I have an app in vb net 2005 which has code similar to' start external thread ShowRandom Images.start Open database & do other preliminary setup 'abort thread ShowRandom Images. abort 99 times out of 100 I never get a problem, but if system appears to be slow or other heavy processing, I get "Thread being aborted"..How can I trap or ensure the error message does not get to my users
View 6 RepliesMy 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'm using the code below in a separate (background) thread, in order to read parts from a file, so they can be uploaded.
The problem is that when the user stops the upload, the thread is sometimes aborted while it's still reading from the file. This keeps the file locked and when the user starts the upload again, the following message appears.[code]...
I am using System.IO.Ports.SerialPort in my project. This is the first time I am using this component.
Let me explain the issue. My desktop is connected to a weigh scale where I am taking the readings through the COM port. In a particular function I need to give new settings (Baud, Parity, StopBits, DataBits) to the serialport. So I am closing the existing object, and opening it again with new settings.
I am getting "The I/O operation has been aborted because of either a thread exit or an application request." exception while closing the serial port. The code is follows
If frmMDI.SerialPortReader.IsOpen Then
frmMDI.SerialPortReader.Close() //Exception comes here
End If
I've a VB.NET code called when I need to delete an object from DB. On Page_load I check if it's not post back (to prevent a manual refresh) and, after the deletion of the object I redirect to the caller page using Response.redirect. At this point my code raise an
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when I came across an error (The I/O operation has been aborted because of either a thread exit or an application request) regarding this code:
"Private Sub SerialPort1_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
If closingdown = False Then
received = SerialPort1.ReadTo(vbCr & "R") 'Motion port receiving data. needs a vbCR & "R" is sensor out is an ASCII "R" followed by three characters(which is the distance measured)
End If"
It only occurred on "received = SerialPort1.ReadTo(vbCr & "R")".
However sometimes this error is not shown, but most of the time it does occur.
This error only occur when i want to close the form. Other than that it's perfectly alright.
A user will enter a name and a text score of a student. The names and scores are saved in a list box and once they are stored I click 'show the array' and I get a parallel array filled with the names and scores.
I need to error trap the text box's so that when the user inputs a number its a number between 0 and 100. IF its not it needs to end the button click event.[code]...
What I want is a Global Error Trap that will not stop code execution. What I have found is examples where each module requires some code or a Try block. I need it to be totally generic. Everything from UnHandledExceptions to conversion errors.
If I have to use try blocks all over the place then it is not Global Error Trapping.
I need code at the highest level possible that will always catch any and all errors reported by VB.[code]...
I am working on an app that uses a third-party charting component.It is a .Net component. There have been some occasions when exceptions have occurred inside the third-party component code, but my try/catch is not trapping them.Should they get trapped?My code is structured roughly like this:[code]I have since found and fixed what was causing the exceptions, but I would have thought that this should trap them. What happens when I run in the IDE is that it crashes and Visual Studio throws up a page telling me there is no code available to debug, and no disassembly available.Fair enough, but I repeat - why doesn't the exception get trapped?
View 4 Repliesi am creating an activeX control... in this control i want to manage what the tab key does. i may a user interface that allows tabs in the textbox or it might move the user to the next screen. i have everything working in the IDE, but when my activeX is loaded into the 3rd party application the tabs no longer trigger the key down event. i assume this is because the parent application has tab stops is there a way on a control by control basis to stop the normal execution of tabs?
View 1 RepliesI am having problems clicking a link on a page.I was thinking of trapping the click events in the web browser when I manually click the link to see if it uses any other post variables from that page or what happens when I click the link.
View 7 RepliesIn my code I'm using the Try-Catch functionality. All errors are written to the event viewer.I do it now with identifying the lines of code with a number.
View 7 RepliesFor a NumericUpDown control in VB 2005, how do I distinguish between a change to the numeric value made by the user (by changing the text or clicking the up or down arrows), and a change made internally by my code? The "Scroll" event works for user changes to the TrackBar control, but not for me on the UpDown control, and the ValueChanged event doesn't distinguish the source of the change.
View 8 RepliesIs there anything I have to do to trap wheel mouse events?I have a panel and can trap the MyPanel_MouseMove events but not the MyPanel_MouseWheel events.In VB6 you needed to add wheel hook & unhook commands - do I have to do anything for VB2008?
View 5 Replieswhile looping through a short XML file called from xmltextreader retrieved from a webservice, I'm repeatedly getting the error: The request was aborted: The connection was closed unexpectedly. it constantly dies a row or two from completing the parsing.here's my short code:Code:
'Get the principal-id for Group Dim url As String = "https://xxxxx.acrobat.com/api/xml?action=principal-list&session=" & strCookie xmlRead = WebRequestToServer(url) Do While xmlRead.Read If xmlRead.NodeType = XmlNodeType.Element Then If xmlRead.Name = "principal" Then strGroupID = xmlRead.GetAttribute("principal-
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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()
[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
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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.
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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
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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
Try
If Me.CompanyNameTextBox.Text.Length = 0 Then
MessageBox.Show(
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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]....
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].....
I had a problem getting a VB.NET web service client to receive the response object from a Java web service.In the process of posting this question someone from another department volunteered some code written for a similar situation.I couldn't find this anywhere on the net so I'm completing my question to help others out.[code]The web service is Apache CXF with some Spring elements mixed in.
View 1 RepliesI'm making a kiosk style desktop replacement.
Im using setwindowshookex to run a callback system to trap the keys just trapping "windows" key atm.
if I step through just as the program goes the the keyboardcallback function declaration line it pauses for seconds before moving to the next line. This directly precedes the new variable declaration of the callback variable
While running this leads to only 1 press of the "windows" keys causing several hits of the "youve pressed windows key warning" sometimes 4 or 5 times with large pauses inbetween inwhich the window is unresponsive.
The Start menu is normally blocked however occasionally during the unresonsive times it might pop up but this is rare.
Or common reasons/solutions to setwindowshookex being slow Anyone know alternative method of blocking all hotkeys (apart from the 3finger salute i understand that, that is not accessible)?
I have a program that sends some data on a networkstream through a tcp connection.
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