application or listen to when a new thread is created. I can not find anyway to do this through searching the web. It strikes me as odd the the IDE can list all the manage threads, but I can't.
If this is not possible, is there clarification as to why this is not possible.
I need to create a shared class in a DLL that will when it receives a signal will stop all the threads currently running, and gracefully exit the application.
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
[Code]...
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.
[Code]...
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
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")
[code].....
Com Dll Vs Native Dll Vs Managed Dll?
May 3, 2010What's the advantages of the above types of dll? Is there any other type?
View 1 RepliesHow To Use Managed Callback
May 12, 2011I am writing classes in VB.Net (both managed). The main class "A" creates an instance of "B". Class "B" must call a method of Class "A". I need to know two things (syntax, etc...):
1. How does class "A" tell class "B" what method to call?
2. How does class "B" call the method?
The method must pass back an array of Shorts (in this particular example), either as a return value, or as a ByRef argument.I don't want to use an event if I don't have to. The execution is timing critical. (I assume event handling involves a lot of overhead by the operating system, but I may be wrong.)
Use Thread In 2010?
Jul 26, 2011i want to use thread in vb.net 2010 and have problem :( after run the project showed this message for meError > " Controls created on one thread cannot be parented to a control on a different thread."
Private Sub Button1_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[code].....
Managed Alternative For GetBestInterface?
Apr 27, 2012I have absolutely no background on programming in C (or any other unmanaged languages for that matter) yet I would like to use the GetBestInterface function from the IP Helper API in my .NET application. I tried to understand how P/invoke calls can be used to make calls to native methods, but there are many things that just don't make sense to me (like how types in managed code map to unmanaged types).
Is there an alternative function somewhere hidden in the System.Net namespace that does roughly the same thing? Or could I write my own alternative using existing base classes combined with some magic? Because that's basically what it seems to me: magic. There is no real explanation for how the method accomplishes what it does as far as I can tell...
I just discovered the LocalEndPoint property on the System.Net.Sockets.Socket class which I think could be quite useful in this. To my understanding it will do the best-interface-picking on my behalf and I'll just need to get the NIC that corresponds to the local endpoint.
Managed Memory Leak?
Jun 13, 2006I am having a very strange memory leak that seems related to databinding. It is very hard to reproduce, so I won't post any code here to do so, but will just describe the problem.We have data entry forms which have controls which bind to custom business objects through a BindingSource object.
View 7 RepliesStart Another EXE In Managed Code?
Apr 10, 2009Is it possible to start another EXE in Managed Code? At this time, all I can do is use:
System.Diagnostics.Process.Start(exeName)
Is there another way to call another EXE within the same project?
VS 2010 - Too Much For The UI Thread To Handle
Jan 22, 2011I've got a form that acts as a progress report for a long running operation, it has a listview on it (which I might be replacing with a DGV soon) that gets updated with progress updates from a background thread that is doing all the work. The method running on the background thread raises events that the form then handles and adds the string passed in to this event to the listview. The method running on the background thread raises progress update events several times a second and for each of these updates the event handler on the form must invoke a method on the UI thread to actually add the item to the listview.
This works fine on my test PC (which has a quad core CPU and 8 GB of RAM) but others have reported that after a while the form goes to the Not Responding state so I'm assuming all of these updates on the UI thread are being requested too often for it to be able to process them all as well as user input.So I'm looking for a better solution and have come up with the following:When the background thread raises these progress updated events, instead of them being added to the listview instantly I add them to a Queue(Of String). Then every second the form would check this queue and remove any items currently in it and add them to the listview - using a Queue(Of T) instead of a List(Of T) should guarantee they come out in the correct order. Both of these operations (adding to the queue and reading/removing from it) would be done under a SyncLock block that would lock on the same object to avoid both threads trying to work with the queue at the same time, so there would still be some contention but I'm hoping it would mean the UI thread only gets busy once a second instead of potentially roughly 30 times a second as it is doing now.Does that sound like a good plan? Can anyone think of a better way of handling this?
VS 2010 C++ Dll Is Not Thread Safe?
Apr 19, 2012I'm calling a c++ dll I made myself - and it appears to be very VERY not thread safe!
I'm referencing it like this
<System.Runtime.InteropServices.DllImport("D:ACS DesktopdcxdcxDebugStringLibrary.dll", EntryPoint:="firstIndexOfKeyword", CallingConvention:=Runtime.InteropServices.CallingConvention.Cdecl)> _
Public Shared Function firstIndexOfKeyword(ByVal s As String, ByVal substr As String(), ByVal substrLength As Integer, ByVal markers As Integer()) As Integer End Function
Is there a way to make this IMPORT create something more threadsafe?
[Code]...
VS 2010 How To Multi-thread
Feb 8, 2011How do i go about multi-threading that, it's just an example project, so i can try and learn from it. As i'm having a hard time understanding JMC's tutorial as it doesn't directly relate to what i'm trying to do [code]When you hit 'Start', the start button is disabled and the Label1 then changes to "Downloading".The data is then downloaded and put into the Textbox1.Label then reads "Complete" Start button is enabled.
View 5 RepliesVS 2010 Run Method On Non-UI Thread?
Dec 11, 2011Usually I use the synchronizationcontext to run methods on my GUI thread from a background thread. But now I need to do it the other way around and the synchronizationcontext class doesn't work on threads that don't have a GUI. What I basically need to do is, if there is anything going on on the thread I want to run my method on, I want to pause or interrupt it and run my method and then let it continue.
View 4 RepliesVS 2010 Seems Like This Is Not Thread Safe
Feb 27, 2012I'm dropping into this function - from several threads - to add an OBJECT to a dictionary collection
Private Delegate Function ReaderRegisterDelegate(ByRef rrFSOb As FSObject) As FSObject
Private Function ReaderRegister(ByRef rrFSOb As FSObject) As FSObject
Try[code].....
It's getting Object reference not set to an instance of an object.The FILEID key being added is F1. F2, F3 and F4 are in the dictionary. Seems like F1 arrived and the object wasn't properly setup. Or thread-slice caused me to see a partially messed with dictionary list?How can I make that a thread safe operation? I thought dropping out to the UI thread was a safe place to mess with code like this? Oddly enough I can go to the immediate window and do this
m_FSObCollection.Add("F" + rrFSOb.FileId.ToString, rrFSOb)
?m_FSObCollection.Count 4
ex.data is a dictionary list that looks like this
directcast(ex.Data , System.Collections.IDictionary).Count 0
VS 2010 Selectedindex And Thread?
Mar 30, 2011So i made this thread using the following
Public DoCopy_thread As New Threading.Thread(AddressOf docopy)
public Sub docopy(ByVal state As Object)
If ListBox2.Items(ListBox1.SelectedIndex) <> "" Then
[code].....
VS 2010 ShowDialog On A Different Thread
Nov 9, 2011[code] For some reason, and I don't know why. The same CustomSplashScreen that had a handle for UpdateText shows to not have a handle when I call .Close().So basically it would show the splashscreen and update the text, but the form would be left opened and not closed like it is supposed to be.
View 2 Replies.net - How GroupBox Control Size Can Be Managed
Jun 12, 2012I have event Button that creates text box in run time.
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim textbox1 As New TextBox
static Dim shiftDown As Integer
static Dim counter As Integer
[code]....
All the text boxes that has been created displayed in GroupBox control dynamically. how GroupBox control size can be managed according to quantity controls inside it.
.net - Pass COM Array To Managed Code?
Apr 7, 2011I have a .Net application (VB in particular, although I would this to be as language agnostic as possible) that uses a COM object (made in C++). I need to implement a event in COM that passes a char array from C++ to .Net. I guess I need to convert the array to a managed array; How can I do this?
View 2 RepliesC# - Finalizers Accessing Managed Stuff
Jul 26, 2010I am well aware that finalizers are typically used to control unmanaged resources. Under what circumstances may a finalizer deal with managed ones? My understanding is that presence in the finalizer queue will prevent any object, or objects strongly referenced thereby, from being collected, but it will not (of course) protect them from finalization. In the normal course of events, once an object is finalized it will be removed from the queue and any objects it references will no longer be protected from collection on the next GC pass. By the time a finalizer is called, the finalizers may have been called for any combination of objects referred to by the object; one cannot rely upon finalizers being called in any particular sequence, but the object references one holds should still be valid.
[Code]...