In my program I have a thread in the background that runs an infinite while loop. If I want to terminate the thread, I break the while loop, and the thread runs to a stop. However, if close the form without stopping the thread, it just keeps running. I tried both aborting the thread and exiting the while loop in the closing form method, but without succes.
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I am currently working on a project that has a splashscreen This splash screen is designed to be shown when the main form begins to load its requirements, and then closes once it has loaded... Currently it works like so:
Private Sub frmMain_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
frmSplash.Show()
dolotsofloading()
frmSplash.Close()
End Sub
[Code]...
I have form1 and form2. A button on Form1 calls a thread background process (below). That process processes the command and when its done should close form2. I'm opening form2 within the current thread but trying to close it in the background thread. This is because if i close it in the current thread it closes immediately. I included the 2 functions below and what I have tried in the inline comments. Form2 is a simple form, basically just an animated gif. It is to show the user that something is happening(like a status bar) then close when its complete. I tried running different priorities instead of different threads but due to the results threading seems to behave the best. I'd like to keep access to both forms during the process, the pc, and screen refreshes realtime.[code]
View 2 RepliesI seem to have a problem in finding a solution to threads.I am opening a .PDF file via an <iframe> using vb.net. Then the file is opened, it is then moved to another location. But for some reason I am unable to move the file because it "The process cannot access the file because it is being used by another process." The only way round it i have found is to kill the process for Adobe Acrobat, so the file is released. Even if i fill the iframe with something else.How would I close the file, and stop that particular file from being accessed before the move ?
View 6 Replies1. I am closing the form which started the thread inside the thread. There are no errors , but Is it safe ?
2. The thread starts at click of a button . If same button is clicked again , the thread is aborted. Should the thread be made Background or foreground ? it is working either way.
my code :
Private Sub BtnOk_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnOk.Click
m_Thread = New System.Threading.Thread(AddressOf MyFunction)
m_Thread.IsBackground = True
[code]....
I want to be able to kill an application (iFix) using VB 2008 express. How can this be done. I have used the following in the past with in iFix using its own VBA but I want to be able to do it with an app that I am creating.[code]...
View 13 RepliesIn 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
I am creating an updater for my program that runs in a separate process. I need it to be able to close the program it's updating before running the new setup, but I do not want to use Process.Kill() because that could cause data loss. How can I safely close another application, as if the user had clicked the "X"?
View 2 RepliesNew connections will be remembered. [code] keeps saying that it does not exist, and yes TextBox1.text = "winxp-base02".It clearly shows in CMD with net use that the connection does exist, anyone know Why I can't kill IPC$ or from what you see should work?
View 2 RepliesI want to check whether a process running in remote computer or not and if it is running, kill it.I am using following code but, it gives error "Couldn't connect to remote machine". Do I need to do any security settings in the remote pc where I am connecting?
For Each myObj As Process In System.Diagnostics.Process.GetProcesses("192.168.0.138")
If myObj.ProcessName.Equals("HomeAlarm System.exe") Then
myObj.Kill()
End If
Next
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]....
I am trying to kill the duplicate fields in a DataGridView. I have it alphabetize all the items in the DGV and then compare each item down the DGV as long as it is either equal to or alphabetically lower than the next item in the DGV.Here is the code I'm using:
Do While X < data.Rows.Count - 1
' Compare 2 items next to eachother
compareResult = String.Compare(data.Item(0, X).Value, data.Item(0, Y).Value, True)
' Update the status
[Code]...
As I run it through more largely populated DGVs (200k items), I run into an InvalidOperationException saying that rowIndex=190000 (just some high number) is an invalid value for rowIndex.The error seems to appear more or less randomly.When tested on DGVs with 20k items, it seems to complete fine (though it may just be luck and the error isn't popping up).
I want to be able to disable Alt+F4 and the X button. I was able to do that, but it disabled Close() too. I want my app to be able to terminate its own process. How would I do that?
View 2 RepliesForm1 is a mdi container. It has a bunch of forms that can load inside of it as mdi children. If I close each open form inside the form1, and then click the red X at the top right, application exits fine.If I click the red X without closing the forms inside I get: An unhandled exception of type 'System.CannotUnloadAppDomainException' occurred in mscorlib.dll
Additional information: Error while unloading appdomain. (Exception from HRESULT: 0x80131015) However I can break from it. How do I get the application to not show that error? What must I do to fix those inside forms or close when the red x is clicked?
Dim frm As Form
For Each frm In Forms
Set frm = Nothing
Next frm
The above code is what I used in VB6 to close all forms associated with my programs before my program closed. I have been searching for information on how to make sure all forms are closed when closing a VB2008 program.
I have seen info on using the Project Property Shutdown mode When startup form closes and I currently have this set.
Is this all that is really necessary? Will the garbage disposal close everything else to free up RAM?
Also, if I have several forms open and want to close all from the main form without closing each one individually, what is the best approach? Is there a collection like in VB6, go through the collection, compare it to the name of the main form and close it if it is not the main form?
How is that possible? I want to check all the software a few seconds if the program has tripled works and then you close it automatically[code]...
View 8 RepliesI am developing an application which launch an external windows app, ei called APL.exe Also, this APL.exe launch two console utils, ie. named CON1.exe and CON2.exe I would like to know if is there any way, after APL.exe has died, of killing CON1.exe and CON2.exe, because there is a small possibility that they will not died completly after APL.exe has exited.Also there is another requirement. My final app version could be executed twice in the same machine, so there could be two instances of CON1.exe and CON2.exe, and because this I need a way to kill them not by process name, but knowing which of them has been launched by my current application instance.
View 5 RepliesI'm using the namespace System.Diagnostics. I need to check if there is a Windows process called "gospeakx.exe". If exist the "gospeakx.exe" process, end it. Does anyone know how I can do this?
View 1 RepliesWhen starting my application, I have a couple of classes which are required to read certain files in order to create a set of default data. The logical place (to me) to do this is in a Shared class constructor; the idea would be to throw a class-level event if the reading of the defaults file fails. Unfortunately, this does not work as attempting to access such an event, in order to attach a handler to it, fires the class constructor before the event has been attached. In a failing case, the constructor starts, fires the fail event, the constructor completes, and then the event handler is attached, after the event has fired.
The only other solution I can think of is to give the class a "typeInitialisedSuccessfully" boolean property and put a try/catch block around every call to construct an instance of the class, which seems unnecessarily kludgey to me. Can someone suggest a more elegant solution?
EDIT: Because this is a fundamental Class, used in one form or another across nearly all of our software tools, I would greatly prefer a solution that will notify future programmers that the type initialiser needs to be called, which is why I initially went towards the Shared Constructor as a solution.
I have the following code to close a form which is a child. The problem is that when it closes, it closes the MDI parent too.
Private Sub frmTransaction_Closing(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
If ListView1.Items.Count >= 1 Then
[Code]....
Ok 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].....
