I have this code that checks if a thread or page has changed. But it always says it has changed. Because it does. Im currenlty checking the whole html page but i dont know a better way. Hers my code.
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
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I have a parent page and child page, both aspx. All is working, but now I would like to close child page, if user leaves child popup page and goes back to parent page and clicks on something else like page index of Gridview. I CANNOT close popup child page if user goes to another app, or some other location, I only want to close if something on parent page is changed.
I have the PageIndexChange Event set up for other purposes, I would just like to add some functionality, perhaps a script manager to close the child popup page if the Gridview index is changed, java or another way which ever works best.I think I might also need to check if the child page is even open.
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im developing an application that constantly checks a particular webpage for changes in the page. im using the webbrowser.documenttext to read changes in the source, its working great. until when i tried to use webbrowser.refresh(), an ugly popup that says. "To display the webpage again, Internet Explorer needs to resend the information you've previously submitted.If you were making a purchase, you should click Cancel to avoid a duplicate transaction. Otherwise, click Retry to display the webpage again."
View 2 RepliesI have a class that needs to check for errors in the data contained in a object.The routines that will check for errors could be implemented in concrete interfaces of supertype IErrorCheck. That way error checks can be discrete and added or removed from the class that requests the error checks.Each IErrorCheck implementation would be programmed against the supertype IErrorCheck (Strategy).But it would be nice not to recompile when checks are added or removed.Is there an accepted procedure for abstracting the error checks all the way out of the program, such as to read the checks from a file?
View 2 Replieshow can i allow a progressbar to be changed on a seperate thread? my code keeps saying that i cannot access it because it was created on a seperate thread:
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If it is not worth it, it is not fun - you say programmers are boring but i say they are worth it.
The code has gone bad. It is in debug mode and jumping around everywhere.
Error = "The process or thread has changed since last step."
Here is the code. I just create the file "start.csv" to initialize the shell command. This is very unstable for some reason. When I run line by line in debug mode it starts jumping around irrationally. It gives me versions of the above error.
Option Strict On
Option Explicit On
Imports System.IO
Module Module1
Public WithEvents Tmr As New Timers.Timer
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I would like to take blank secure stock paper and convert it in to a check.
I know you can get magnetic toner and print MICR.
The question is What is the actual font to use or should i get a package and send the data to it to print the check?
Has anybody done it successfully without having to resort to pre-printed checks.
Can not resolve this. Two radio buttons data binded inside a group box.
Click one thats not checked. Both un check. Must click again
Possible related situation here [URL]
writitng the my.settings manually.
I'm trying to write a little utility which will check periodically and tell me if/when a web page's (could be any URL) content has changed. I've read the other postings but they don't really answer my question (as far as I can tell).I know for static pages there is a last-modified header. However, what about dynamic pages? I got Oli's comment that storing a hash of the contents works but that's not really idea because the page might simply have a time stamp on it (the date-time that the page was produced). Clearly, in this case, the content would be different on every single request even though nothing significant has changed.So, now I'm thinking to tie it to a percentage of 'changedness.' Something like, more than 5% changed will cause the 'changed' logic to run.
View 3 RepliesVb.net For each currentFarm in ......
If urlQueue.Count > 0 Then
Debug.Assert(currentFarm.isBusy = False)
Debug.Assert(currentFarm.WebClient.IsBusy = False)
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The commented code won't work. That's because by the time the thread start, the variable currentFarm have changed. So I create a new function and cache the currentFarm in the function parameter. No there will be a cache of currentFarm address (object is always a pointer) on a stack and that address is the one being passed to the System.Threading.Thread constructor.
I have written a multithreaded crawler and the process is simply creating threads and having them access a list of urls to crawl. They then access the urls and parse the html content. All this seems to work fine. Now when I need to write to tables in a database is when I experience issues. I have 2 declared arraylists that will contain the content each thread parse. The first arraylist is simply the rss feed links and the other arraylist contains the different posts. I then use a for each loop to iterate one while sequentially incrementing the other and writing to the database. My problem is that each time a new thread accesses one of the lists the content is changed and this affects the iteration. I tried using nested loops but it did not work before and this works fine using a single thread.
Here is my
SyncLock dlock
For Each rsslink As String In finallinks
postlink = finalposts.Item(i)
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Finallinks and finalposts are the two arraylists. I did not include the rest of the code which shows the threads working but this is the essential part where my error occurs which is basically here postlink = finalposts.Item(i) i = i + 1
ERROR: index was out of range. Must be non-negative and less than the size of the collection. Parameter name:index
I tried copying it to a new list but dosent work.
I have a content page which contains an UpdatePanel and has a combobox. When the combobox value is changed I want to change a label in my Master page. So, the main problem for me is that I don't want to make a full postback with every combobox value changing. Is there some trick to overcome full postback?
View 1 RepliesI've been reading up on asynchronous function / web pages for ASP.NET 3.5 (we're not using v4 yet) but the ones I've seen all focus on performing a background task but then still coming back to finish up and send the response, after the task is complete.
What I want to do is simply kick off the background task (in this case a call to a web service) but then return a response to the browser immediately - ie. without waiting for the asynchronous task to complete. I don't even need to know if it succeeds or not.What is the best way to do that? I can't seem to find examples of kicking off what you might call an "orphan" background task in ASP.NET.
I thought of doing it via a javascript Ajax call on the page I show to the user, but the information passed to the web service is sensitive, so that's out of the question. But that kind of illustrates what I want to do.
[ed] Another idea: Is there an event in the ASP.NET model I can use which occurs after the response has been sent to the browser and the connection closed? ie. So more processing can occur without the user waiting for it?
I changed my Username on my computer from i.e. "xxxxxx x xxxxx" to "Dennis"
VB 2008 during a compile gave me the following error: Error reading icon 'C:Usersxxxxxx x xxxxxAppDataRoamingMicrosoftVBExpress9.0VSProjectApplication.ico' -- The system cannot find the path specified.
The file "VSProjectApplication.ico" is in 'C:UsersDennisAppDataRoamingMicrosoftVBExpress9.0'
Somewhere in the VB2008 "configuration" files I believe that I need to manually change the old path to the new path.
I found the old path in the ".suo" file. The ".suo" file is not a text file. How can I edit the .suo file, save it so that it will work?
on my Form I have a DataViewGrid and some textboxes with a save button (they are filled with additional data of the selected row).Save is disabled first, when I change something in the textboxes the save button is enabled.When the user changes a gow in the grid, I want to ask before changing the grid row, if he wants to save (if the button is enabled).I am using RowEnter but this is too late, then the selected row already changed (and my textboxes already got new data)...What event can I use to ask if I should save stuff before the user changes a row?Something like BeforeRowChanging with a chance to cancel changing the row?
View 2 RepliesIn one application, I need use 4 simultaneous threads.When the threads finished, I need to update the text of a TextBox.So, I create 4 Textbox, and I wanna the threads change the text to FINISHED.Each thread change one distinct TB.I use this "example"
Dim Terminados As Integer = 0
Private Sub frmEnviarMensagem_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Timer1.Enabled = True
Timer1.Start()
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The problem is, I have an error in the red lines.The error is: INVALIDOPERATIONEXCEPTION "Cross-Thread operation not valid: Control tbPlaca1 Accessed from a thread other than the thread it was created on."I don't use cross threading. Each TB only was accessed for the correspondent thread, and for the "main program".
This is the error message I am getting:
"Cross-thread operation not valid: Control 'Panel1' accessed from a thread other than the thread it was created on." The reason I am getting this error is because I am opening up a new form and then calling these three things:
Panel1.Show()
Label1.Show()
Label2.Show()
why I get this error message because it doesn't occur normally if I open Form2 after closing Form1, it only occurs when I open Form2 after closing Form4.
I have done a program using vb2005 to display reading from my microcontroller bs2 board but have encountered some problems. My code are as follows.
Dim Stop_Rx As Boolean
Private Sub btnRead_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnRead.Click
SerialPort1.Open()
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I've encounter an error which is, (Cross-thread operation not valid: Control 'txt1' accessed from a thread other than the thread it was created on.)
When my client try to connect to server I'm getting this error : Cross-thread operation not valid: Control 'l_users' accessed from a thread other than the thread it was created on.
Private Sub _socketManager_onConnectionAccept(ByVal SocketID As String) Handles _socketManager.onConnectionAccept
l_Users.Items.Add(SocketID)
End Sub
Would anyone be able to help me here please. I'm fairly new to VB.net and threading so im just trying to figure out what is happening.When I debug this I am getting the error thread operation not valid: Control 'ProgressBar1' accessed from a thread other than the thread it was created on.
I'm a little lost as to why the error is occuring or how to fix it. I've had to put the progress bar in a separate thread otherwise the GUI crashes
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My understanding is that thread.join will suspend the execution of code on the calling thread until the spawned thread finishes or is aborted...
With that in mind, I tried this:
For i = 1 to 50
threads = New Thread(AddressOf test)
threads.IsBackground = True
threads.SetApartmentState(ApartmentState.STA)
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However, the rest of the code runs when the loop finishes, not waiting for all the spawned threads to finish. Since the rest of the code needs the threads to finish (otherwise the rest will error).
I have written an application that loads a form - frmCad as well as AutoCad. It does this via a class which detects when AutoCad quits.
Friend Class CadApp Private WithEvents AppObject As AcadApplication... Private Sub AppObject_BeginQuit(ByRef Cancel As Boolean) Handles AppObject.BeginQuit RaiseEvent Quit() End SubEnd Class
My main class loads frmCad as well as CadApp.
Public Class Cad Private WithEvents frmCad As CadForm Private WithEvents app As CadApp... Public Sub ShowForm() If frmCad Is Nothing Then frmCad = New CadForm frmCad.Visible = True End Sub... Private Sub app_Quit() Handles app.Quit frmCad.Dispose() frmCad = Nothing .... End Sub
When I debug the program, it stops at frmCad.Dispose()The program continues to execute, but all the code after it fails to work.Looking more carefully I get an error message which contains:-Cross-thread operation not valid: Control 'Autocad' accessed from a thread other than the thread it was created on.
My error:Cross-thread operation not valid: Control 'label2' accessed from a thread other than the thread it was created on. I want to be able to give my Public RunBot() sub access to edit Labels, buttons, etc without an error.
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I'm getting the 'System.InvalidOperationException' error on acccessing a thread from other than where it was created. My code is:
'Required by the Windows Form Designer
Public components As System.ComponentModel.IContainer ' changed from private
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My problem is Cross-thread operation not valid: Control 'statusHO' accessed from a thread other than the thread it was created on.
System.InvalidOperationException was unhandled
Message="Cross-thread operation not valid: Control 'statusHO' accessed from a thread other than the thread it was created on."
Source="System.Windows.Forms"
StackTrace:
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i used it and it works fine then. but as it is mentioned its not a good practice to use it. So what should i do? is it ok if i use this as i am not able to use correct practice. Mine application is not for enterprise purpose. its just my class project, and it works fine even if i put application working in background. System works ok. I dont know how to correct this error.As i dont have that much knowlege of threads.
So please guide me how to fix this in correct way otherwise i am force to go for bad programming practice
Please refer to Windows Mobile Developer Center > Smart Device Development Forums > Windows Mobile Development > Appendtext not working for all my code details
Cross-thread operation not valid: Control 'lv1' accessed from a thread other than the thread it was created on.
Dim lvi As ListViewItem
For Each lvi In lv1.Items
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Ok i have a Form with the following
Private Sub frmMain_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
txtNotepad.Text = LoadFile("notes.txt")
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I have a text input in textbox1 in tab page 1 and i want that text from textbox1 will be displayed in textbox2 in tab page 2.
View 3 RepliesI wrote a page Page method in my aspx page. in web service method I need to call FindControl method return textbox and get text box value. But my findControl will take MasterPage object to iterate.
see my code
<script type = "text/javascript">
function ShowCurrentDateTime() {
$.ajax({
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How to pass Master Page object or Page to Page method?. So I can use in Sared method.
Is there any way I can access Textbox value directly in Page method? I need access couple of controls in Page Method.
HOW TO RUN THE JAVASCRIPT FUNCTION ON PAGE ONLOAD EVENT IN CONTENT PAGE OF MASTER PAGE.? means i have masterpage and the content page of master page namely default.aspx in vb.net.i wanna run javascript function in Default.aspx and i have called the function body onload in master page.when i run my website it shows the error "" Microsoft JScript Runtime Error : Object Expected ""
View 4 Replies