Error : ActiveX Control '8856f961-340a-11d0-a96b-00c04fd705a2' Cannot Be Instantiated Because The Current Thread Is Not In A Single-threaded Apartment
Jul 24, 2009
I am trying to create a new thread that will import from an excel spreadsheet, because it was doing all the import before the form actually displayed to the screen. So the user never saw the form while it was importing..In the form's load event I create the thread and start it, but I get this large error:An error occurred creating the form. See Exception.InnerException for details. The error is: ActiveX control '8856f961-340a-11d0-a96b-00c04fd705a2' cannot be instantiated because the current thread is not in a single-threaded apartment.
I am using visual studio 2005 pro on Vista Business?
I'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.
I'm having a small issue; I start a process and when that process exits, I raise an event which removes a control from my form.It all works perfectly until the part where I want to remove a control from my form. Visual Studio gives me a cross-thread exception even though I'm programming single threaded.
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()
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".
I'm using VB.NET. I want to build a large List (Of MyClassOrStructure) that becomes static after its initial population.I'm going to have multiple threads that need to iterate through this list to read data (no writing, inserting, or deleting)
Are there any very bad things that I need to keep an eye out for?
I am trying to load an actixex component in a VB project which was made in Visual C++.n VBA it works fine.In VB6, when I try to load the component on the toolbox I get an "Error 35005"In VB2008 the component can be added to the toolbox, but when I try to place it on the form, the following error occurs: "Failed to import ActiveX control. Please ensure it is properly registered."
I have written a small GUI based vb.net program that speaks to embedded devices via the com port. The GUI code contains a class which all communication to the embedded device is handled through (com port device, communication protocol, parsing info, holding device related info after each read).That class is called EDComms.
I wanted to add a thread so that the EDComms object could run in the background and report back as it downloads logs files and such (It can take a while to get log files from the device sometimes).So. Should I have EDComms inherit from backgroundworker thread? Or should I have a background worker thread as a member of EDComms?Right now I am going with the second choice. The only thing I have to do now is write a func for registering two delegates from the GUI for notifying task progress, and notifying task complete.Or is there a better choice than these two I have presented Perhaps have the thread as a member of the GUI?
I have been working on an activeX control which works on serial port communication. Now I have completed the project and created its setup.exe using Visual studio 6 -> Tools -> Package and Deployment Wizard. Then I installed the control in another PC and in a new project included the control using project -> components. But when I click on the control in the toolbox and then include on the form it gives the following error : delete current link ? and on clicking OK, nothing happens. I tried searching a lot on google but didnt find anything. Another problem is that I have created a string array as a global array which can be accessed by all the methods.I am able to include the same activex control in my own pc when I have created the project. Here it works fine, I am able to access all the methods that I coded in the control, but the String array mentioned above can be accessed in other project. I tried writing Public before the array declaration but it give me the compile error : "Constants. fixed length strings, arrays, user defined types and Declare statements not allowed as Public members of object module." [code]
I have an app that I'm trying to keep single threaded, mostly for reasons to do with simplicity of ongoing maintenance. I've structured it so that I can eventually multi-thread it if need be but I'd rather not at this point. It's semi-real time and does perpetual looping to display a number of different graphs and do various work with both the graph display and the work being hosted in their own respective objects. If you're familiar with the Windows dispatch manager it's that general paradigm run synchronously. And yee haw, it pretty much works at this point and runs fast enough to meet requirements by a happy margin. I have a cosmetic problem that I'd like to solve if I could. When I left-click and move any form around, my graphs stop updating until I release the left click button. I was thinking about a doevents somewhere in the click event catalog.
I have a console application (VB.NET). When it is started, it spawns worker threads to find work in the database and do the task, then look for the next task (A workflow basically).
The problem that I have is that I have my Event Handler in the main thread that spawns the worker threads. Those workers, if they error, raise an event to a public delegate. However my main thread is not detecting these events, and I cannot figure out how to make it. My intention is to do all logging (text/database), email alerts, and restarting the worker to find another task that is not errored. (This will be expanded in the LogErrorMessage routine and such, for now I am just keeping it a simple Console.Writeline so that I can see if the method is being fired or not)
Here is the code around what I am trying to do:
Public Delegate Sub LogDelegateError(ByVal Ex As Exception) Public Class EventLogger Public Event EventError As LogDelegateError
Say I have a code with 3 methods that do some pretty intensive work. Would executing these methods on 3 seperate threads be faster then executing them one after the other on a single core cpu? And what if it's a dual core or HT?
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.
I am new to WPF and custom controls.I have implemented a custom control in VB with WPF and MVVM based on Davids example: [URL]..I have a custom control libary and a reference to my project to implement my control.I implement my contol in the View via XAML:
"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.
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
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.
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:
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
A thread listens for incoming information from a server will add the received string to a custom control (containing a textbox and a listbox, I've called it console). This requires an invoke so I used the following
Dim InvWriteCons As Console = Gary.ChatCons Dim INvWriteText As String = "DEFAULT" Public Sub InvWrite(ByVal cons As Console, ByVal message As String)
I'm learning VB.NET coming from a VB6 and Java background.In my app, I've got a function that validates the fields on a form. All it is doing is reading them, not updating. I've searched and see info about the backgroundWorker class, but all the examples are about updating the fields.I understand the idea of threading and how it works, but have never written code that spawned threads myself. I've always let the language handle it. It seems like a lot of work that I would have to write a sub using the backgroundWorker for every time I wanted to read or update each field. The couple of books I've got that introduce you to the language show you reading or updating the field directly.How do I know what threads are running other than writing the code like I'm used to then running through debugger to figure out what variables are on which thread?
I have a windows form with a progress bar and a button to start/stop the process. I am performing some action when clicked on 'Start' and updating the ProgressBar accordingly and its working fine. But when I try to click on the 'Stop' button when the process is going on, I couldn't access the Window. If I click for multiple times, I am getting (Not Responding) on the titlebar.
Then, I created a thread and run the function (which performs my task and update the ProgressBar) in it. I am getting an error that it could not access the control which is created in another thread.
I am running into an issue with changing properties of controls on a VB.net project that I am working on. The portion of code that I am having trouble with is re-enabling a couple of buttons and a ComboBox after a Threaded operation completes. The point of it is to disable the buttons after clicking the main "run process" type of button (called cmdCrawlSearch) so that the process can run on a new thread while the form is updated with the status. I was able to learn about Thread Safe calls using delegates in order to update the Text property of the TextBox (txtOutput) on the form, and thought that enabling buttons would be just as easy, but when I am trying, I am either getting an "Object reference not set to an instance of an object" exception, or an "Exception has been thrown by the target of an invocation" exception (from the current version of code) with the InnerException being the Object reference exception. I am posting the portions of code related to the issue, then below it is the InnerException name and stack trace. Perhaps I am not using the Delegates correctly (since I still do not fully understand what can and can't be done using a Delegate.) Or there is a better way to do this.
I need some help to understand my options to get this working. I try to update a textbox control by a property-changed event from a class variable. I've digged around for a day and have a vague understanding that this can be solved in three ways:
1. Using some "if InvokeRequired", "Invoke" code in the handler method 2. By programming a special delegate class for this variable 3. By using a databinding directly linking the control (textbox) to the class event
Now.. Are these options correct? And would it be possible to get some help to show these three solutions in actual code (relevant to mine)? I can't seem to manage to sort all the information to a working code. Also, what are the pros and cons of the different solutions?
As my code stands now, it's obviously none of the above, as it gives a cross-thread error, as indicated.
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."
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?
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.
As we know, one STA UI thread creats the controls only canbe accessed in the UI thread in Winform application. And we need to call control.invoke or begininvoke to run the code in the background thread.
Yes, below code in VB.Net , VS 2010 Winform project can throw the exception "Cross-thread operation not valid: Control 'Form1' accessed from a thread other than the thread it was created on."
My program crashes with the following error:Controls created on one thread cannot be parented to a control on a different thread.Purpose of the program is to add a control from a thread outside the main thread.Below is the code Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
I am in a trouble with this error:"An attempt has been made to free an RCW that is in use. The RCW is in use on the active thread or another thread. Attempting to free an in-use RCW can cause corruption or data loss." I am not sure if the RCW-error is related to my problem but I was having this error last January 25. It appears when I am ending my application. I ignored it. The next morning when I resumed coding for my application, the changes I am making does not appear at run-time anymore. Whatever GUI changes I make in my application (at design time), it does not make any effect any longer when I am running the application. What is causing this? I am so afraid if I have to restart my application from the scratch. I have gone far.
I have am using a Twitter streaming class library, and would like to update a listbox when a new tweet is posted. I have it all set up to the point where a message box will show when a tweet comes in, but when I try to insert this tweet into a listbox I get this error: The calling thread cannot access this object because a different thread owns it. I don't know what I need to do in order to insert this tweet.
i know that a single function could not be run until it has finished and is currently not running. what if i have 2 functions within a class, are both of them allowed to run simultaneously? or will running 1 of them prevent both of them from running until it is done?(assume that backgroundworkers and threads are running the functions of this class)
EDIT: plus what if a single function has multiple signatures, is it considered a single function or 2 different functions? could both of them be running at the same time or only 1 is allowed to run between the 2 at any one time?
I have a simple 'Working' form that runs on its own thread to keep the user informed that the application hasn't died during long running operations. In order to get the working form to update I had to insert a DoEvents() call. I'm curious, will this only pump messages for the current thread I'm in, or will it do it for the whole application? I would prefer that the main window stay unresponsive till the operation finishes. Just to be clear, I'm fine with the code I have, but I would like to know how DoEvents() behaves with threads.
Below is the code for the working form. Public Class frmWorking ''' <summary> ''' Creates and starts a new thread to handle the Working Dialog ''' </summary> ''' <returns>The thread of the Working dialog.</returns> [Code] .....