I have an application I'm working on that is essentially an Excel workbook generator (special input files for our wireshop machinery). Therefore, it's process is lengthy.
Is it possible to build a Cancel feature while it is looping through its collections to process these files?
If so, would I need to implement multi-threading?
While I print or preview a large bitmap, VB.NET show a small window with a cancel button.
I do I detect that the CANCEL button was pressed, so I can abort my PrintPage event before the current page is completely rendered?
I have got my multi threaded application running which is a Windows Service Project.
Basically when the service starts it starts a thread listening on a port for connections. The reason I started this on a new thread was so I could easily control it and not lock up that main worked thread.
Now on that thread when a client connects it dynamically assigns them another port number that is not currently in use and starts a new thread listening on that port and waits for the client to connect to do the actual data crunching.
So basically I have my main project thread, a Main listening thread then the possiblity of 0 to 100 more threads for each connected client.
Now this project should always be running but in the event it needs to be shut down (or server rebooted etc) I want to be able to shutdown the threads safely.
I can down my main listening thread safely but my trouble is all those other possible threads. What I would like is if the service is called to stop I want any of those other possible running threads which would have an active connection to the client to send a simple command like 'STOP' then close the connection gracefully (MyConnection.Close) and end itself.
The only solution I can think of which I don't really want to do is have a global varible (StopThreads as Boolean) and after each command in the thread check that boolean and if its set to true jump to some code to do what I want and end the thread but there must be an easier way? Or is this the best way?
I have made a project on offline railway reservation ticket and cancellation and management wel i have included following things: form wise
1}welcome page (containing news , updates about the software )
2}registration n login page
3}main menu (Containing links to all tools and services i included in software)
4}ticket regestration (fare calculation and deduction and special discounts included)
5}ticket cancelation
6}PNR CHECK
7}FEED back form
9}Splash Screen
10}Rules n policies ,refund rules
11}Gerneral information
12}RTI act
13}Railway Map
15}Service area Covered
16}Train Halt Stations , total Halts per train according to Journey and distance Stations Between Journey
17)Trains and stations Codes
18}Train Arrival and Departure Timings
Thats It, Full database on Ms Access ..and Text Strings.Now Is this enough Or shall i Do add some thing More ... if u think its incomplete Plz suggest Some topic that i can add to This project.
I'm using a background worker to in an Excel VSTO application to throw up a progress dialog box with a status bar and a cancel button to escape from long running calculations. It's working really well, except for one issue. I'd like to use a Modal Dialog, so that the UI behind the dialog gets locked up, instead of a Modeless Dialog. If I use .ShowDialog() instead of .Show(), everything is great until you hit the Cancel button on the form. Following things in the debugger, the cancellation happens, it just takes somewhere in range of 30 seconds. If I use .Show() on my form, then the cancellation occurs immediately as it should.
[Code]...
i want a code that if a process that i picked is no match in a process list that process that i picked will start
View 4 RepliesTrying to create a button that when clicked will check to see if a certain process image is running and if that process is running give the process focus. If the process is not running then start the application.
View 9 RepliesWhats happening is I run the code below and get the following error "The system cannot find the file specified". I've read that with UseShellExecute set to false that you can't use WorkingDirectory.
Dim Password As String = "password"
Dim SecureStringPassword As New System.Security.SecureString
For Each c As Char In Password
[Code].....
I'm using Visual Basic 2010I've created a ListBox and a BackgroundWorker using designerI want to change the location of listbox using backgroundworker but I get the error as follows:"InvalidOperationException was Handled by user code:"Cross-thread operation not valid: Control 'ListBox1' accessed from a thread other than the thread it was created on
View 10 Replieshow to do serial communication using threading in vb.net 2008,
View 1 RepliesI have an application that requires the use of many threads. How do i monitor the memory consumption of my application?And how can i monitor the CPU usage of my application if possible?And is it possible to monitor the memory consumtion and CPU usage of each of these threads?And is it possible to limit or prioritize the memory consuption or cpu usage of the whole application or of each thread?
View 5 Repliesafter i get a successful ping response i need to send an HTTP request to the device examine the response and then display it. i'm trying to multi thread the 2nd bit with no joy so far.
Imports System.Net
Imports System.Net.NetworkInformation
Imports System.Threading
[code].....
I would like some advice on multi-threading. I currently utilize two threads, one for the GUI, and the other for calculations. This works well, but I want to improve my multi-threading techniques. Currently the data is with the calculation thread, and this occasionally this will cause a slow down. I want to put the data on its own thread. Giving me three threads, Data, UI, and Calculations. This should improve responsiveness, and not be overwhelmingly complex.
My problem is, this no longer fits into the parent child relationship well. All three threads need to interact with each other. My question is, what is the better way of dealing with more than two threads, when all the threads need to interact with each other. Should I pick one thread as the ultimate parent, say the data thread (I pick this one, because it seems to me this thread will be the most free.) Then have the calculation thread and the UI thread children of the data thread. Then when I have a need for the UI thread to explicitly call the calculation thread, I do this through a function in the data thread.
I have an application that I need to automate where at a certain time each day, say 6pm, it will run a certain method(which is to check a database for key terms and then access the api to search for these terms). But there is the main process which is running all the time accessing the stream api so when the search is complete, it interrupts the stream and hands over the new terms. Now I thought of adding the .exe file to windows task scheduler but not sure if that would work. The stream method runs indefinitely and at 6pm each day another process needs to run. I thought of using the system.threading.task TaskFactory but I am using visual studio 2008 ( I do have .net framework 4.0)If it launches using the task scheduler as 6pm with my code logic as follows:[code]
I see how this would eat the CPU...the streaming process is basically following a list of user profiles listening for new activites and storing these as XML files. This a real time feed to an API. At a specific time once a day, a second process needs to go access a database for new ids, and if there are new ids, then go to a search API and get new user profiles. This is the main criteria..once the new user profiles are found, the list that the stream users needs to be updated so the process will be interrupted for a second or just paused and then continue processing.
I'm just looking for other people's thoughts and opinions on the way I have done something.I have a console application which needs to connect to various computers and reset the local admin password on each one. I got it all working but then decided that as there are a lot of PCs, it would be a good idea to use the thread pool to do a few at the same time.The problem is, I need this program to be run without any human interaction - so I cant just use ThreadPool.QueueUserWorkItem and pass it all of the computers to connect to, because then the program would exit after it had called QueueUserWorkItem for each one because there is nothing left for it to do. I cant stick a Console.ReadLine in there because like I said, it needs to be run automatically without anyone typing anything.
View 1 RepliesIs is possible for the server to give all clients that are connected to it a separate threading starting from 1-2-3-etc that will be display there username on a listview. Server can now connect to any of them by clicking on one of the items in the listview.
EX: Multi-Clients Connect to server ---> Server gives each one a separate thread starting with 1 ----> Client sends username to server -----> Server displays them on listview ---> Server can now double click or whatever on the item ---> Pulles up thread count and connects to it.
Wheres my error on this code...
Imports System.Net
Imports System.Threading
Public Class Form1
[CODE]...........
Basically what I want to do is that User will select how many thread w/c is the PickThread.value, then it will do the stuff.
i got inside
WebBrowser1_DocumentCompleted sub
the code below
WebBrowser1.Document.GetElementById("form").InvokeMember("click")
Call ProcessNextLine()
when it clicks this button it should load another page(Like log in)
Call ProcessNextLine()
takes next line from txt file (It's url) + navigate
but I want it to wait let the page load before calling "Call ProcessNextLine()" I tried System.Threading.Thread.Sleep not working?
What is the difference in using: BackgroundWorker1 or System.Threading.Thread
View 3 RepliesTrying to get System.Threading.Timer to work!! I am converting a small form based application to run as a services, The app just runs an monitors a folder and then when it finds a file to does some work on it. Having changed the form.timer to threading.timmer - The timer stopps working after a while. Below is a simple test services - when you look in to the text file it stops after approx 130 entries
[Code]...
How do I make a chat room that multi clients will be connecting to at once. Im trying to add a ping/pong method which is just msgbox that tells the user if the message was received. I know that you need a background worker for this but how do i handle all the msgs that are going back and forth to all the clients that are connected to the server
View 1 Repliesi have tryed using multithreading with my program with no luck/I just get a strange error thrown at me no matter what i try [code] Then i get this error:An error occurred creating the form. See Exception.InnerException for details. The error is: ActiveX control '6bf52a52-394a-11d3-b153-00c04f79faa6' cannot be instantiated because the current thread is not in a single-threaded apartment.
View 13 RepliesI'm not sure how to explain what's happening but it seems to be deadlock, i did search along the forum and actualy did find who had the same problem as i did. Unfortunatly i'm too new to this Threading and could not understand why does this deadlocks happen or how to avoid them.I'm using the following
Dim t As New Threading.Thread(AddressOf MyTestingSub)
t.Priority = Threading.ThreadPriority.BelowNormal
t.IsBackground = True
[code].....
I would like to know what are the usages for Threading or BackgroundWorker, and their implementations.I currently am running a UDP program, but the server freezes until the client sends the packet, which momentarily unfreezes the server, and then re freezes it.I have looked at the MSDN for them and they seem complicated :l
View 26 RepliesI am creating an IDE for a game script with similar functionality as the Visual Studio IDE (at least, some of it). The game script consist of code that looks visually a bit like C code. It uses braces to define the start and end of a 'class' and uses nested braces to define the start and end of an 'event' in a class.
What I want finally is to have two Comboboxes above the text editor, one that lists each Class and the other listing each Event. The comboboxes should also show the Class and Event that the caret is currently in, just like in Visual Studio.I have attached an example of such a script (you can open it with Notepad).However, here is a short example where you can also see how I "defined" classes and events:
class1
{
event1
{
[code]....
As you can see, the classes are the 'names' of each block of code, defined by matching braces { }. The events are the names of each nested block of code, also defined by matching braces { } but inside a class. There is only one level of nesting.As you can also see, the layout can follow the standard C-style layout, or a slightly different layout (using the opening brace on the same line as the class/event name), or even a completely chaotic mess. As long as the braces match correctly, the code is valid.So in short, the large blocks are classes, while the nested blocks are events.
What I want to do, is parse an entire script, and store all the Classes (and eventually, also all the Events, but let's forget about them for now). I want to store the Class name, start position (defined as the start index of the name), end position (defined as the index of the closing brace) and the full text (defined as the text between start and end position, so including the name).
vb.net
Public Class clsClass
Private _Name As String
[code]....
The code works basically by finding every first opening brace (the opening brace of each CLASS, not event), and then loops through the class (using a brace counter to keep track of the nested braces) until it found the last closing brace. It then stores the name, start, end and fulltext in a new clsClass and adds it to the list to return.
I have written a windows service that is meant to launch a notepad when a specific action happens. The problem i have is that even though the service launches notepad, the actual notepad it self is NOT visible. I know that it has been launced because i can see the process in the task manager. By the way the process is listed as a SYSTEM process rather than a process under my user name (i believe that is because my process is a "LocalSystem" one).
View 4 RepliesMulti-Threading. I have got a simple bit of code that will need to be repeated but with a chance of it overlapping the only complex bit is there will be a varible that will be different each time. so I was wondering if I put it in another Thread and store the varible within the thread code would that achieve what I am looking for? To make it slightly easyier once the thread is started and pulled the Varible in there will be no cross talking between the thread and main app thread (ie no progress reports, no aborts/suspends etc) Nothing will be feeding back on thread completion either, when it ends it ends.
This is what I have so far:
Imports System.IO
Imports System.Threading
[CODE]...........................
I cant get System.Threading.Thread.Sleep to work..[code]
View 2 RepliesWhen it comes to threading. I've managed to adapt one of JMcIllhinney's backgroundworker codebank examples to somewhat suit my needs, but not completely. I have a main form, and a second form that appears while I'm running through a for loop. It informs the user what is currently happening. I set up a backgroundworker that allowed me to continue to use the main form during the for loop, but the other "status" form was completely frozen, and any labels or graphics were shown as white boxes. I am struggling to figure out how to be able to move/interact with both forms while the loop is running.
View 4 RepliesThe coding that I have a problem with might make people think that I am creating some malware. So the project I am doing is associated with iTunes. iTunes allows people to have one library. There is another way, but it is very confusing to some people, and very unreliable. So my project is that I will allow people to have multiple iTunes libraries on one computer. So the problem is this. In order to have an option to choose your library, I gotta make sure that iTunes is not running.
So this is the script:
Private Sub CheckAndCloseiTunes()
retry:
'Custom class that includes the function to safely close iTunes
Dim Processes As Process() = Process.GetProcessesByName("iTunes")
[CODE]...
So when I use the Threading.Thread.Sleep(2000) code, the form becomes unresponsive.