Thread That Repeats Certain Sub
Apr 14, 2011I'm trying to create and start a thread(s) that execute certain sub continuously.[code]
View 4 RepliesI'm trying to create and start a thread(s) that execute certain sub continuously.[code]
View 4 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'm down to the final coding on one of my projects, when i notice that the backgroundworker behaved strange. For each time i run the backgroundworker, it repeated it self one more time, and the new time, it repeated one more time.
So, if i run the worker a third time, it would repeat it self 3 times.
First run: Runs one time
Second run: runs twice
Third run: run 3 times
And so on.
So, i'll post all the code from that form.
Here goes.
CODE:
I dont have anything to handle it when its full but it never gets there. I need it to pick a random number from 1 to 60 that doesn't repeat but i keep getting a system.stackoverflowexception and it will repeat numbers.
num = RandomNumber.Next(usedcountries.Length - 1)
'TextBox1.Text = num
If first = True Then
usedcountries(y) = num[code]..............
I am a complete newbie at vb trying to design a quiz where the user will be presented randomised images to grade. I am at the stage of writing code to randomise image without repeating. Images are stored in imagelist (not sure if this is the best way to 100 images - I've read a few posts about limitations of imagelist) and are being randomly presented in picturebox. At the moment my code loops around continuously with repeats. However I would like it to present images randomly without repeating. Here's the randomise snippet of my code. Hellllppp! it loops round and I'm not sure about to remove images.
[Code]...
I've seen a few other people ask this question and have tried the responses that they have had with no luck.
I am trying to use the randomize command to generate a truly random number. What I am doing is reading an access table to get the number of records, then seed the randomize statement with that number of records with the top range for a random number. I then use the number to select the record I want from that table via it's ID number. My code for doing that is working great.... except that it is always calling on the same record each time through the loop. Here is the code.
[Code]...
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]....
Here's the code:
'Determine and Display User-Selected Major Chord
If Me.tvChordExpressions.SelectedNode.Name = "NodeAMajor" Then
'display chords
Me.pbMain.Load("D:Visual Studio 2010ProjectsMusicaMusicaChordsMajorA.jpg")
'play A Major Chord
My.Computer.Audio.Play(Application.StartupPath & "Audio ChordsAMaj+10.wav")
End If
[Code]...
this works great, however the problem is that the audio file (A Major in this example) will repeat playing every 4-5 seconds. Question?...Why and How do I stop this?
I am trying to design a quiz where the user will be presented randomised images to grade. I am at the stage of writing code to randomise image without repeating.
Images are stored in imagelist (not sure if this is the best way to 100 images) and are being randomly presented in picturebox. At the moment my code loops around
continuously with repeats. However I would like it to present images
randomly without repeating. Here's the randomise snippet of my code.[code...]
I'm trying to shuffle a Euchre Deck and it works but I feel like I'm cheating. Is there a more concise way to randomize a list of numbers 1 - 24 and have no repeats? ex. 14, 3, 18, 23...
Dim Deck() As String = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24}
Dim A As New Random
Dim B As Integer = A.Next(0, 24)
Deck(B) = "9 of Clubs"
[code]....
I am trying to write a program that gives a random number with out repeats the limit is 60 right now. I get a System.StackOverflowException error randomly sometimes it could be 5 numbers in it could be 50. also it will repeat some numbers. Ive been looking over it and it looks like it should work to me idk why its not.
BTNgen calls this sub.
Private Sub gen()
If y = usedcountries.Length - 1 Then
BTNgen.Enabled = False
[Code]....
I'm trying to make a Bulls and Cows type game, I was able to do it fairly easily with javaScript, but VB is killing me. I can get the array 5 slots long with random numbers, unfortunately they're all repeats. when I try getting no repeats I run into infinite loops, exponentially increasing array lengths, and just plain old arrays with 5 numbers randomly generated, but with repeats.
I'm trying to do this with loops, in JS I did it using regular expressions
Here's an example of my code.
Public Class Form1
Dim intRand(0) As Integer
Dim RandomClass As New Random
[Code]....
I'm wondering if anyone else has encountered this in visual studio 2008. I'm writing an asp.net app and when I run through debug it's jumping all over the place. It skips certain lines, at least it appears to, then it jumps to the bottom of the page and repeats the same line a few times then jumps to a separate sub I have in there. The weird thing, besides its behavior, is that it's not grabbing a piece of information that exists in one column but is grabbing another one. So anyone else encountered this? What's the fix.
To give a more detailed example it did this on the last debug. I started the breakpoint at line 40. It went to 43 with no problem then jumps to line 66, an end sub line, it then proceeds to go on to the private sub directly below it. That includes it going over the blank lines that would normally be skipped. It goes through the entire private sub line by line including a catch ex line but it displays no error. After hitting that line it immediately returns to line 46 of the sub that it already passed by the end sub line. It then goes down 2 more lines jumps back to the private sub it just left and repeats the end sub line 3 times, only the b at the end is highlighted when doing this not the whole line.
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].....
Beginning VB 2010, had a project that requires us to create a list box of 25 randomly generated 0s or 1s. Problem is when I put the loop in, it only repeats the same random number, not different one each loop. What am I doing wrong?This is the code I have so far...Code in Question:
'Declare new random object
Dim RandomGenerator As New Random
intRandomNumber = RandomGenerator.Next(0, 2)[code]......
a datacontext defined in a module(domain services ado.net ria)a page having add/delete methods whenever any method is executed, it is found that all the previous actions (NEW RECORD ADDITION and DELETION OF RECORDS) are carried out before the new action is carried out normally
this behaviour is not prominent but "when using break points and inspecting the values of the variables and table object to be added to context, it is clear that all the previous actions take place again. even when the datacotext. savechanges is called, even after that still all actions carried out on the datacontext repeat themseleves, when any new action is to be carried out
I have a report that i'd like to display an Image for each record. But not all records have an image. The problem I have is that the last image is then repeated in the next record.
I would like to know how to have any empty field display a default image.
Code I have in report
Private Sub Detail_Format(Cancel As Integer, FormatCount As Integer)
Me.Image21.Properties("Picture") = Me.PhotoLink
End Sub
Photolink is a textfield and Image21 is an Image.
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."
View 13 RepliesI'm creating a Client Server application which involves theServer running some scripts in clients and getting back results in an automated way. In Server, other than Main thread, i have 2 worker threads, a) one monitoring response from clients and b) the other scheduling next available job to respective client which executes that job. The issue here is ,I want these worker threads to write the status of their work in the UI(which comes under Main Thread). Also i need to write things in worker thread in a Data table and Rich Text Box in Main thread. But, I can't do so, since it has been blocked to access one thread's function or property directly from others. Is there any work around to do this?
View 8 RepliesPreface: I know this is an unusual/improper way to do this. I can do this with a "real" ShowDialog(), background worker/thread, and so on. I am trying to do specifically what I describe here, even if it is ugly. If this is impossible for X reason, I have created a fancy progress dialog for some of our long running operations. I need to have this dialog shown on a new thread while having processing continue on the calling (UI in most cases) thread.
[Code]...
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?