Background Worker Create Second Thread For Progress Bar?
Apr 6, 2011
I have searched the forum and found several forums related to the backgroundworker thread but have been unsuccessful in finding my answer.My objective is to display an animated gif or progress bar while the program is executing a particular method which can take upwards of several minutes to complete. I cannot get the second thread to run the progress bar while the main progrem is executing the time consuming method. I have created a demo based on another thread and can't seem to get it to create two threads. I was attempting to get the backgroundworker to execute the progress bar while my main code runs on UI thread.
[Code]...
View 10 Replies
ADVERTISEMENT
Jun 7, 2012
my backgroundworker as I just cant get it to work. Basically I have a backgroundworker which does a few tasks but I'm trying to implement a progress bar and a label. I'm going to set the maximum value of the progress bar to 10 and then have it updating as I move with each task, also I'm thinking of a label with the progress bar which will display the progress ie
[Code]...
View 2 Replies
Oct 7, 2009
I'am trying to make app that will show every file in C:[code]Now how can i add progress bar with the background worker.
View 31 Replies
Jun 7, 2012
I have a backgroundworker which does a few tasks but I'm trying to implement a progress bar and a label. I'm going to set the maximum value of the progress bar to 10 and then have it updating as I move with each task, also I'm thinking of a label with the progress bar which will display the progress ie [code]
View 3 Replies
Jun 12, 2011
I am developing a VB application along with MS Access... When I initially load my form I need to put my application to sleep for 3 seconds or else data wont load properly. So for this 3 seconds I would like to show a progress bar displaying a message "Please wait" I tried using background worker but did not find any success... I have gone through many tutorials but for some reason could not accomplish the task.
View 4 Replies
Oct 6, 2011
I just can't see what I am doing wrong here, since I have implemented a progress bar into my background worker it no longer only runs the once (in some cases I have seen the coding within the foor loop run 6 times)
My coding:-
My progress bar max value is set to 10.
BGWorker Do Work Event
[code]....
View 6 Replies
May 28, 2012
I am using a background worker to update a progress bar while inserting data in a database.
Private Sub InsertintoDB_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles InsertintoDB.Click
BackgroundWorker1.RunWorkerAsync()
[Code]....
the error i m getting is exception has been thrown by the target of an invocation.
View 6 Replies
May 9, 2010
I'm creating a program that can run a large audio file (*.wav) in a seperate thread using the background worker, the only problem I'm having is trying to report the progress using a progress bar. When I try to report progress nothing happens. here is the code below:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
BackgroundWorker1.RunWorkerAsync()
[Code].....
View 2 Replies
May 5, 2009
I am using the code below to login to a softphone. However, the login progess is a long process as there are many things that have to be initialized and checks to be made, I have only put a few on here, as it would make the code to long to post.In the code below I am checking if the CancellationPending if the CancelAsync has been called in my cancel button click event, before doing each check. Is this correct? Also if the check fails I also call the CancelAsync and set the e.Cancel to true.
Private Sub bgwProcessLogin_DoWork(ByVal sender As Object, ByVal e As DoWorkEventArgs)
'
' * Perform at test to see if the background worker has been
[code].....
View 1 Replies
Apr 6, 2012
I have a BackgroundWorkerThread which I want to use serially.So some of the code in the UI thread will look like this [code]But of course I can't do the second RunWorkerAsync until the UI thread has seen the RunWorkerCompleted event indicating that the "Sequences" work has been completed (or somehow knows that the "Sequences" work has been completed).So I need some sort of synchronization between the two RunWorkerAsync calls, but whatever I use cannot hang up the UI thread because it has to be able to handle ProgressChanged events.Maybe the RunWorkerCompleted event could make the second call but I really don't like that structure.So how do I delay the second call to RunWorkerAsync (for the "Templates" work) until the background thread has completed the "Sequences" work?
View 6 Replies
Apr 25, 2012
I have a application which processes 1000's datas.. for each processing it needs to update gui and db and many variables in my application. So what i have planned is to use 50~90 background worker with my own algorithm of thread pool, synchronization and thread close.So here is it efficient in terms of memory and performance. just confused what to use.. backgroundworker componenet or standard thread.
View 11 Replies
May 23, 2012
I am using background worker to report progress on the screen. In the Main.vb I have the following
Public Sub report(ByVal sender As System.Object, ByVal e As System.ComponentModel.ProgressChangedEventArgs) Handles bwlistener.ProgressChanged
Dim message As String = e.UserState
logRTB.AppendText(message & vbCrLf)
End Sub
When I call this from Main.vb I use:
bwlistener.ReportProgress(0, "Some status text goes here")
It works great. The problem is when I try to call it from any other module in my project.
When I call it OtherFile.vb:
Main.bwlistener.ReportProgress(0, "Some status text goes here")
It doesn't work... The program doesn't crash. Debug goes through everything but no output is actually shown to the end user.
View 16 Replies
May 30, 2011
I am testing a background workder. I am running the following code for the test.
Private Sub bgwTest_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles bgwTest.DoWork
Dim a As Integer = 0
Do While a < 10 'Infinite loop
ComboBox1.Items.Add(1)
[Code] .....
But this code generates the following error:
"Cross-thread operation not valid: Control 'ComboBox1' accessed from a thread other than the thread it was created on."
View 2 Replies
May 19, 2010
Can someone tell me how to get the selected text in the combo as it encountered cross-thread in the following code:
[Code]...
View 5 Replies
Aug 6, 2010
I'm working on a web application that uses the web browser control to get and set info from my website. The content on the site is pulled from different pages and the data the application stores becomes really huge so i used a background worker to do the work and keep the form responsive. On each loop i call to get the webbrowser's inner html so i can sort through it and grab what i need and it works; but only the first time!? After i call it the first time and try to call it again to update the variables the function hangs and then the console shows me a Thread Abort Exception, The try statement i used to contain it doesn't fire off an exception. When i debug the program and i get to that function, it hangs and then just stops working.
The function that loops:
vb.net
Dim ids As String = GrabIDs()
Dim IDCount As Long = ids.Split(CChar(",")).Length - 1
Do Until IDCount = 0
[Code]....
View 1 Replies
Mar 21, 2011
I use background worker almost daily and works great. Today I came to an instance though where I needed to put my background worker in a separate project then the one I was running because I needed to use this class in two different projects in my solution. When I tested the coding on a winforms form, it works perfectly, handling my coding on the background thread. When I try to reference this class from an external project, all of my coding seems to run just fine, but it does not appear to be doing anything on a background thread as it should be, causing my main window to lockup.
Is there any way around this / what is the best practice for ASYNC calls in an external class.Note I basically created a class that u call start, and an event fires when data is ready, so it's not like my external project is waiting for the method to complete.
Solution ABC has two projects. Project A and Project B. Project A is my WPF application and B is my DLL doing the work. Inside project A I have
Dim SmartCardData as new Solution.B()
SmartCardData.Start()
Project B has a sub
[code]....
View 3 Replies
Dec 11, 2011
how to put this on a background worker without getting cross thread errors??? trying to upload a childform object values to an access db.I don't work in IT,Our company's LAN so slow that it takes around 3~5 seconds trying to update/insert values in access using the code below so putting it on a background worker i think makes the app immediately usable once save/upload's called unless otherwise somebody could suggest a faster way to speed things up.[code]
View 2 Replies
Mar 15, 2010
I was looking for a solution to run a lengthy job (looking for files on the fixed drives) withouth freezing the UI, and saw that using a BackGroundWorker control is the recommended solution.
Problem is, I don't see its ProgressChange event being triggered:
Imports System.IO Imports System.Text.RegularExpressions
Public Class Form1 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Button1.Enabled = False
[Code]...
View 6 Replies
Jun 16, 2011
I have a VB.net project which uses a background worker to do some stuff.
Now I want to expand the project to be able to do multiple stuff :)
A user can enter an URL in a textbox and when the user click on the parse button the program creates a new tabcontrol a outputs some data.
I use a hardcoded background worker for this.
But now I want to run multiple background workers to do this stuff so I can't rely on hard coding the background worker(s).
Is it possible to create background workers dynamically.
how to set this up since I think I need to set up the different methods and variables like:
Private bw As BackgroundWorker = New BackgroundWorker
bw.WorkerReportsProgress = True
bw.WorkerSupportsCancellation = True
[Code]....
I think I need to declare the background workers in some sort of array like variable (list / dictionary)??? Other then that I have no idea how to tackle this.
View 1 Replies
Apr 23, 2009
I have a windows application that need to process som quite time consuming jobs. In my first try i did all processing under
the form thread. The result was bad response and update of the form due to the heavy jobs.To get around the problem with bad response from the form i created a new class "processing" where i put all the data processing. Then i instanciated a background worker where i in the "doWork" sub created a new instance of "processing".The "processing" class creates a timer from system.timer, and the timer drives the processing.On the Timer event Elapsed the timer starts a new thread from the thread pool.
My problem is now when i want to asynchronously close the background worker (with the corresponding function call what ever it is called ...) there is still a timer thread out there that causes exceptions for me.
1. How can i close my background worker and at the same time have the timer to be stopped?
2. Is there a way to synchronize the timer event so that the timer executes from the background worker thread?
3. Is there a better approach for me to adapt?
View 3 Replies
Nov 3, 2011
I am trying to create a new instance of a form if its not allready been created the only problem is is that the instance creation is inside a worker thread.[code]...
View 2 Replies
Jan 14, 2009
Is it possible to create a new instance of the webbrowser class inside of a worker thread?
View 2 Replies
Mar 11, 2009
I have the following code that adds a background worker into a VB.net WPF project:
Imports System
Imports System.ComponentModel
Imports System.ComponentModel.BackgroundWorker
[Code].....
And I get the following error for the DoWork worker event:
Handles clause requires a WithEvents variable defined in the containing type or one of its base types.
It seems like it's missing something in the Event declaration, but can't find it.
View 3 Replies
Feb 17, 2012
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]...
View 2 Replies
May 3, 2012
I am using query from a SQLite database as the AutocompleteCustomSource for a ComboBox. Also, I want to load data in separate thread. My LoadData method works fine when called directly, but it fails when it is called from the BackgroundWorker thread. When it is called from the background thread, it throws a Specified cast is not valid exception on the csearch.AutoCompleteCustomSource.Add(hh("Taj")) line. Below is my code:
Sub LoadData()
Dim connetionString As String
Dim cnn As SQLiteConnection
[Code].....
View 4 Replies
Mar 4, 2009
I'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 Replies
Jul 7, 2010
get the progress bar show the progress of the batchfile running in the background?
View 10 Replies
Nov 12, 2009
Preface: 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]...
View 3 Replies
Jul 15, 2011
I'm writing an application in Visual Basic Express 2008, part of the function being to walk through a folder structure starting from a user specified folder. In my research, I found this thing called a background worker which seemed an appropriate tool to use given the potential size of a target folder structure. I successfully installed the two examples from the library here, and believe I understand the principles involved. Even so, having tried to build this feature into my application, it seems as though it is not working as expected, and, as predicted, debugging a multi-threaded application is a pain in the extremity.
I have this fragment under my "start" button click event -
HomeSource.Enabled = False
HomeCopy.Enabled = False
HomeReport.Enabled = False
[Code].....
View 16 Replies
Jul 18, 2010
im thinking just because an app has been sent ton system tray does not mean its a "back ground worker"
View 1 Replies
