Title:
Improve Basic Multithreading Code
Name:
Abhijeet Rana
Date:
2012-05-11 2:08:03 AM
Comment:
Hi All,
If you copy and pest above code as usual in .Net the you will get error saying "Cross-thread operation not valid: Control 'cmb1' accessed from a thread other than the thread it was created on." as i did that so i got this error
Error occurred because main thread is running for form and listbox control is not accessible at this point
So i have modified this code as below-
Imports System.Threading
Public Class Form1
Inherits System.Windows.Forms.Form
Dim th1 As Thread
Dim th2 As Thread
'Declaring Delegate here
Private Delegate Sub proc1Delegate
Private Delegate Sub proc2Delegate
Private Sub Form1_Load(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles MyBase.Load
th1 = New Thread(AddressOf proc1)
th2 = New Thread(AddressOf proc2)
th1.Start()
th2.Start()
End Sub
Sub proc1()
'Calling Dalegate here and passing addressof Proc1
Dim DelProc1 As proc1Delegate(AddressOf proc1)
Dim iCount As Integer
If cmb1.InVokeRequired Then
cmb1.InVoke(DelProc2)
Else
For iCount = 1 To 10
cmb1.Items.Add(iCount)
Next
End If
End Sub
Sub proc2()
'Calling Dalegate here and passing addressof Proc2
Dim DelProc2 As proc2Delegate(AddressOf proc2)
Dim iCount As Integer
If cmb2.InVokeRequired Then
cmb2.InVoke(DelProc2)
Else
For iCount = 11 To 20
cmb2.Items.Add(iCount)
Next
End If
End Sub
End Class
* Correct me if i wrong
|
Title:
eagle
Name:
desert eagle
Date:
2011-10-25 7:18:46 AM
Comment:
desert eagle want to know how to work through multiThreading
|
Title:
Good
Name:
Farogh Ahmed
Date:
2011-05-31 10:38:57 AM
Comment:
Very good explanation with example.
Thanks,
|
Title:
it is nice article for beginner
Name:
Anjanareddy
Date:
2010-11-18 6:15:24 AM
Comment:
It is very useful for beginner.i tried ur program but when i give breakepoint that time it work perfectly.is it need brake point while debugging ?
nice article.Thank You
|
Title:
How to overcome- "Cross Thread Operation" problem
Name:
Balakrishnan.S
Date:
2010-07-23 2:33:58 PM
Comment:
When running the downloaded appliation Showing error "Cross-thread operation not valid: Control 'cmb1' accessed from a thread other than the thread it was created on."
Please give me the solution......
|
Title:
article is really good
Name:
neha
Date:
2010-07-17 1:56:12 AM
Comment:
information regarding multithread concept is very good n easy to understand. Its very helpful for the beginners
|
Title:
ss
Name:
ss
Date:
2010-07-08 8:19:37 AM
Comment:
When running the downloaded appliation Showing error "Cross-thread operation not valid: Control 'cmb1' accessed from a thread other than the thread it was created on."
|
Title:
Thank you
Name:
Bilal
Date:
2010-05-16 3:40:40 AM
Comment:
many thanks
|
Title:
multitreading
Name:
Amin Rasmin
Date:
2010-03-30 9:25:29 PM
Comment:
thank u for ur information, it's help me, i'l try to use it.
|
Title:
It doesn't work
Name:
Anonymous
Date:
2010-03-19 5:34:30 AM
Comment:
This article is good and easy to understand, but the code just doesn't work for me. I have created a C# web app and filling listboxes. Below is my code.
protected void Page_Load(object sender, EventArgs e)
{
Thread th1;
Thread th2;
th1 = new Thread(Proc1);
th2 = new Thread(Proc2);
th2.Start();
th1.Start();
}
private void Proc1()
{
for (int i = 1; i <= 10; i++)
{
ListBox1.Items.Add(i.ToString());
//Thread.Sleep(100);
}
}
private void Proc2()
{
for (int i = 11; i <= 20; i++)
{
ListBox2.Items.Add(i.ToString());
//Thread.Sleep(10);
}
}
Some times it works and only populates the ListBox 2 as I have called thread 2 on top of thread 1. If I call thread 1 before thread 2 it will populate only List Box 1.
Even with the Thread.Sleep uncommented the code wont work.
Can anyone please tell me what is wrong with this piece of code as I am totally clueless.
|
Title:
example of multithreading in microsoft word
Name:
mariyan
Date:
2009-10-08 5:38:37 AM
Comment:
can you give some example of multi-threading in microsoft word
. because i not yet to understand about it process when microsoft office word is runing
|
Title:
I have this same problem like Eman mentioned here
Name:
kumar
Date:
2009-07-02 1:16:00 PM
Comment:
I dont see second combo populating until I debug the code step by step using break points. Am I doing something wrong plz clarify?
|
Title:
Best Article to Start with
Name:
Geetha
Date:
2009-05-28 3:45:53 AM
Comment:
Hi Sandeep,
The article is really nic to understand basic of mutithreading.
Its useful for beginners.
|
Title:
nice
Name:
Dima
Date:
2009-04-12 9:07:59 PM
Comment:
very nice ............
|
Title:
Nice Article
Name:
Jignesh Patel
Date:
2008-08-19 9:54:41 PM
Comment:
Very nice ..easy to understand for beginners..
Thanks..
|
Title:
RE: It won't work
Name:
Ibrahim mohsen
Date:
2008-05-22 9:48:07 AM
Comment:
you shouldn't access any controls inside threads
you may make flag and in the end of thread method raise this flag and make timer to check if this flag is raised.
if it is raised access what you need of controls
|
Title:
It won't work
Name:
Abhishek
Date:
2008-04-28 3:58:57 PM
Comment:
Cross-thread operation not valid: Control 'comboBox2' accessed from a thread other than the thread it was created on.
I'm getting this error. I'm not able to do the multi-threading in any way on windows systems. Anybody have any working sample/example?
|
Title:
Shallow Coverage
Name:
ApuDeb
Date:
2008-04-26 2:17:48 AM
Comment:
Hello Sandeep, I found the coverage of the topic shallow and found a lot of room to improve it.
|
Title:
kill a thread that is spawned by another process
Name:
Mia
Date:
2008-01-24 3:44:06 PM
Comment:
I have an app that starts a thread. The threads opens a new aspx page and runs a process to fill the page with data.
The currentThread in the new aspx page is the currentThreadID of the app and not the threadID of the new thread. How can I kill the new thread from the new aspx page. if I just kill the currentThread, it will shut down the whole app.
|
Title:
Very Simple
Name:
Abdulla Hussein
Date:
2007-09-28 5:58:50 PM
Comment:
Very Simple Articals , and it is help me to understanding MultiThreading in a nice way . Thanks :)
|
Title:
Multithread
Name:
Rajesh
Date:
2007-04-04 2:18:12 AM
Comment:
Nice article
|
Title:
need help
Name:
Dhananjay k
Date:
2007-03-21 8:32:20 AM
Comment:
hi,i am trying to make online multiplayer game(card game like poker)now in current state the game is almost completed and in LAN it working fine. but whn i try to use online database(ie fm remote db server) the game sleeps can anyone suggest me hw can i solve the prob. ( using vb.net and sql server 2000)
|
Title:
possibility
Name:
balaji
Date:
2007-03-16 7:22:59 AM
Comment:
i want to move multiple objects and , iwant to see at run time those actions in asp.net 2005 version
|
Title:
answers to questions
Name:
KraGiE
Date:
2007-02-13 6:44:19 AM
Comment:
First off, this is a pretty good beginners look at multithreading in .net. Would be nice to see more low level info, and practical do's for threading.
1) annie xavier
if you're only using one thread, it would probably be better not to sleep it. However, it all depends on the scenario itself. Can you use a timer and/or an event callback that will trigger your working thread to start?
2) Eman
Typical problem with debugging multithreaded applications. Get used to utilizing thread names, and conditional breakpoints. you can also use windbg if you've learned how already.
|
Title:
Doubt
Name:
annie xavier
Date:
2007-02-07 4:52:49 AM
Comment:
i am not using threads in my application. Now in my application i need to wait for soemtime even before i execute a piece of code. Is it ok if i specify thread.sleep in the main thread itself?
|
Title:
there is a proplem
Name:
Eman
Date:
2007-01-28 5:39:24 AM
Comment:
i have a proplem that wehen i run a project motr than once thread dosen't work unless i debug it line by line by using
breakpoint
why????????????????????
please give me answer by mail orin this page quickly
thanks
|
Title:
Hi
Name:
Padmapolisetti
Date:
2007-01-11 4:35:46 AM
Comment:
Hello,
Ur material helped me a lot in learning about the threads.
can u provide some more material on threads in depth.
|
Title:
hello
Name:
hassan hayek
Date:
2006-11-04 2:27:32 PM
Comment:
thanks
|
Title:
jj
Name:
ashish
Date:
2006-10-23 11:14:19 PM
Comment:
ur material is very good n m very satisfied n got new things from ur sites everything is worhty for me
|
