The code below works fine when I put it in form1.vb and change "form1" to "me" but I can't seem go get it to work from my class.
VB
Imports System.Threading
Public Class Class1
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I've looked at the on line doc over and over, and I can't seem to figure out why this won't work. This code runs the thread, and the thread seems to execute the code in the 'threadsafe' sub, however neither the progress bar is updated or the button click performed.
Imports System.Threading
Public Class VisNotify
Inherits Form
[Code].....
I am instantiating a form object in my code behind the dataset just to access some form level variables and to occasionally set a label in the navigator bar. Recently in the b2 Team version of VS2010 there are some strange errors thrown in the immediate window and then I'm tossed out of debug mode and back into the IDE. This code has been operating for some time in this project without this behavior. A team member has just reproduced the behavior in his development machine also.The error that starts the shutdown of the debug instance is this: Control accessed from a thread other than the thread it was created on.
View 4 Repliesim still stuck and i really to get past this and move onto the rest of my program. I'm trying to update a textbox with new text from another class on another thread. I can get this to work no problem on another thread with the same class, and on the same thread in another class. but not on another thread on another class. my code looks like this, when it is run to produces no errors but does not add the test to the text box, what is wierd is i had made some changes to the program to add multiplelines to consolebox.text and then checked console.text from form2 and it produces the values i added but those arent reflected inside in the consolebox for some reason.
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Updating the TextBox from a Thread that calls a function within a Class does not work. I'm trying to get this to work in a DLL (but I tried without as well). The DLL is accepting an Object as an argument[code]....
View 1 RepliesI am having trouble accessing the main thread (my form) when calling thread is running in a class (or module). I have no problem to manipulate a data (in a thread) from a form, the textbox can be updated using delegate and invokerequired but it doesn't seem as easy when the thread that processes a variable is handled by a thread that is running in a class.
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I have a problem with this program
Form1.vb
Imports System.ComponentModel<br/><br/>Public Class Form1
Public Delegate Sub updatePB(ByVal value As Integer)
Private bgworker As BackgroundWorker = New BackgroundWorker
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I'm reading data from a serial port, but the DataReceived event of SerialPort is handled on it's own thread. I want to handle this on the main thread, but simply declaring an event and raising it still results in it being processed on the SerialPort thread. I'm assuming I need to declare a delegate I can call, but I don't see how that would work.
For example, I want to call Sub HandleDataReceived() on the main thread from the DataReceived thread, having HandleDataReceived() run on the main thread. How would I do this?
I have a few forms that have a lot of really intensive updating along with a great deal of user interface (text boxes, button clicking etc) Is it possible to open a separate form as a separate UI thread from the start up form that called it to "show" or open or whatever the new method might be?
View 6 RepliesIs there a way I can run a loop in a seperate thread and increment a progress bar each time the loop iterates? I am trying to run a loop that will take a long time to complete and I dont want the form to be completely crashed out while the loop is running. There are only two ways I can think to solve the problem. The first way is to run the loop on a timer. This is extremely slow. The other way is to use a thread.
View 1 RepliesI just finished up my space invaders movement and with all the other timers running it really bogs it down. So I think the best solution would be to make the timers run on separate threads. I know roughly how to do this from a old example I read a long time ago. So I just need a simple sample code to refresh my memory please. Maybe something with message boxes or something to demonstrate the process.
View 1 RepliesExample:
Two files - TestClass.vb, myForm.vb
TestClass.vb looks as follows:
Imports System.Threading
Public Class TestClass
Private myClassThread As New Thread(AddressOf StartMyClassThread)
[code]....
The result:Application runs, no errors or exceptions.Displayed is the listbox and the Start button.I press the start button and a msgbox says "Not Invoked" as expected and upon clicking OK to that msgbox "Start Button Pressed" is added to the Output listbox control.Immediately following that the msgbox pops up again and says "Not Invoked". I was expecting "Invoked" as a separate thread is trying to use the Output listbox control.Of course this results in the Output.Items.Add being attempted which results in no visible result as the thread is not allowed to directly update the UI control.
how can i allow a progressbar to be changed on a seperate thread? my code keeps saying that i cannot access it because it was created on a seperate thread:
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If it is not worth it, it is not fun - you say programmers are boring but i say they are worth it.
So, I'm having troubles implementing a separate thread. This is because I have a simple class, and in it I start a new thread. So, as it is not any form, I haven't found any way to make it call the function in the UI Thread.
So, I cannot use the Invoke method. Is there any way to call a function from another thread?
I would like my application to do something (in one form) and while form is doing that i would like to show another form to the user. Code is:
Private Sub blaa()
Dim a As New Working() 'working is another form
a.Show()
'Do some stuff
a.Close()
End Sub
But when i make new form i find it is on the same (main thread) and therefore new form also frozes. How to make new form on separate thread?
I've made an application which goes through a long procedure when a button is clicked. I don't want the user to think the program has frozen, so I'd like to add a marquee progress bar just to show that it's still running. However, if I simply add the progress bar and make it visible when the button is clicked, the bar will appear but freeze and wait for the procedure to finish before it starts scrolling.
I know this is due to both the procedure and the progress bar running on the same thread, but the tutorials I've seen on getting a process to run on another thread seem confusing. What is the simple way to make a progress bar run on a separate thread?
when trying to run a function in a separate thread, my reason for trying this is because since the application is only run on one thread, the GUI hangs when the function is called.[code]In this code, the Print screen Button is pressed and the function HookCallBack is called.The problem is that the function has variables that need to be passed and returned, and while searching, i found a website that had an answer for this, and it required the function to be put in a class, and then it could be run on a separate thread while still passing all the variables needed.url...But the code cannot be placed in a class without giving errors and it seems to me like i did something wrong. The code is meant to be used in a form and not a class.My question is, how would i go about running the HookCallBack Function in a Separate thread?
View 5 RepliesHere's the problem I am trying to solve. My program can export a file as a pdf. and other formats. I can open the file using process.start. My file doesnt have a good name so I am using a GUID as a name.
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I'm working on a checksum tool, which loads all the files in a specific folder to a listview then, calculates the hash value of each file and save it to a text file.Ok, everything is working properly except for the calculation, when I start it on a separate the my UI freezes.[code]...
View 5 RepliesA BackgroundWorker thread can pass data to the primary thread. It does it via the RunWorkerCompleted and ProgressChanged events, which I believe run in the primary thread. I would like to encapsulate the BackgroundWorker control in a class so that I can instantiate it more than once. But I don't know how the BGW can then communicate with the primary thread. If the BGW control is within a class, it does not have access to the properties outside the class. In that case, how can the BGW pass data to the thread that instantiated it?
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For some reason, the following code is causing me some issues. This code pulls lockout status data from AD and contains the data within a datatable. An event is raised from the threaded procedure to add the data to a listview control. For some reason one row of data gets added to the listview control and when you run the procedure gain, 2 rows of the same data gets added, and then 3 rows, etc.
This code calls the procedure "CallGetUserLockout"
GetLockoutStatusToolStripMenuItem.DropDownItems.Add("For Current User - " & User, Nothing, AddressOf CallGetUserLockout)
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Currently I'm creating a task that runs a hardware i/o loop for the duration of my program.i.e. it's a task that's created at the program's start and runs a loop that is only broken at the programs termination. Each loop cycle communicates via ethernet to hardware.depending on time outs each cycle takes 30-300 msec)I've noticed that if the loop runs with out any break that the program really slows down... to counter act that I placed a thread.sleep(x) in the loop
View 6 RepliesI have created a form in which i am loading thousand of records. so i want to display a progress bar.Actually i am moving from MDI main meny to some other form so when i click that menu item i want to progress bar till my total records are not loaded.
View 3 RepliesAfter many searches i end up using this class for global keyboard hooking. Link: Global Hook post [code]My app is performing operations that take some seconds to complete (ftp upload small files on interval), and during this time the hook lovks the keyboard. This i dont want of course..I cant jump to Async FtpWebRequest right now because it needs many changes, so i thought that the solution would be to make the hoook live in another thread.A proposal is to move my time - consuming operations (upload) to another thread.Upon doing this i am facing other problems. Because the time consuming task (upload) is in a timer i would have to rewrite a big portion in order to synchronize the file->save with the file->upload and i dont mind the app locking for 3-4 secs. what i do mind is to loose the kayboard for 3-4 secs.
View 2 Repliesmy application receive data from serial port and store it in ConcurrentQuequeFor not lost any data from serial port I need to plot it in a separate theadin SummaryForm Load = set all parameter of ZedGraphPulsante Start = Open serial Port and start Thead
View 5 Replieshow to access the main ui's labels from a delegate method?
View 7 RepliesIm working with and trying to run an infinite loop on a new thread which at some point takes action (e.g. make changes to Viewport3D). But no matter what I use:
- BeginInvoke
- Background Worker
- Timer
I run into problems. My porblems are:
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I am doing all this in WPF.
How can I run the loop in the background and get it to affect the Viewport3D controls content without throwing an error or freezing up the application? A Viewpoirt3D is a control in WPF.
I have a program that runs for some time and I would like to update the user on its progress. The rest of the GUI is updated using Delegates and Invokes and such (Java is Soooo much cleaner in this regard - everything is thread safe!!), but there is no invoke method for the progress bar. How can I use a delegate to update the progress bar when there is no invoke to invoke!!
View 1 RepliesI am using vb.net 2005In my form load procedure I am starting a background thread.The thread is declared as public.
Public
threadMonitorWMI As System.Threading.Thread
And started in form_load
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I have a really simple form with a button that fires a Sub I created which gathers data from ActiveDirectory and adds it to an Excel Sheet. The problem is, when I click this button the whole form hangs. So I figured the operation that gathers the data and adding it to the Excel sheet should be run in it's own thread, so that the form won't hang. Possibly it would be great to add a progressbar as well. The progressbar however is located at the Main userform that starts up once the projects is run.
I've got one MainForm.vb and one CodeFile.vb. I want most of the code in the CodeFile.vb so it's tidier.
MainForm.vb
Imports User_edit.CodeFile
Imports System.ComponentModel
Public Class MainForm
Private Sub btnImportData_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnImportData.Click
[Code] .....
Notice the ExportFromAD Sub I've got in the CodeFile.vb. This is what is actually doing the work. In the For each loop that adds data to the Excel is where I've put the MainForm.MyBackgroundWorker.ReportProgress(i * 10). Problem is, it doesn't actually update the label on the form. Which I find pretty weird because the form isn't really hanging or anything. Is it trying to access a different thread or something? Meaning, the form is run on it's own thread which can't be accessed from my second thread?