I'm using a background worker to read a XML file and do stuff in a database i get nothing in debugger but when i run it i get this error... how can i find out where and what is wrong? Exception has been thrown by the target of an invocation.
View 6 Repliesread .doc file to textbox with background worker?
View 1 RepliesI've been trying to figure out what is going on with this code, but it looks like I need some help. The issues I'm having is when I click a button that executes my background worker, it freezes and the UI comes back once the listview control is populated.My guess is that some part of my code under the backgroundworker_dowork function is trying to update something on the UI thread causing it to freeze. I just can't figure out what is trying to call the UI.
The user is supposed to click a add server button and enter the server name. The server name will be added to the ListView control. When they click refresh, the background worker is executed which attempts to get the DNS name, IP Addresses, and online/offline status.
Obviously, I'd like to run this code without freezing the UI. Does anyone have any idea on why this might be happening? My guess is because the ListViewItems are passed to the background worker and still have a reference to the control running on the UI thread. Am I right with this statement? If so, how do I change my code to get rid of that reference?
I have a button which on click will save the data into the database and after successful entry of data a messagebox will be displayed.Now,all i want to do is I want to calculate the time of how long does it take between clicking the button and displaying the messagebox.
View 19 RepliesI am trying to interface with excel in a vb.net windows app I am writting. Basically it imports csv files to a data table, adds some additional data from with a oledb datasource, creates a view to sort the data before pushing back in to a datatable and spitting it out to a listview. The list view then allows you to further filter and sort the data (or will do shortly but thats not an issue).From the data in the list there are then 2 options, it will either create individual reports for managers in a excel sheet, which it colour bands based on a total field and then emails out to the managers. This works fine.
The other feature is that it produces a summary report that goes to a central email account. Again it creates an excel workbook, adds 4 work sheets, copies all the data to a master sheet (sheet1), it then starts at the bottom of the master worksheet andcopies the total values from the total row for each employee and copies this value in to the next blank column. (This is basically used so I can determine based on the 3 score bandings which sheet each line should go on. The lines for an employee are madeup of individual leave lines and total line that has the summation of the individual lines for them).
Private Sub Button6_Click(sender As System.Object, e As System.EventArgs) Handles Button6.Click
If btState = False Then
[code].....
Can someone tell me how to get the selected text in the combo as it encountered cross-thread in the following code:
[Code]...
I'm trying to browse for a large file and copy it with a background worker but get the folling error:"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. This exception is only raised if a debugger is attached to the process."
Code:
Private Sub BW_CopyEXE_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BW_CopyEXE.DoWork
Dim fullFilename As String
[code]....
I am having difficulty uploading a file using a background worker class...I've noticed that it is unable to transfer files like "mp3" ".exe" and others...although my application works fine on ".txt" and '.doc" and similar types otherwise it throws the following error following is my code for FTP...Also would like to know that the builtin FTP libraries are capable enough to make a FTP class application with RESUME capability? my files can be huge like 80MB to 100MB. [code]
View 3 Repliesi want background worker to use file copy, how?
View 1 RepliesI 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.
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].....
I want to use the background worker with my XML file i'm reading plus a progress bar....
how can I get the maxvalue of the progress bar? this will depend on how many nodes there are.
I recently upgraded the MS SQL Server installed on my personal computer from 2005 Express to 2008 Express. Problem is when I try to add an SQL database file to a project using VS 2005 I get an error message saying that the version of my database server is not supported, I must have SQL Server 2005 Beta 2 or later installed. I didn't do it yet but I'm pretty sure that when I open the other projects that I included a database file to it, I'm going to get the same error.
My question is it possible to have two SQL Servers installed on my machine? If so, is it a good idea to have two DB servers in the same machine?
I am having a problem with my program that is desinged to read a 3rd party text file database. I posted previosuly about a problem inserting an item in a new row and the column was expectig a different data type. It appears that sometimes the column is being determined to be of decimal value, I dont understand why. the fields contain information such as
Col1
F123456
CLW-12321 etc....
So my column fills with
123456
12321 the letters just get chopped off
So I added MaxScanRows = 0 to my schema file and that took care of the problem
Except now several of my columns that contain Date Values are coming back
9/24/2010 00:00:00
without the setting MaxScanRows = 0
The date returned 9/24/2010
Here is the code for my schema ini file I am creating:
HTML
Dim fs As New FileStream("Schema.ini", FileMode.Create, FileAccess.Write)
Dim writer As New StreamWriter(fs)
[CODE]............
I have been trying different settings hence the dimmed out lines
Here is the code to fill the datatable:
HTML
[CODE].............
I am thinking that without the MaxScanRows = 0 setting the datatype for Col1 is being incorrectly determined
I am not sure what is happening with other columns that contain date values. Apparently If i use MaxScan Rows=0 all columns are being pulled over as string value which creates numerous problems. If I dont use maxscanrows then all columns appear to be correct except Col21 MLSNUM which is being pulled in as a decimal. Can I change that in the schema file?
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].....
im thinking just because an app has been sent ton system tray does not mean its a "back ground worker"
View 1 Repliesmy 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]...
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 RepliesI have a background worker that used to fire its RunworkerCompleted event when its DoWork routine finished querying a database and writing its output to a file. The bg worker was in a class called Query, which was called from another class called Trigger. A new Trigger Class was created for each monitored event. In this class, there was a structure which stored the config of each Trigger. When this event was triggered (set to TRUE) a new query class is created and it is passed the Trigger class. When the database query, file writing was done, the query class and all its rsources were diposed from the RunWorkerCompleted EventRecently I changed the application so that a new trigger class is not created for each monitored event. There is a single instance of the class but new config structure for each event. When a particular event is trigger, jsut the config structure is passed to a new query class and the sma ething is done in the query class. I just noticed now that the RunWorkerCompleted event is not being fired anymore.
View 5 RepliesI have an issue that I can't seem to find a straight answer for anywhere... I have a For loop that sends a file name to a background worker that contains some long running code and I can't find a way for the parent thread to wait for the background worker to finish... Here is the example code:
For 4
BacgroundWorker1.RunWorkerAsync(fileName(i))
Next
[code].....
I have run into this before, When I develop a form to use a background worker to fill tableadapters, the background worker does fine on machines running Vista, but if you run the same thread on an XP machine, the thread gets hung.All the thread is doing is filling a table adapter like this.[code]Why would this run on a Vista machine and not an XP machine?
View 1 RepliesI have created a background worker to go and run a pretty long task that includes creating more threads which will read from a file of urls and crawl each. I tried following it through debugging and found that the background process ends prematurely for no apparent reason.
While Not myreader.EndOfData
Try
currentRow = myreader.ReadFields()
Dim currentField As String
[code]....
This first bit of code is the loop to input from file and this is what the background worker does. The next bit of code is where the background worker creates threads to work all the 'landingPages'. After about 10 threads are created the background worker exits this sub and skips the file input loop and exits the program.
Try
For Each landingPage As String In landingPages
pgbar.Timer1.Stop()
If VisitedPages.Contains(landingPage) Then
[code]....
Also my main thread runs a forms from where this background is called to run but the main thread is supposed to wait for the background process to end unless the user selects another option from the main form.
I've been experimenting with background worker to maintain responsiveness and to allow the UI to update while things are being done in the background.I've been having problems getting the background worker to do anything with form controls.For simplicity lets say I have form1 and form2.The background worker is on form1Initially I couldnt get it to edit controls on form1 but by using [code]However the problem came when I tried to get the same background worker to update controls on form2, in this case a text box. With the above code there is no error but it also does not update the text box.Is there an easy way to give a background worker access to multiple forms.
View 4 Repliesi m trying to kill a background worker in the do work event of the worker i was using
backgroundworker.CancleAsync()
but its shows an error saying tat CancellationPending does not allow
how can i kill a background worker after its work gets completed in its do work event
currently, i have this code: My_BgWorkerB is the Name of my BackGround Worker
If My_BgWorkerB.IsBusy Then
If My_BgWorkerB.WorkerSupportsCancellation Then
My_BgWorkerB.CancelAsync()
[code].....
Is there a way to pause a background worker? What I need to do is pause a background worker when it encounters a file error, wait for a few seconds, and then carry on.
View 2 RepliesI 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 RepliesI have a function it is called ReLoad()
How can i run it as a background worker? so it can run in the background where it does not effect my current running function - basicly so the form will not freeze at all.
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 RepliesI'm new for VB.Net 2008. I am facing some problem about how to make the multiple groups activities running (it might concurrent) based on their own activity's time set? For example: If there is 80 groups and 100++ activities in each group, can i use background worker (create 80 background worker?) to handle this (each background worker handle their group activities.) if in this case (But it will running lag or hang)
View 14 Replies