I am using a background worker's work method to create a new form and show it.
But it throws this error
System.Threading.ThreadStateException was unhandled by user code
Message="Current thread must be set to single thread apartment (STA) mode before OLE calls can be made. Ensure that your Main function has STAThreadAttribute marked on it."
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in my button click event i ececure
If BackgroundWorker4.IsBusy Then
BackgroundWorker1.CancelAsync()
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after proceess completed if press the button again.i got the following error msg
This BackgroundWorker is currently busy and cannot run multiple tasks concurrently.
Private Sub Timer3_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer3.Tick
Timer3.Interval = (ComboBox2.Text)
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I was wondering if or how I could error proof a combobox.example: "If combobox1.text = (something that i dont have added into the combobox for the user already) then msgbox "Error: Use the items already in there" "but i didnt want to go through everything lieif combobox1.text = 1 then errorif it = 2 then error, if it = A then error.
View 2 RepliesI am using BackgroundWorker to connect asynchronously to a database. Private Sub frmMain_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
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While my connection is being opened, I have a "Loading" animation show in a lblCalibration. Once it's connected, the animation stops successfully and shows the calibrated record that I am fetching from my db.
However, if there is an error while connecting to my db for any reason, it does not work. My app freezes. The reason is because I am trying to make a cross-thread call while trying to Catch the error in the DoWork event.[URL]..
but still cannot seem to make any progress. Does anyone have any tips or advice on how to properly catch the error and still run BackgroundWorker?
Trying to build a small array to fill a combobox, when I type my code I have no errors in the error list, but when i go to compile/run/debug I get:
Dim arrayDC(2, 2) As Array
Public Sub buildarrayDC()
Me.arrayDC.SetValue("Item1", 0, 0) InvalidCastException was unhandled
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i use this to populate my datagridview:
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to replace this default dialog please handle dataerror event and the combos value then changes to the id of the job i select
I have a search function in my program that uses a background worker in order to get the results. The Progress changed event is used to update the listview with the new item.[code]
View 2 RepliesI cannot figure this one out.. I have a background worker that will perform a task streaming data from some webpages. this data is then passed back and displayed in a gridview. It has been working fine.
I've recently implemented a listbox, which its values will be passed into the function that the background worker will perform as parameters, originally i had taken a single value from a textbox.
Now, I thought maybe it had something to do with the listbox, so I used a static value, just a simple String, as the parameter, and again, I get the TargetInvocationException was unhandled.. There's no difference in how I perform the task I'm trying to have the backgroundworker complete, the only difference is where it exists in my if condition statement:
Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles ScrapeSites.DoWork
Dim results As ArrayList
Dim worker As System.ComponentModel.BackgroundWorker = DirectCast(sender, System.ComponentModel.BackgroundWorker)
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I have a project in VSTO/VB using a BackgroundWorker that works fine. It is a form that calls for a web page of information. The web page can take a while, so I have the form calling with the BackgroundWorker.I then have an Excel Addin project that has added the BackgroundWorker project. When I call up the form from the Excel Addin project and use the BackgroundWorker to request the web page, it grabs the web page ok. But the work done upon completion, during the BackgroundWorker1_RunWorkerCompleted method, is resulting in an error message:
View 2 Replies[Code] This is run from inside a backgroundworker. It throws an error, Cross-thread operation not valid: Control 'pbUpload' accessed from a thread other than the thread it was created on. I have read and read and searched and basically come to the conclusion I am going to have to invoke the command but this is new area for me.
View 5 RepliesI have a backgroundworker that is downloading data from different webpages and process them to a datagridview.I get the Cross-thread operation not valid error on the first For loop.
Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
dim i as integer
tot = (numPostnrTo.Value - numPostnrFrom.Value) / 10
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Let's say a custom exception is thrown in the DoWork event for a backgroundworker. How do I pass the custom exception to the backgroundworker so that it ends up being the e.Error in the RunWorkedCompletedEventArgs?
View 1 RepliesI was messing around with the listview Control first,, And when i got it working i thought what's this backgroundworker thing,,so i read up on what info MS had on the MSDN page..and slapped it in here..and i thought i had it working ok until i tried to move my project application to the side to reply to a instant message i got..and then i noticed that it froze up .and looked like it was using alot of system resources,But wait let me back up just a bit.originally i was trying it with a fairly small number of items, and then i seen on here where someone had posted a rather large index for testing his app with,,and while trying to load that list that's when the issue was noticed i don't really plan on loading a list as big as that test index was but, I would still like to know why the program did what it did using the code below.I'm not really asking for it to be too altered, i kinda like all the controls i have in it the moment,, and the way it loaded as well.
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I am getting a list of computer on my network. I want to run this code in the background but I keep getting an error. How do I delegate the TreeView.Error :The action being performed on this control is being called from the wrong thread
Dim rip As Integer
For rip = 1 To 254
Application.DoEvents()
If My.Computer.Network.Ping(IPArray(0) & "." & IPArray(1) & "." & IPArray(2) & "." & rip, 60) Then
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I'm trying to do some calculations with the backgroundworker and display a window with a loading animation on it. The calculation is working but the loading animation isnt moving.MeasurePolygons is the Sub that does the calculations and updates the variables to hold the values of the calculations which works fine. Its just the loading screen. It pops up as it should but just doesnt animate
Private Sub ClickEvent()
BackgroundWorker1.RunWorkerAsync()
If Window1.frmLoading Is Nothing Then
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I have to write a program that retrieve record from database, but everytime the screen will look like getting hang when getting large row record.I using the backgroundworker to prevent screen hang when retrieving record from database but why my progress not working when in progress? It only will show when the transaction done..
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I have some classes right now that I have that I reuse for Client/Server programming. I'm using Thread in these classes though for monitoring for things being written to the network streams and stuff like that. I'm just not sure if I should be using the background worker class instead. I'm also using TCPClient and Listener classes, should I be using sockets directly? I guess it would all depend on the flexibility I would need in a given application's specs.
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I am having trouble with getting a delegate to work properly.Here's my
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i list all sub-directories in backgroundworker :
Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
If My.Computer.FileSystem.DirectoryExists(My.Settings.path) = True Then
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I am trying to run a database query in a BGW to fill a DataGridView with the data that is returned by the query. The code I came up with works in that it executes the query & fills the DGV but it totally freezes the form & all controls on the form. Successive clicking on the form or any controls causes "Not Responding" to show in the title bar & I have to terminate the program from the IDE. If I run the query in a regular subroutine it works fine. Can somebody please review my code to see where I might be going astray? I've never used a BGW before so maybe I'm doing it all wrong.
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I am using .net 2008. I have placed a ComboBox on the form and I do not have an additem.
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I don't have muc experience with backgroundworkers, but this is basicalmly what I want it to do:
- Copy files from a list
- Add Succes/Fail to a listview
- Report Progress
Private Sub BackgroundWorker2_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker2.DoWork
'2 groups
Dim Succes As New ListViewGroup("Succes")
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It doesn't copy the files, nor does it report progress.
How to make backgroundworker work on the login module??My form have progressbar with Marquee style...
Private Sub btnLogin_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLogin.Click
lblProgress.Visible = True
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I'm running some tasks on a BackgroundWorker thread and needed to display the current tasks in a label.Before adding the label, the tasks were completing just fine and the UI was responsive.Once I added the labels, the UI has become unresponsive. The issue, I believe, is the Invoke property.I've declared all my tasks, including the updating, in a sub and am getting the Invoke property of the label each time, in order to set the information.The following is an example of what I'm doing:
VB.NET
Private Sub Test()If lblTask.InvokeRequired = True Then Dim mi As New MethodInvoker(AddressOf Test) lblTask.Invoke(mi)
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Ive read through tons of forums, but my Backgroundworker1.CancelAsync still isn't working.I have Form1 that shows Form3(see code).when btn_submit is clicked on Form3 it runs the backgroundworker, copies a file from one place to another, and shows the progress in the progressbar.Form3 contains: lbl_message, btn_submit, btn_cancel, ProgressBar1, BackgroundWorker1 (with Workersupportcancelation = true.)When i click on the btn_cancel the copy continues, so i assume the backgroundworker has not stopped.[code]
View 2 RepliesOf course, it's nice enough to unfreeze itself when the task is completed. I have must at looked at this code for 2 hours, and still can't find the bug.
Imports System.Threading
Public Class Form1
Dim PathAmount As Integer = 0
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I am trying to use the background worker to keep my application responsive during the calculations it does. All I need is one to calculate and the other to count time which I use a timer for. But when I try to use a progress bar as well as I want to see the progress it gives me an InvalidOperationException: Cross-thread operation not valid: Control 'ProgressBar1' accessed from a thread other than the thread it was created on. I need this to work, how could I use a component from outside the background worker? This is the background worker bit:
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I am trying to make a graphics program with mousewheel-controlled zooming using GDI+. My plan is to provide rapid feedback, such as a low resolution render or even just a bounding rectangle, followed by a full resolution render as soon as possible afterwards. It seems logical to me to try a BackgroundWorker for the latter task. This is my first attempt to use one of these, or any other way of multithreading for that matter. Mousewheel events can follow one another much more quickly than I can render to the screen. That means I need to kill any rendering process that is already running and start a new one with the latest value of the zoom scaling factor.[code]The above class coexists with a DrawingSurface class, a UserControl which listens for the ProvideFeedback and ScaledImageReady events and paints the image accordingly. It also raises mouse/keyboard events for the zoom and other tools to deal with. My problem arises in the DO loop waiting for Cancellation to finish. The zooming routine works for one or maybe half a dozen renders, depending on the image size, but then it hangs in that loop and never comes out.
View 2 RepliesI have created a application that creates a windows schedule task that connects to a FTP server and uploads/synchronize selected files and folders from your computer. After the user has selected all needed information and click continue, a form with a progressbar (Marquee) should appear. The application will then perform different tasks needed for the schedule to be completed. When all needed tasks are finished i want the progressForm to close and the main form will show you a summary of the newly created task.
I run the tasks in the main thread and assign a backgroundworker for the porgressFrom. i have have also tried to run the taks in a backgroundworker.
Button Continue Click Event.
Private Sub btn_Continue_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_Continue.Click
Try
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