I am making an application that has a tabbed interface. Each tab uses a UserControl with the controls that I need on it. The user enters some data & clicks a button, which starts a lengthy process. I would like to run that process in a BGW, so that the user can switch to (or open) another tab & process another set of data simultaneously.
View 7 RepliesI am writing an automation program that runs 4 test boxes in line with a handler. Im having a problem with running 4 BGWs(back ground workers). The Program is running fine right now but its not running the way it was designed. What i am trying to do is get all 4 BGWs to run in parallel. what its doing right now is running 3 and then when those three are done running it runs the 4th. the crazy part is its not running 1 2 3 then 4 its running 1 2 4 and then 3. Also its not updating my status windows right either.
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I'm trying to develop an application which searches a sql server database. One particular search entered by the user actually sends seven queries to the database. I've designed it so each of the seven queries is conducted in a seperate backgroundworker, so that they run and return their hits concurrently. When the user enters a search term, a routine (runSearch) is called , which in turn causes each seperate backgroundworker to run.This work fine when the user enters a single search term.I'm now trying to allow the user to enter multiple search terms in a multiline textbox. I iterate through the lines in the textbox and call runsearch for each line. I assumed that the progam would wait for each call to runsearch to complete, before running the next.
I now find out this is not the case. When I call runSearch, the backgroundworkers are set in motion. The next line in the textbox then calls runSearch again, but the backgroundworkers from the previous calling of runSearch are still running. This throws up an error stating that the backgroundworker is still busy and cannot be called.I need a way to test that all of the backgroundworkers have completed before running runsearch again. If one or more of the backgroundworkers are still running
I have an array that is a list of files in a folder, I'm processing the files and renaming them. It takes about 15 minutes to rename them all, this is done daily. I currently have 1 Backgroundworker to handle this and update the UI.
My question is, this: How can I use more than 1 Backgroundworker to use more than 25% of the CPU to do this?
Split the array into 3 parts and call 3 separate workers to do their part?
The code uses dynamically backgroundworkers which all workers great, but with one problem. If you were to look at line:
For Each folderPath In File.ReadAllLines("file path here")
You would see that it loops the text file, and starts background work.
The problem is that it does not list the files in order.
For example were you see "file path here" that were you put the file path.
The text file itself would look something like this:
C: est
C:VB
The program starts listing file from the C:est then goes back to C:VB then back to C:est.
I know the reason why, but I can't stop it. I tried pausing that code inside the loop, but with no luck. How would be able to list the files in order?
vb.net
Private filePaths As New List(Of String)
Private workers As New List(Of BackgroundWorker)
Private Sub GetAllFiles()
For Each folderPath In File.ReadAllLines("file path here")
Dim worker As New BackgroundWorker
[Code] .....
I have a website that has highly granulised access and hence requires many web.config files. The problem is I would like to trim the menu so that only certain users will have access to certain folders. I have enabled trimming and setup roles in the sitemap, however when I access the page the menu is not show, as I am authorized to view the default page which is not in a subfolder. When I type the url of a page in sub folder's I have access.
How should I handle this:
A site map for each web.config file - don't know how this will work Removing the sub web.config file to only use a single one
I have a library of graphical controls used to display values from a remote device. The controls are typically graphical objects such as a digital meter, analog meter, vertical bar, etc. I first create these controls with a value property. The control will display the value property, e.g. the meter needle will move to the position representing the value.
The next thing I do is to create a new control that inherits the previous discussed control. The new control adds properties that allows the value to be set from values retreived through a communication component. My code that does this is 99% the same for all of the controls. Since I already inherit the graphical control, I can not inherit the class that retreives the values from the communication component.
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I need help to implement multiple threads in application.Assume ds.table(0) has 5 and sometime 6 rows rows for i=0 to ds.tables(0).rows.count-1.I have to apply multiple threads, means all five/six rows should start at once using thead and "Process 1" .."Process 4" should also handled by threads.This is hierarchy that I have to apply with threads, how can I do it. It is requested to put piece of code so I can understand better.
View 13 RepliesCan any one explain the usage of interfaces to implement multiple inheritance in VB.NET.
View 6 RepliesI'm currently writing an application that is used to automate a certain task. Currently, it uses the threadpool (using up to 25 threads per the enduser's option). Each thread calls a function which will usually take about two minutes to finish, but it uses a While loop in order to repeat the process. This is my code to start the threads:
Private Sub ProcessAllItems()
For i As Integer = 1 To Me.numThreads.Value Step 1
Threading.ThreadPool.QueueUserWorkItem(New Threading.WaitCallback(AddressOf ProcessItem), i)
Next i
End Sub
The function "ProcessItem()" is the function that contains the While loop. The control "Me.numThreads" is a NumericUpDown control whose max value is set to 25. My question is...is this a good method to follow? To my knowledge after .NET Framework SP1 there is a max of 250 threads/CPU. However I've read the the threadpool is normally used for processing short-lived tasks. Should I be using background workers instead? If so, how could I start up to 25 background workers during runtime depending on the value of "Me.numThreads"?
I am using Visual Basic 2010 Express to develop my windows application.
I am developing an application wherein I need a functionality similar to the outlook email address.
In outlook, we are able to enter multiple email addresses in "To" address box. When typing first few chars of an email, the AutoComplete functionality displays the list of possible email addresses. Either we can select from the list or we can continue typing. As and when we type email addresses, the AutoComplete functionality shows the list of possible email addresses for every email address that we type in the textbox (if anything is there). I am trying to implement this functionality in my application
I found there is a AutoComplete functionality for textbox. below is the code
[Code]....
I know that the AutoComplete is only for one word and not for multiple.
But How to implement the AutoComplete functionality for multiple word in a textbox?
I am making a program that takes pictures of the webbrowser control on a set timer and save them in a picturebox.. I then use backgroundworkers to check the images against others stored in the program. My issue is, the backgroundworkers do not properly check the images against the ones I have stored in the program.Could this be because the images and picturebox are stored on the main thread, and no in a background worker?In other words, I am taking picture from my webbrowser and putting them in my picturebox. Then, I am comparing them with images already in the images. The only problem is, the workers are unable to properly compare the images.
View 6 RepliesI want to build a flip clock for my vb 2008 form.But I cant seem to get it done.So I searched and found a flip clock control for not Vb but silverlight.Here is the link
[URL]
Is there a way I can use this clock in my vb form.
how should i implement networking through vb.net 2008?
View 6 RepliesI am working in vb2008. how to implement the keyword, Me. I see it used in code examples but when I try it, it does not work.
View 3 RepliesI have a custom object that I would like to turn into a Collection that could then be used in a BindingSource. From what I've read, I can Inherit Collection(Of T) where T is my specific object. Then I can Implement IBindingListView. This is all great, but I have no idea how to actually use the IBindingListView Interface. I know I want to be able to sort and filter my collection, so I have the following.
Imports System.ComponentModel
Public Class ChemicalCollection
Inherits Collections.ObjectModel.Collection(Of Chemical)
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As you can see, I haven't really done anything other than let Visual Studio fill in the required properties and methods when I implemented the interface.
i would like to ask if it is possible to implement clickonce like in vb2008 in vb.net 2003?..example:i have a button "Update" in my application running on local machine...if i click it it will check the remote server if there is an update of that app.if yes then download it an change the application on local machine...
View 22 RepliesI want to try and use the new encryption algorithms provided with .NET 3.5. Any links or examples for how to use one of them to encrypt xml content?
As written on msdn site is:
The following algorithms are included:
Advanced Encryption Standard (AES) with key sizes of 128 and 256 bits for encryption.
Secure Hash Algorithm (SHA-256 and SHA-384) for hashing.
Elliptic Curve Digital Signature Algorithm (ECDSA) using curves of 256-bit and 384-bit prime moduli for signing. This algorithm is provided by the ECDsaCng class. It allows you to sign with a private key and verify with a public key.
Elliptic Curve Diffie-Hellman (ECDH) using curves of 256 and 384-bit prime moduli for key exchange/secret agreement. This algorithm is provided by the ECDiffieHellmanCng class.
I am wondering how to implement a barcode reader on vb.net 2008. I haven't started creating a program yet. I have only these simple questions
How to declare Barcode Reader on vb .net?
If I want to scan a product on the barcode reader how to catch the data that is being scanned?
basically add and remove text and selection information from a stack. Result: When using Undo/Redo the selection got messed up, the text moved, sometimes causing lag of epic proportions. I need a way of having complete and smooth undo/redo class for storing all information I would possible need.How to know whether or not to add an undo stack is easy, I just checked if the user clicked in the text or moved using the arrow keys. As soon a previous marking was given for "next text change needs to be backed up", it was backed up. At that point I stored the RTF and selection start/length. What do I have to store of a RichTextbox control to be able to restore it to a previous state, and how can I reset it back to a previous state? See it as having a "RichTextBoxState" class:
Public Class RichTextBoxState
Sub New(ByVal RTB As RichTextBox)
Me.text = RTB.RTF
Me.selectionstart = RTB.SelectionStart
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After restoring it must display the EXACT same thing as when it was saved as a state.
PROJECT TYPE: Windows Forms Application
LANGUAGE: Visual Basic
.NET VERSION: 3.5
IDE: Visual Studio 2008
OPTION STRICT: on
OPTION EXPLICIT: ON
I am developing a parental control application containing a feature that logs a user off of the computer after an administratively set period of time. I do not however want the application to continue counting time against the time limit when the user is not active on the computer. EXAMPLE: Child logs on and is active for an hour then leaves computer for 45 minutes to get dinner. The session timer needs to ignore the 45 minutes of inactivity. I have thought of two ways to accomplish this.
1) Use a SystemEvents.SessionSwith event (to detect the Start Menu > Log Off > SwitchUser action), or
2) Use an event which would detect user inactivity in excess of a set time, e.g. 5 minutes (similar to a screensaver).
Either event would call a method which would simulate a pause feature (as StopWatch and Timer have no pause support that I know of). I believe the 2nd option would prove to be more universally affective as 1) some users do not have Fast User Switching enabled, and 2) users would be required to manually switch users in order to prevent their inactive time from counting against them. My problem arises when I attempt to implement one of these methods. According to the IntelliSense error checking engine, I have absolutely no clue how to do either of these tasks in spite of the research I have conducted on the topic. I would prefer to go with the system idle time approach.
visual basic 2008 express
access 2007 db
I am attempting to fill a form with multiple rows from an access table based off of a parameterized query. My query works fine but I don't want to return one row at a time, I want to return all rows that match my query in multiple text boxes. I know that I can use a datagrid view to accomplish this, but I would prefer the look of a textboxes on a form. I have read through many books and searched the internet forums but think I may just not know what to search for as nothing has worked yet. Can anyone point me in the right direction. So far I have tried setting the text box value to the row().item(), creating a different dataset for each row, and even setting variables for the results of the query to then be passed to the text boxes. Since none of this work, I don't really have any starting code to post. If I could just get a starting point I could work from there, so don't feel the need to code anything for me, just set me in the right direction.
I am upgrading from Visual Studio 2003 to Visual Studio 2008. ow I should upgrade my project.My project is in Visual Basic.Net, and using an Access 2003 Database. I have four datasets, MainDataSet (for the main data tables) LookupDataSet (for lookup tables States, Countries, Colors, etc) OneFormDataSet (data used on only one form) and ReportsDataSet (data used for reports).I have one form "OleDbAdpatForm.vb", that has all the OleDbDataAdpaters for my project. It also has the DataSets and the OleDbConnection.I have public functions that enable me to load the data tables.
I have a LoadTable function when I can pass a column and a value, and the SQL select command is updated with a WHERE or HAVING, so only the requested data is selected. I also can pass the whole "WHERE ..." part of the SQL select command, so I can have multiple parameters in the SELECT command.On my other forms, I have copies of the DataSets, so I can design grids/controls. In the form_Load events, I manually bind the controls to DataSets and tables in located "OleDbAdpatForm.vb", so all forms are using the same data tables, and changes made to data in one form are reflected in data in other forms.The VS 2008's DataSources, BindingSources and TableAdapters seem much easier to use. how I should implement the new data features in my application?
I have been developing an application for quite some time now. I have decided to create an mdi parent form to hold all the windows I have done so far. Is there an easy way to implement the mdi parent/ child associations rather than to go and declare them each one individually.
View 7 Replieshow I can implement my calendar with VB .net express 2008 and MSSQL 2008 Express. How do I get it to work with datasets, binding source etc.If I go to Properties>settings my connection string is:
Data Source=.SQLEXPRESS;AttachDbFilename=|DataDirectory|CalendarDatabase.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True
and I have a table with fields:-
CalendarID
Subject
Location
Purpose
[code]....
I can Add the event to the calendar I have the necessary items on my form linked to my table and I can save them to my table:
Me.Validate()
Me.CalendarTableBindingSource.EndEdit()
Me.TableAdapterManager.UpdateAll(Me.CalendarDatabaseDataSet)
But I cant keep the event displayed on my calendar when I close it and open it again.
I read about CLR in a computer forum. Can anybody give me some example code in CLR (SQL Server 2005)? And does CLR have anything to do with stored procedure in SQL Server 2005?
View 1 RepliesI am trying to implement a BGW and want to report progress to a progress bar for my TextFieldParser program, sometimes if your opening very large files it takes a while and I would like the user to be able to see the progress and have some interaction so they know the program is still running I am a little hung up on what to in the reportprogress
I have:
worker.ReportProgress(0, myReader.ReadFields())
and its not doing anything, I didnt expect it too since ReadFields is an array
parser
Private Sub BackgroundWorker1_DoWork(ByVal sender As Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
Dim worker As System.ComponentModel.BackgroundWorker = DirectCast(sender, System.ComponentModel.BackgroundWorker)
[code]....
I have a Richtextbox and I would Like the user of the program to be able to drag and drog the richtextbox in other specified places in the program.
I have this very basic
Private blnLifting As Boolean = False
Private Sub richTextBox4_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles RichTextBox4.MouseDown
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Firstly its very inaccurate. I want it so the Richtextbox moves with the mouse and not after the mouse. So I want a smooth drag and drog.
So I don't know if this is the wrong code for something that I want perfect like that.
Secondly I dont know if its possible but I would like it so the box can only be dropped in certain area's in my program and if there is a box already occupying that space, It goes back to where it was before.
Dim tempList As New BindingList(Of Advocate)(advocates)
Dim bsource As New BindingSource
bsource.DataSource = tempList
[code].....
I need to write a do until statement. 2 of them actually. 1st one records all of the income and then one that records all of the expense. Then they need to be add to figure a profit or a loss.
View 12 Replies