So this is really starting to stress me out. I have a thread that basically scans a device using a .net object distributed by the company that makes the device. The thread is basically an infinite loop that goes like this:
[Code]...
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
[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
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 want check a text file each minute for a change. How Can I start this procedure each minute?
View 4 RepliesI'm trying to calculate the total number of minute that pass 8.00am .. there are few record that the time are greater than 8.00 am which is : 08:15:00, 08:07:00, 08:05:14, 09:01:01 15 + 7 + 5 +61 =88 minute so I should get 88 minute then show it on label1.text
Dim dc As New DataClassesDataContext
Dim q = (From p In dc.times
Where p.name.Equals("Nick") And p.time > New TimeSpan(8, 0, 0) _
[code]....
I'm having some trouble trying to get a 10 minute timer to work. Basically the user can choose to complete the question timed or not, if they select timed I want the program to display the time as it counts down and display a message once the time it up.
This is my code so far:
Private Sub btnstartassess_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnstartassess.Click
If rbtntimed.Checked = True Then
[Code].....
I have a timer that runs ever minute, but the timer waits the full minute to run the code in the timer. Can I have the timer run the code when it first starts, then update every minute?
View 3 RepliesI've built an desktop application to go with my website and I am trying to put an iframe on to my application and have it refresh every 1 minute, the reason is I have a few presentation videos and after being on the page for 1 minute I want the iframe to refresh to a new video which would be dynamically generated at random from the database.
View 18 RepliesI have a program. Every now and then (every 1-2 hours) i would like this program to run, do its stuff, and then close. I don't want it running all the time, just for a minute or two before closing. Is there some kind of windows thing that will tell my program to run or must i make a 2nd program to do this for me? (If i have to make another program, then how can I keep it completely invisible?)
View 3 RepliesThe program runs off a timer that execute the cndstart button every 15 minutes but then it throws out a variable not defined error "oleasMailItem" but if I take the timer out and click the cmdstart button then the application runs fine without errors and I don't know where I went wrong if I add the timer
[code]
Option Explicit
Dim MinCount As Integer
Private Sub cmdstart_Click()
[Code]...
How can I check every minute if a process is running: (notepad.exe)
View 9 Repliesi have the decimal 0,22727272727272727272727272727273 and i like to convert it to hour, minute, second, the zero represent hour.
View 6 Replieshow to extract data from this web page url...Its mainly the Ip address and port but i have no idea in where to start. I know to start out with this Dim elements As HtmlElement Collection = Me.botBrowser.Document.All.but i dont know how i would transverse the source code to find the ip address and port.Also like if i just wanted to first one on the page each time the page refreshed how would i do this also
View 7 RepliesOkay, I've been at this ALL DAY no one's advice has helped so I'm zipping up the simplest version of my problem and attaching it a silver dollar for anyone who wants a quick and (seemingly) easy problem. What it is:
frm1 loads with a button to start frm2(and populate a datagridview).I'm trying to save its data in the module in the example but it might not be necessary.Then another button closes/hides form2 and you can push a button on form 1 to TRY TO get the frm2.datagridview1.item(0,0).value.I can't do any more tonight.
[code] As my program above, i set the time interval to every 5 minute which it will do the function. However, after 5 minites it does not affect any thing in my program, is that my coding wrong? or I had miss something?
View 7 RepliesI need scheduler for my program that runs something every X day, hour or minute. And user can set that how long to wait until it run again.
View 11 RepliesI have a timer, and I want it to stop after 1 minute, and to have a message box pop up saying that it's done.
View 11 RepliesI am having a mental block on how to work out a 15 minute timer that is shown on a label and counts down so that the user can watch it. I can do it just fine in seconds but I need to put it into the format of 15:00 and then have it count down the seconds and the the minutes when ever it drops 60 seconds. I found a few articles on using the dateNow syntax but that seems like it would only be good for adding time not subtracting it. Also I know I can set up a button to start and stop the timer but is it possible to use the space bar as the start/stop button?
View 5 RepliesI am working on code for a countdown timer, where 2 labels (Minutes label = label6 and Seconds label = label7). I have tried for a long time to try and get this to work, and it has to be "Hours:Minute" format. I will add below the awful start I have made
If Label7.Text = "1" Then
Label6.Text = (Label6.Text) - Val(1)
ElseIf Label7.Text = "1" Then
Label7.Text = "59"
[Code] .....
There is lots of bugs, such as the last minute is cut out, and it is just buggy, the user must be able to select a time/duration for the timer to work, and also this must be able to change every time the time reaches 00:00.
I would lik a timer of 1 minute in one of my forms, and when that timer reaches zero, it would automaticly resume to the next form
View 10 Replies