BackgroundWorker - Calling Procedures From DoWork
Aug 30, 2009
As I teach myself VB, I'm working on using the backgroundworker. Mostly I'd like to use it to update a progress bar. But here the problem I'm running into...
When I use it like this:
Private Sub TestWorker_DoWork(ByVal sender As Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles TestWorker.DoWork
Dim ListText As String
For Value As Integer = 0 To 100
If TestWorker.CancellationPending Then
[Code] .....
Where GetPlayerNames() is the Sub that really contains a majority of my code, which uses a class library I wrote, and calls other functions, etc. But this just causes the backgroundworker to skip right to the RunWorkerCompleted and executes no code. It seems to me you should be able to call procedures from the DoWork and then pass updates back via the ProgressChanged event. I can't image you need to consolidate all your code into the DoWork.
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Jan 21, 2010
I am trying to do the following process in the method of BackgroundWorker.DoWork()
Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
For x = 0 To 100
[Code].....
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Sep 22, 2010
I have seen others with a similar issue but not quite what I was looking for. In the backgrounderworker class dowork event I create an instance of a new class and call one of it's function. Previously, I had this code in a windows.form.timer tick event and would pass a delegate in as one of the parameters which would allow the function and other functions it calls within the class to call a method on the form to update a datagrid on the GUI. Is there a way to do this within the dowork event? I need this because the function I call from dowork calls other functions and I want each of those functions to log information in the GUI datagrid.
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Jun 13, 2011
have a formthat hasa BackgroundWorker,on the do_work event i exe an SP:
Dim result As IAsyncResult = cmd.BeginExecuteNonQuery()
Dim rowCount As Integer = cmd.EndExecuteNonQuery(result)
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Oct 6, 2010
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?
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Nov 4, 2011
I have a Custom.ascx file that is used on a number of pages. Custom.ascx contains a couple of controls and a button called cmdCustomPageButton. When the user click on cmdCustomPageButton, cmdCustomPageButton executes a Protected Sub that gets some data from a database.
Page1.aspx that is using Custom.ascx has its own set of controls and procedures that it executes. It contains a button called cmdPage1Button and a procedure called RetriveData that is being called by other procedures as well within Page1.aspx. When cmdPage1Button is clicked it calls RetriveData. RetriveData is only applicable to Page1.aspx. Page2.aspx and Page3.aspx both has a procedure similar to RetriveData but is only relevant to its own page.
Try to explain using code:
Custom.ascx
Public Class Custom
Protected Sub cmdCustomPageButton_Click(Byval sender as Object, ByVal e as EventArgs) Handels
[CODE]..............
The question. How do I call the different RetriveData procedure form the relevant pages being it Page1, Page2 or Page3 when cmdCustomPageButton is clicked ?
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Jul 10, 2009
calling stored procedures using ADO.NET. We have an application developed, which uses SQL Sever as backend and Visual foxpro as front end. In this application every thing is done by database only. That is all insert, update, delete operations are done by SQL Server only. So we have to provide some input and output paramaters to stored procedures. Some time these procedure carry out insert, update, delete operations as well as return some data in the form of tables.
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Dec 4, 2009
I would like to know the pros and cons of calling procedures with Call Keyword and without Call in VB.NET?
Private Sub ProOne()
// Code Are Here
End Sub[code].....
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Dec 14, 2009
in my button click event i ececure
If BackgroundWorker4.IsBusy Then
BackgroundWorker1.CancelAsync()
End If[code]....
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.
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Oct 26, 2009
I am trying to execute the following line of code within the DoWork event of a BackgroundWorker object: [code]
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Nov 9, 2010
I am trying to get a progress bar to update on my Form while waiting for a process to complete but could not get my progressbar control to update.
First of, I have tried to fix the problem for a day and a half now looking at various codes and examples in the forums but I'm afraid I probably do not have the necessary VB skills yet to troubleshoot my own code. I believe I will be able to eventually fix this after I am done with my VB book
I've attached the relevant part of my code below and the problem is that I can see my DoWork event firing off and changing the time and percentage that I want to pass on to ReportProgress() and the ProgressChanged handler. However, the ProgressChanged handler is not raised until after my Do Loop is done.
Imports System.ComponentModel
.
.
.
Public Class Form1
Private WithEvents TestWorker As System.ComponentModel.BackgroundWorker
[Code]....
Again, I can see the ProgressChange fire but only after my work (diagnostics) is complete so my progress bar is either 0% or 100%. In Dowork, I can verify that the progtimepercentage variable is indeed changing and ReportProgress is called but ProgressChanged is not being raised until after the job I wanted is done.
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May 6, 2009
In my DoWork() function I register with our sip server. Then I have to wait for a response back. However, the response I get is received in another event. However, before I am able to check the flag in the DoWork() the DoWork() has all ready finished and the response comes after.
I am trying to find a way to wait in the DoWork() until I get a response in the Diagnotic event. I have a global flag that is set in that event that I have to check in the DoWork().I was thinking of maybe blocking in the DoWork() until the other event is finished. Maybe using a join.
' Do work in background worker
'Will return less than 8 if there are no error message from the library
If (Not Me.bgwProcessLogin.CancellationPending) Then
' Register and wait for response
[code]....
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Mar 26, 2010
How would you create and use a delegate to update the text of the main form from the DoWork event of a backgoundWorker?
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Apr 2, 2012
i'm in the need to start a backgroundworker inside another one.Now...The first one BGW starts a for cycle, and inside this one there is the second BGW that has to upload an image to a server.The trouble is that, the progress event and the complete event of the internal BGW are never called.
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Nov 16, 2009
I' ve got a short question concerning BackgroundWorker.Is it possible to have the main code for the BGW in one class and the long process for the BGW (DoWork) in another class or module?
I couldn't find anything helpful on the internet.Here is my code - DoWork in a separate class doesn't work:
[Code]...
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May 10, 2009
I'm trying to learn how to use procedures?
Public Function mgboc(ByVal mboc1 As String, ByVal mboc2 As String) As String
Return mboc1, mboc2
End Function
But it doesnt work. I want it to "return" the parameters, but it won't even compile.
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Jan 12, 2010
Why we use CLR procedures. Is there any significance of CLR Procedures or any example where CLR Procedure is the only solution?
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Jan 20, 2012
How can i call a procedure to calculate the cost of the suv and compact car mileage twice with that same procedure? Thats the only part i cant figure out with this function/procedure stuff. Also am i doing the procedures right?
Quote:
'Developer: John Nelson
'Date: Janurary 18 , 2012
'App Name: Compare Fuel Cost
[code]....
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Feb 28, 2011
i have made some stored procedures for the first time and now i want to use them in vb.net code
'"Insert Procedure"
Sub InsertSettingz()
'Store the settings for the reports
[code]......
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Nov 23, 2011
I have a function in my program that adjust sales for multiple days. Sometimes it needs to adjust up to 3 months and the tasks takes a while so I decided to split up the work between multiple threads. The way I have it working is say I need to adjust 3 months. I have the first thread adjust sales for the 1st month, the second thread adjust sales for the 2nd month and finally a third thread that will adjust sales for the 3rd month. Since all three threads are performing the same tasks except for different date range they use the same procedures. Within those procedures I make a call to the database to extract the sales for the given month. At some point it seems like the threads start to use the same SQL Data Objects because I am receiving the below error."There is already an open DataReader associated with this Command which must be closed first."Below is the first procedure that is ran by each thread up to the line where it errors out.
Private Sub Process_Adjustments(ByRef objAdjustBillCodeThreadParameters As clsAdjustBillCodeThreadParameters)
Dim cmd As SqlClient.SqlCommand
[code]....
So all three threads call this subroutine and the first thread does the data fill with no issues and then sometimes even the second thread does the data fill with no issue but then the third thread crashes and produces the above error. It seems as though the threads are sharing the same SQL Objects when all objects are local to the sub and I always thought each thread had it's own memory to work with. So I thought each thread would call the sub create it's own objects in memory, but that does not seem like what it's doing. I have other multithreading processes in my application that work perfectly fine, this is the first time I am attempting to multithread in this manner where I am using the same procedure within multiple threads.
Just thought of something that I might be doing wrong. The subroutine in question is in the same class where the threads are created. Should the subroutine be in it's own class, and therefore each instantiation of that class?
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Feb 3, 2010
I created a subprocedure to change the background color of the selected matching labels in this concetration game. Now I want to change it back to silver when all the labels are selected I tried all the insertion points I could think of for a EndGame function but none have worked. I'm thinking I'm barking up the wrong tree.[code]
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Feb 18, 2010
I've lived in the VB6 world for the last 15 years and am only now starting to learn .NET. I've got a long way to go, but I am hung up on a fundamental issue about collections.I live and die by collections in VB6; I use them for just about everything I do.So I am very used to having the abilities that the intrinsic VB6 Collection has.Things like adding items with keys, referencing items by key or index, having the "Add" method return an instance of the object, being able to add custom procedures to the collection, having it strongly typed, etc.But all of the collection information I have read about in .NET doesn't really do all of this.(I am starting out in VB.NET, with the possibility of moving to C# at a later time, so i am trying to stay away from the Microsoft.VisualBasic namespace.)
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Jul 25, 2009
Some question about Ado.net and SQL Server stored procedures. We have a stored procedure in SQL Server as described below
Procedure dob.PendingCalls
@UsID As Char(10), @Sts As Integer OUTPUT , @Msg As VarChar(100) OUTPUT
AS
Begin
[code]....
we are using vb.net in visual studio 2003. Now if ExecuteNonQuery is used then we do not get rows. If ExecuteReader is used then we get rows [ with forward-only access which is of no use to us] but we cannot get output parameters values returned by stored procedure?
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Jun 3, 2011
Im currently working on a car service program on Visual Basic. The user simply selects some radio buttons, enters a couple of values and at the end the lablels are SubTotal, VAT and Total. Can anyone tell me how I calculate the VAT, the VAT rate I need to use is 20%. I currently have an appropiate answer for the Sub Total. I know I need to multiply the SubTotal amount by 0.2 but how do I do this using Procedures and Functions?
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Dec 29, 2011
I have a block of related sub routines I would like to "group" together within class to make navigating a littel easier. When I say group, I mean achieve the same functionality of being able collapse and expand a block of code as would with single procedure or class. Two alternative ways I can think to accomplish this is either use a partial class for those procedures or use namespace. I just wanted to see if VS for VB.Net had another way to be able group and collapse blocks of procedures.
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Jun 11, 2012
Am looking for a Currency Text Box control that will accept numeric key input and display entry as Currency according to Users Regional Settings.
Additionally, when an assignment is made such as Currencycontrol.text= 123.45 + 500 , user will see value displayed as $623.45 or formatted to regional specifications.
I do need a control rather than formatting procedures since my form could have 24 or more currency fields.
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Nov 30, 2011
If I write many subs and functions in my code, the tools on the interface will stop responding to some of the subs and functions. What can I do about that?
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Jul 26, 2010
The code below is right to execute more store procedures?
Dim mySQLCommand1 As New SqlCommand("sTruncate", myConn)
Dim mySQLCommand2 As New SqlCommand("sAddress", myConn)
Dim mySQLCommand3 As New SqlCommand("sProvider", myConn)
[code]....
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Jun 9, 2010
I am new to LINQ and trying to learn it. I have a stored proc which returns XML Raw and I need to call this proc using VB.NET and LINQ...
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Aug 6, 2009
I initially posted this in the wrong forum. I need help getting this to run properly. I'm trying to construct a fractions calculator. In order to complete it, I need to do it like this:Using Select Case statements, four Function procedures should be called based on the operation selected. Each Function procedure will calculate the correct operation and return the Decimal value to the calling procedure. The original procedure will print the result.
Now, the result should be calculated to the hundreths place and the input values should be validated by a Try-Catch Block.And of course, I've been having trouble with how to do this. I've attempted many times and this is what I have so far:
[Code]...
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