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)
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.
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].....
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.
View 3 RepliesLet'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 RepliesHow would you create and use a delegate to update the text of the main form from the DoWork event of a backgoundWorker?
View 4 RepliesI am trying to learn Background worker and have written up a very simple app to understand this process. My form has a
textbox and a label. When the user clicks on the button, it updates the label with the value that they have entered into the textbox(I know this can be done elsewhere in the code besides the dowork event, I am just
testing and learning). Please help..I am not sure what I am missing. The label does not update.
[Code]...
I just want to to change a label name from the backgroundworker, the code is plain simple:
label1.text = WebBrowser1.DocumentTitle and the error returned would be "Specified cast is not valid".
Now running the code from a button would do the job, but from the bgworker not, and I can't seem to get around it.
I place some code below to simplify the process.
1) I am trying to use background worker to download a large file and update a progress bar to reflect the changes as the large 5GB file is being downloaded, and also update percentage completed to the label.text(lblInfo).
2) As I was goggling I came across some info that a web client is needed to calculate the maximum size of the file and divide by 100 and you can stream it down with the web client. Reading it is one thing, implementing it is another as I spent week trying to get it to work.
UCPocoAPoco
Imports System
Imports System.IO
Imports System.Diagnostics
[code]....
I have question about Label.Text.
When run the code Form1 load together with Form2.On Form2 I have Label1.I need that Label.Text flicker or blinking.
I have a form that I am loading text (strings) from a database into a label.text (so the text from the database shows up into the label) I have done this code in a class that keeps all my database stuff seperate.
Public Function getQuestions() As List(Of String)
Dim question As New List(Of String)
objConnection.Open()
objReader = objcommand.ExecuteReader
[CODE]...
Within the form that the label is in I have done this code
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Label1.Text(db.getQuestions().ToArray)
End Sub
I am basically making a quiz, so that when the form loads, question 1 is on there is 4 possible answers. You then press next button and it goes to the next question.
Is there an effecient way to give one label the ForeColor, BackColor and Text of another one of 3 possible labels? I need to do this frequently for a dozen labels in a windows form.
View 2 RepliesI am using a label to display a song for an mp3 player. I wanted to scroll the text inside the label for anything that is longer than the label width. I figured out the width of the label and if the width of the text inside the label is longer. But I have no idea how to turn this into subtracting parts/pixels of the text currently displayed and how to append the subtracted parts to the end of the new text.
Sub f1timer2tick()
Dim g As Graphics = f1l2.CreateGraphics
Dim s As SizeF
If f1l2.Text.Length > 19 Then
[code]....
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.
basically i need to change the text of a label where the name of the label comes from the value of a variable.So, for example,
Dim x as String = "lblTarget"
Dim y as String = "Target Text"
In this case the text of "lblTarget" would need to be come "Target Text". Basically, the label that is named the value of variable x would need to take on the text of variable y.
Is there any way to detect if the text in a label is longer than the label itself (assuming autosize is set to false)? I want to trim the text in a label so the last line is a finished sentence (everything after that sentence is removed). I hope you understand what I mean.
I want to go from this:"Hello. This is a test string. Most test stri..."
to"Hello. This is a test string."
Is there any easy way to do this?
I have a BackgroundWorker and using a delegate to update an UI on a different thread. Everything is working except the "lblInfo.Left = (Me.Width / 3) - (lblInfo.Width / 4)".I need this line since it allows me to center the text on the UI as I have several Subroutines and they all have various lengths in text. pass the lblInfo.Left = (Me.Width / 3) - (lblInfo.Width / 4) from the delegate so I don't get a IllegalCrossThread.
Delegate Sub SetLabelTextInvoker(ByVal lblInfo As Label, ByVal Text As String)
Sub SetLabelText(ByVal lblInfo As Label, ByVal Text As String)
If lblInfo.InvokeRequired = True Then
[code]....
I am trying to execute the following line of code within the DoWork event of a BackgroundWorker object: [code]
View 1 Replies 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.
How to Use of Backgroundworker while open a large text file
View 3 RepliesIn 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]....
I am creating a Pizza Order program as part of my coursework college. why something isn't working.
Quote:
lblTotal.Text = Val(Form2.lblPizzaTotal.Text) + Val(Form3.lblDrinksTotal.Text)
The code above is what I am using to add the Value of Label 1 (Pizza Total) and Label 2 (Drinks Total), however it seems that in the final total it doesn't appear to add the value of Label 2.
I am having trouble adding label.text, datetimepicker.text and ComboBox1.Text into listview1 box.I have set up multiple columns, one for the label, one for the date and one for the combo box text. All i have done is:
ListView1.Items.Add(DateTimePicker1.Text)ListView1.Items.Add(TextBox1.Text)ListView1.Items.Add(ComboBox1.Text)
How do i add these in the different columns so that they are all in one single row.
I have a label that reads a random line from a text file and that string becomes the text for the label.
Now the problem; the label will only work if it is clicked because the event handler is click.What I need is this to work automatically at startup. In other words, it should change the label's text to the random string of the text file on startup of the application.
Here is my code.[code..]
I cant seem to find any link or topic regarding my problem. I have 2 forms in a project, form one has labels and adjacent combobox while the other form (form 2)has textboxes with adjacent combobox. I am supposed to change the text property of the labels using textbox entry from form 2 and add/delete/change combobox contents in fom 1 using entries combobox at form 2.
View 13 RepliesI would like to know if there was a way to loop through all the checkboxes on a form and if the checkbox is checked then I need it to copy the text from the checkbox and the label. Thera are 23 of these labels with two checkboxes for each.I need to be able to paste this in notepad and have it formated as such
Yes 1. Are you older than 18?
No 2. Do you like dogs?
I want to force all capitol letters in a label and when text is input into a text box. How can I do this?
View 1 RepliesI tried to update the button text on a form from a backgroundworker.do_work event, and it failed, with the usual cross-thread exception message.However, by pure chance, I also tried to update text in a system.windows.form.toolstripstatuslabel also from this backgroundworker.do_work event, and it DOES work. Question: why is this? Is it perhaps because theres some kind of implicit shared behaviour with system.windows.form.toolstripstatuslabel?
View 4 RepliesI am wondering if there is a simple way to make the text to speech occur after the updating of label.text
If I have the following:label.Text = "words words" voice.Speak(label.Text)
I would like the label on the form to display "words words" before it speaks. I'm a beginner with vb, and the only thing I could come up with was to use a timer. Just wondering if there's a simpler/more sophisticated solution.
I have this problem but I already simplify the code as below:Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Label1.Text = "hello"
System.Threading.Thread.Sleep(5000)
'MessageBox.Show("hahahaha")
Label1.Text = "world"
End Sub
What I'm trying to achieve here is, after I click the button, the label1.text should change to hello, and after that to world. But I couldn't achieve that. Instead when I click the button, it just paused for 5 second and displayed world.System.Threading.Thread.Sleep(5000) The code is just a dummy for a loop that I have.