Event For The Termination Of A Thread And Process?
Jul 12, 2009
At the moment, I am writing a class that deals with starting an application in a thread, as well as being able to monitor the closure of the thread and process, and the creation of the thread and process through events. I have absoloutly no problems with monitering the creation of the thread and its internal process within the subs that create them. I placed notifications within the "myprocess_Exited",(for the process closure) and "myprocess_Disposed"(for the thread closure) events.
The problem comes when I terminate the outside application manually; these events do not appear to fire when the application is closed by the user, rather than by code.I thought, since the application closes with an error code when it is terminated in such a way, that it raises the "myprocess_ErrorDataRecieved" event. But this doesn't appear to happen either. Here is some of the code from that class:
'Some of the decleratoins
Event ProcessStarted(ByVal Process As Process)
Event ThreadStarted(ByVal Thread As System.Threading.Thread)
I am making a function of an application that when a function is called the application will close all processes that are owned by the user and were started after a specific point. My thoughts on this would be to trigger an event in my application every time a process is started and ended, and only if the processes is owned by the user, the event should get information (e.g. the process ID, name, etc) about that process and add or remove that information to/from an array depending on if the process starts or ends. Then when a function is called end all the processes in that array.
how do I force a particular set of vb.net codes to run in a new thread or process.? Edit 1: I am trying TTS in vb.net but whenever click the play button , The whole program freezes and I cannot do anything else until the speech is over
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 [Code] .....
Here's the problem I am trying to solve. My program can export a file as a pdf. and other formats. I can open the file using process.start. My file doesnt have a good name so I am using a GUID as a name.
Basically, I am just trying to close the thread/process after it's done.
Private psi As ProcessStartInfo Private cmd As Process Public Delegate Sub InvokeWithString(ByVal text As String) Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim psi As New ProcessStartInfo("m7.bat") [Code] .....
I am trying to close the thread so once it's done, it closed for good and my form is closed as well. I tried Me.Close() which results in: "Cross-thread operation not valid: Control 'Form1' accessed from a thread other than the thread it was created on." Error.
Me.Invoke(New InvokeWithString(AddressOf CloseME), e) - Results in parameter mismatch error. However, things like Msgbox("Done") works perfectly.
I would like to implement a mulithtreaded crawler using the single thread crawler code I have now. Basically I read the urls from a text file, take each one and crawl and parse it. I know how thread basics of creating a thread and assigning a process to it but not too sure how to implement in the following way:
I need at least 3 threads and need to assign a url to each thread from a list of urls, and then each needs to go and fetch it and parse it before adding contents to a database. [Code] Now the code maynot make sense but what I need to do is add a unique url to each thread to go process.
I have two applications. For performing certain functions, i run a second exe, via a process, and wait till it is complete (exited) to continue with my main application. I run through many repetitive functions on different files.Everything runs fine however, when i am doing a run and it is on the x loop number, the main application seems to halt the secondary process exe. I can only assume this is what is happening as, if i close/stop (not pause) my main application in VB, the second exe continues from where it was halted until it completes.
I have an application which I wrote in vb.net. When the application starts it connects to mysql database online to get some data and once done it proceeds.The problem is that at times it gets stuck in the mysql thing, I mean after requesting nothing happens and this causes my program to lock up. This can be because of internet problem or server.
Is there a way the program can determine that x seconds has elapsed and it has not got any data, so self terminate it. I tried using timer to perform this action but as the program requests for data, it gets stuck, I mean it locks up and thus timer also locks up and only after task is done everything resumes.
I wanted that when the program is about to start request, I can start a timer and determine that x seconds has elapsed, so now terminate the application.
A long time ago, on a PC far, far away from Windows, one MS-DOS program (the father) could run / execute / spawn another MS-DOS program (the son). When the son terminated, it could set a return code which could certainly be interrogated by an MS-DOS batch program or, I think, by any father program that invoked it (depending on the language in which that program was written). I have a small utilility which I want to invoke from my application, and, since that utility sets a return code, I would like to interrogate it in my application when the utility terminates. I've looked through the MSDN Library but could not find anything that seemed to cover this situation. Is there a way to do this in Visual Basic 2008 Express
I'm currently having a form that has a button starting a long process, with feedback into another windows textbox (call frmProcessLog).
I'm using a Background worker to laucnh the process, upgrade the status of the process and display feedback on the frmProcessLog textbox, and to know when the thread process ended up, (from the cancel button, from an error or normal termination).
the main thread process has some msgbox in it, asking questions to the operator (yes/no/cancel).
I've added the msgboxstyle.systemmodal to the msgbox call which works "ok" excpet if the operator decide to ignore the showing message box and click the cancel button on the frmProcessLog form, which is still clickable even though I supplied "systemModal" to the msgbox. this makes the msgbox hidden behind the frmProcesslog form and the process can still continue.
If I close my frmProcessLog form, I will see the previously msgbox behind it and If I end up click one of the button it will end up at an application error because the thread that called it is not existing anymore.
So I would like that the msgbox to be launched from the thread making it as if it was launched from my frmProcessLog window in a modal way.
It is my previous problem in vb6, its hard to multithread using vb6 so I migrate my codes to vb.Net.How can I multithread this two loops so that this process is running at the same time.Because when I start my second Loop, my first loop stop in executing. It will start again when my 2nd loop finished.
I have 2 connected GSM Modem in usb port.That codes will send SMS in all contacts in my ListBox.
I just wanted to know that When our Vb.net application terminates are all our foreground threads automatically terminated.I read that all our background threads (worker threads) are all automatically terminated once the application shutsdown (when we dispose it)H/owever i wanted to know about Foreground threads , I know that wehn we use
dim t as thread t = new thread (address of blahblah) t.isbackground = true ; //This makes it a worker thread ... which will terminate when the form is disposed t.start()
my question is now suppose i dont set the background property and make it run as a foreground parallel thread. Will it close when the application disposes...
I have the need to either prevent, or restrict, the termination of a VB.Net application. I have no problem with Admin killing the application, but not a user. I've been unable to come up with a solution for this. Is there maybe even a way to set local policy to prevent termination by non-admin?
I tried raise an event from another thread, but various error about classes and so on. I try to avoid classes.
Error 1 Cannot refer to an instance member of a class from within a shared method or shared member initializer without an explicit instance of the class. C:Documents and SettingsLMMy DocumentsVisual Studio 2008Projectssarja4bWindowsApplication2formsForm1_saielyhyt.vb 179 32 sarja4b
I am using VB2008
I used threads because I wanted to test and play with them. Threads worked I think, but now I wonder what is wrong with events?
SerialPort1.DataReceived seems to suit better here, but why don't my events work?
Here is skeleton of my code
Imports System Imports System.IO.Ports Imports System.Threading
I'd like to create a WebBrowser for the purpose of taking a screenshot of a website. Once its finished it will update a thumbnail image in a ListView. I'd like the whole operation to be done in the background so the UI remains responsive.I toyed with Creating the WebBrowser in a new thread and calling Navigate. I can use a loop to watch for the ReadyState of the webbrowser before I do the screencapture. However it will only continue with the thread if I use Application.DoEvents in that loop. I've never been a huge fan of doing this and would prefer to watch for an event instead. However if I add a handles clause to the WebBrowser it doesn't fire (I tried creating the WebBrowser in the thread, and also tried by declaring it as shared within the class scope).
I have a small form that notifies the user on the completion of events (such as SMO restore). I want this form to appear from various sources (such as the below SMO Restore complete event) so I guess I need to create a new thread before creating the form? As it could be called from outside the UI thread. (I also need to pass a string to this form)
(I don't believe the reason for this is relevant, but just in case: I'll be raising events from code within a form's WndProc sub. If the code handling the event blocks with something on a form [such as a msgbox], then all sorts of trouble occurs with disconnected contexts and what not. I've confirmed that raising events on new threads fixing the problem.)[code]...
I am trying to use a separate thread to handle specific events in VB.Net. The idea being that I do not want the main application to be held up if a particular event handler takes awhile to finish. How do I get my main thread loop to suspend the thread while allowing it to handle events when they occur?When I create a Windows Forms application, there is a UI thread that handles the UI events. I do not imagine that this thread is continuously polling some variable to see if someone has pressed a button. I imagine the thread is suspended until the OS tells it there is something to do. I was trying to figure out how to ensure that my event handlers were not being executed by the UI thread. From what I have read, I can do this by raising the events from a different thread. But what does that thread do while it is waiting for other events, just exit?
I wanted to know how to create a thread that works like the UI thread, only it processes the events I want it to process. I am not sure how events work in .Net. I understand that event handlers are run on the thread that raises the event. I believe that .Net allocates threads from some thread pool to process events such as timer events. I am not clear on how it works, though, and what those threads are doing when they are not handling events.
I am working on a client/server based application and I have run into quite a few snags stumbling my way through I have resolved quite a few issues, and need help with something new. I am using a TCPIP client/server and I find that at the end of each loop when I am reading the data from the network stream it appends a character to the end. I have tried removing the last character but I am not sure if it is getting the whole character successfully because I still get lots of different errors both in binary and xml deserialization whcih I think is related to this. Does anyone know the ascii code for the termination character for TCPServer/Client communications?
In 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()
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".
"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.
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
I have a processing in a do loop. In variois points within the loop I check if the variable "bCancel" is true. If so then I exit the loop and terminate the treatment. When I click the "Cancel" button, I set the variable "bCancel" to true. Basic stuff, but I would like to know how the click event is ran while my current thread is busy looping? I've found a reference to a "Gui thread" on the net but Its not very clear is this thread in inside windows or the .NET frameworks?
I actually have gotten the events firing like I expect except for trying to close the dialog window.
Background: I have a wrapper around my "Jabber Client" that sets the delegates for the client wrapper and basically generates a messageProcess event. This event is wired in the main program Class[code]...
I'm developing some code to detect new files in a directory and signal it in a new thread through the Created event of FileSystemWatcher. While testing this I noticed that after I removed the eventhandler from the event the thread that was being used was not closed. Why is that? Am I doing something wrong when I'm removing the eventhandler? [code]So first I start off clicking Button 2 to start the event handler. I copy a xml file to the Temp folder and the event will trigger and set the name of the thread. After that I will click Button 1 to remove the event handler. If I then pause the execution the Thread "UpdateSomething" will still be there.
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.
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:
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