I'm using a While loop that loops a certain number of cycles (1-576) based on a value entered by a user. It's activated by the user clicking a "Start" button, But I would like it to be able to be canceled using, preferably, the "Escape" key. However, when the loop is going I can't get the program to recognize any keypresses.
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I'm trying to create an app with a backgroundworker to enable canceling a loop, but it won't work as I hoped it would.When I debug right after the line ThreadWorker.RunWorkerAsync() the programm goes directly to Private Sub ThreadWorker_RunWorkerCompleted and skips the Private Sub ThreadWorker_DoWork part, where of course the actual code is in (I've left that code out, it's about a 100 lines and without BGW it works).Does anyone have an idea what could be wrong with it?
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a wpf application starts a task to do some work asynchounsly. If i need to stop it how can I do that?
View 4 RepliesI received some good advice previously on parallel.foreach vs Task.Factory.StartNew. I have implemented both and have been surprised with the efficiency of both. I used the following link o try and understand exceptions and incorporate it to be notified if a task stops for any reason the program will detect it. Is there any definitive way to do this without wait() or waitall which will tie off the interface and other tasks running at the same time.
Try
pcounter += 1
Dim factory As Task = Task.Factory.StartNew(AddressOf FileParser.Module1.Main)
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I have a program in VB2008 and I need to execute a thread from differents Subs.Each time I start the thread I want to cancel the previous.Here an example:
Private Sub TextBox_Changed(ByVal sender As System.Object, ByVal e As System.EventArgs) Dim ThreadResults As New Thread(AddressOf ShowResults) ThreadResults.Start() End Sub Private Sub ckBoxAllRecords_CheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs) Dim ThreadResults As New Thread(AddressOf ShowResults) ThreadResults.Start() End Sub
I write in a textbox, TextBox_Changed fires, thread spend 4 minutes filling a dataset I check a checkbox, ckBoxAllRecords_CheckedChanged fires, thread spend 10 seconds filling a dataset.I dont want anymore the dataset of TextBox_Changed so I want to cancel its filling.
I've set up a background worker to search a directory for emails and if my specifi criteria (i.e. date ranges, contains a word) are fulfilled, then a list view is populated.I have this working absolutely fine - when I click search, the list view is populated as I watch - but when I press my 'Stop' button, which runs bg.CancelASync() it does not stop the process at all - results still populate in the list view as it was before.
View 1 RepliesI have a DataGridView in which I register customer orders.
The DGV has a column "PRICE", Price must be > than 100, and I control that in this way:
Private Sub DataGridView1_CellValidating(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellValidatingEventArgs) Handles DataGridView1.CellValidating
Dim newInteger As Integer
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I'd like to start by saying that simply though searching, DreamInCode has taught me alot about VB.NET. In fact, I would imagine without DIC as a resource, I probably wouldn't have been able to move forward and learn most of what I know now, just because I got stuck on some things here and there.Anyway, I searched around for information regarding how to "capture" a minimize event in VB.NET. I am working on the GUI for an application that I would like to have minimize to the system tray. Currently, instead of accomplishing this with the minimize function, I do it on the FormClosing event like this:
Private Sub MainFrm_FormClosing(ByVal sender As System.Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles MyBase.FormClosing
'Cancel the attempt.
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That code works, and upon making the form visible again with Me.Visible = True the form is restored to its original position. However, prior to the form being hidden, the window manager draws a minimize and restore effect before eventually hiding it. Any change to the WindowState _after_ hiding the form does not appear to have any effect, so when the form is unhidden it is still minimized.is there a way to capture Minimize events, and when captured, is it possible to cancel them in a manner similar to what I did with the FormClosing event?
Really wracking my brain here and I'm sure it's something simple I'm missing. Basically I have a form with two tabs. I'm checking the controls on each tab to see if they're dirty and want to prevent a user from clicking a tab if there are changes on the current tab.
I had thought if I check the dirty variable and just set the tab index to the one that hasn't been selected I'd be fine but every time I programatically set a tab's property, it fires off a bunch of the tab's events that just produce an undesireable result such as the right control set is showing but the wrong tab is selected. Here is the code for as close as I've gotten to getting it to work.
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I have a task that needs to be executed many times in a thread, so as to keep my GUI responsive. Right now I'm using the ThreadPool to accomplish the tasks, and it works perfectly. I get all the data I expect back from the threads, life's good. When those tasks are finished, I then fire off another set of threads to accomplish another set of tasks, in the same fashion. The work method of these threads uses a call to RegistryKey.OpenRemoteBaseKey, which does exactly that, opens a remote registry key. The problem is: if the user running the application does not have permission to open the remote registry the call will throw an IOException, but I expect this behaviour because the user does not have permission to do it. However, the call itself can take FOREVER.
I wrote the application initially to use delegate methods and used the WaitHandle.WaitOne() method on AutoResetEvents in a state object I passed to each delegate. I tried the WaitOne method using a timeout, which worked fine until I realized that even though the WaitOne timed out, the thread was still running. This is a problem because (from what I understand) processes are only given a certain number of ThreadPool threads and, once used, they must be finished in order to be released back to the threadpool. In my work method, I also have a variable that can be signalled when the thread should be stopped, but that (obviously) only works on code that I've written.how can I cancel a thread that's stuck on a .NET method? Is there some sort of garbage collection method I can call if I give it a handle?
Right basically if a checkbox in my application is checked "Close to system tray" then my form will cancel close and send to tray instead
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Protected Overrides Function ProcessDialogKey(ByVal keyData As Keys) As Boolean If keyData = Keys.Enter Thenme.currentcell.value = "Hello" ' Here i want to give text "hello" to the current cell is this possible
View 1 RepliesMakes the following statement about the code below:
**"The computer evaluates the loop condition in the Do...Loop statment to determine whether the loop instructions should be processed. In this case, the inputsales <> String.Empty condition compares the contenst of the input sales variable to the String.Empty value. As you know the String.Empty value represents a zero length, or empty, string if the inputsales variable is empty, the loop condition evaluates to True and the computer process the loop instructions. *If on the other hand the inputsales variable is not empty, the loop condition evaluates to false and the computer skips over the loop instructions.
Based on the code I think it is the opposite: ...that while the inputsales value is not empty it should evaluate to true and process the loop and if it is empty it should evaluate to false and skip the loop?
See below.
Option Explicit On
Option Strict On
Imports System.Globalization
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I know I am missing the obvious. I would like a label to show how many cycles in loop are left.
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I am constructing a program, i am new to Visual Basic, but i have past programming experience. I was wondering if anyone knew how to form a loop that could...lets say calculate the answer when two numbers are added together,and it would repeat this thousands of times, etc. And if there is a way, would it be possible to calculate the time taken to complete this loop.
View 5 RepliesI have written a function that gets the alexa ranking of a given url, now this function works perfectly but I want to loop through a ListView of urls and grab the alexa rank of each item (url) with my function.The code works great if I put a MessageBox in the loop to test that the function is returning a value but when I remove the MessageBox the loop does not work.I need it to loop through adding each result without a MessageBox stop in each loop.
vb
For Each Item In ListView1.Items
Dim result As Integer
result = GetAlexaRank(Item.Text)
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So I made a simple patform game where the player has to jump quickly while the platforms move to the bottom of the screen, as to not touch the bottom of the screen. But, I need to know how to create a loop to loop the locations of the platform. This means that after twenty or so platforms, the same platforms come up again, so that the player will have an "endless" game. I've declared all the platform's locations relative to the location of the first repeating platform:
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I assigned an integer as 1, and looped my program using:[code]I can recieve the packets without looping, but once i loop, i receive nothing.
View 29 RepliesI have this little application that runs a SQL query works great, now I want to have a Start Button run the and display results then System.Threading.Thread.Sleep(300 * 1000) for 5 min then run again and display results and loop till I buttonstop_click. unsure if the sleep is the best method.
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I am new to VB programming. I have the following code. When I execute my program only the last value from the loop is displayed in the label. I do write my code so that all of the values (years 1 to 5) show up in the label?
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I'm completely new to working with more than one thread at a time but I've been reading up on backgroundworker quite a bit today. I get the general idea and think I could use it ok if it weren't for the fact I have a loop in a loop and I don't think they could be run inside a single thread together
View 4 RepliesHow do you convert a loop to a for loop
View 5 RepliesHow would I convert this Do While loop to a For...Next loop? I can't figure it out.
intCount = 0
Do While intCount < 50
lstOutput.Items.Add(intCount)
intCount += 1
Loop
Dim count As Integer
For count = 1 To 10 Step 1
Dim But+count As New Button
myButton+count.Width = 100*count
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Dim But+count As New Button => How to make it work
I'm slowly learning about loops. I have a couple of questions
1) When a condition is being tested.. what does that mean? I don't understand the "condition" word.
2) What is the difference between a loop that never ends and a loop that ends?
I have the code for the loop that ends and the loop that never ends. I can see the difference in the code, but I don't understand what is making it different. Here is the code below.
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I use the following code to add a row to an existing table
Dim newLineRow As DataRow = dsAccountDetails.Tables("Ph").NewRow()
newLineRow("Service TN") = "test"
dsAccountDetails.Tables("Ph").Rows.Add(newLineRow)
When I run the code it adds a single row to my table just like I want it to. However, when I put it in a loop it errors and tells me that the row already exists. The number of rows is always changing and I want to build the table from arrays. Why isn't the following working?
Dim a As Integer = 0
Dim b as integer= 5
For a = 0 to b
dsAccountDetails.Tables("Ph").Rows.Add(newLineRow)
Next
Currently, lets say that I have this code:
While r <> "HI"
r = RandomStringGenerator(1)
time = time + 1[code]....
how can I make it so that i can say basically this:
While r <> "HI" Or While r <> "BY"
r = RandomStringGenerator(1)
time = time + 1[code].....
But it still doesn't work! What's up with this?
Why does any app I make use 50% CPU while in a loop, even if the loop is doing simple evaluations, I've added Application.DoEvents() which stops the application hanging, but 50% is rediculous, what gives?
View 10 RepliesI have got this far and if you run it, it will do what you ask. Now when I type in 99999 or -99999 it will not end. Can someone tell me what I am doing wrong. I am suppose to loop until a sentinel value of -99999 is enter for previous meter reading.[code]...
View 2 RepliesI am working in VB 2008, Like vb 6.0 I used 'Do Until' loop in record set. I am now using 'For Loop' command for moving record in a table in vb 2008. But I want to use 'Do Unitl' Loop in record set moving record pointer to next record. Is it possible. If possible please show me with example.
View 4 Replies