I'm trying to invoke the below but the EventHander is not compatible with the RasConnectionEventArgs from my calling event, how would I invoke SetOverlayIcon and my notification icon on the UI thread?
Public Sub watcher_Connected(ByVal sender As Object, ByVal e As RasConnectionEventArgs)
If InvokeRequired Then
BeginInvoke(New EventHandler(AddressOf OnRegChanged))
[code]....
We have a UI with a progressbar. I know how to invoke, safely, the control from which it was not created from a thread. there are threads being processed in a threadpool, all of which calls an "agent" (which is a notifier to raise an event back to the UI to then increase the progressbar). an "agent" is set as a property in a State object, which is then passed into a method which will be executed on the ThreadPool. so, I invoke on the UI the method to update the progressbar, but the bar does not seem to update at all (screen frozen) and it takes a very very long time for it to execute. without threading, no problem.
[Code]...
i like my application to start and goto system tray from begining from where i show or hide my main application form. To implement this i create 1 form named "FRM_main" and 1 Class named "MainClass" then define a procedure in MainClass which is as follow.
[code]Public Shared Sub Main()
Dim FRM_main As Form = New Form
FRM_main.Show()
End Sub[/code]
and set Title, Size and location of form at design time.but i didn't get the desired result. my application didn't start and goto system tray as inteded.i also try coding the FormLoad Event to ME.Hide but it also doesn't work so how do i do this?
I m providing minimize to system tray feature in my application. For that I used Noticifation Icon. I used the followed snippet to show the Notification Icon Tooltip for 5 sec
Call NotificationIcon1.ShowBalloonTip(5000)
I have developed a program using vb.net 2008 that will allow you to open another program at a specific time. This is just a beta and that is why 2 way of telling the program when to close the program that opened and this program.Anyway this is my issue when I get everything set up to open the program once it opens i don't have focus on the main form or the notification icon. (When the program has not lauched the program I am able to use the notication icon. (notification icon does the follow: restores the main window to normal view and exits the program.) Could some help to get the notification icon to work when the program has launched.[code]
View 6 RepliesIn my notification area on my taskbar I always see pop up messages from programs. How do i do this, when I add notifyicon to my form it just put the icon there but no pop up message of my choice.
View 3 RepliesIn other alarm clocks I've seen, when you exit them, they close but minimize to a notification icon. I want to get that, but I don't know how. I've tried: Private Sub Form1_FormClosing(ByVal sender As System.Object, ByVal e As
[Code]...
I am trying to place a custom icon in a tray notification balloon, such as when you install updates from Windows Update, it shows a balloon in the tray with a custom icon.
How can I do this in VB.net?
How do I can put a text (shift the icon image) on notification icon alredy put it on system tray (near clock place) using Visual Basic 2010?
View 3 RepliesAt the moment, my project has a method
do_quote(quoteid,userid)
This method take a minute or two, and then redirects to another page.
This has been rewritten so that it now runs in the background and redirects to another page whilst the thread which do_quote is on continues. - This works fine.[code]...
What i would like is to send a notification to the browser when do_quote finishes. Ideally i'd like to change the text of a div on the masterpage(but just returning an ALERT javascript msgbox would be a start).
As far as i understand, Callback is called at the end of the process, so i think this would be an ideal place to send javascript to the browser, but i can't think how i could implement this. Does anyone have any ideas on how i could implement a very basic notification (msgbox, response.write etc.) to the browser when the Callback method is called at the end of the process?
I want to find the application thread and invoke something on it ... the problem is i have access to NO OBJECTS on the main thread so calling object.invoke is not an option. This is because I am making a plugin for something and have no access to the existing objects on the main thread .
View 4 Repliesi got a background worker that has the following code in the do work.... one of the things i want to do is to add rows if theres none available ...but i got an error saying i need to do a safe call thread...i already read about it but im stuck i put control.invoke, but that gives me an error too saying Error 1 Reference to a non-shared member requires an object reference.
[Code]...
I am making use of a serial port in a class. I am raising an event from that class to my form calling the class. Event contains data received... I wish to simply populate a textbox from the raised event.Now I am not specifically creating a seperate thread, but I get the normal crossthreading error when trying to update my textbox on the UI, so my assumption is that the serial port and its internal methods probably creates its own threads...Regardless, I am a bit confused as to how to properly implement an invoke, from my main form, pointing to the thread in the instantiated class...
Dim WithEvents tmpRS232 As New clsRS232
Private Sub but_txt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles but_txt.Click
tmpRS232.Set_com_port("COM8", 38400)
[code]....
What is the Invoke syntax to marshall data from a background thread receive callback method to a function on the UI Thread?(Form1).
Public Class Form1
MyDelegate = New DisplayData(AddressOf DisplayData)
Private Sub Form1_Load()
MyDelegate = New DisplayData(AddressOf DisplayData)
[code]....
I Have a Function on my frmMain Class wich will update my control to something else after an invoke. When i type "?Label1.Text" on the Immediate Window, the text property IS updated, but when i go check the Form, nothing happened. The code is just like this
[Code]...
i got a background worker that has the following code in the do work.... one of the things i want to do is to add rows if theres none available ...but i got an error saying i need to do a safe call thread...i already read about it but im stuck i put control.invoke, but that gives me an error too saying Error1Reference to a non-shared member requires an object reference.what can i do to add rows safely?
vb.net
Private Sub BackgroundWorker2_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker2.DoWork
If DataGridView2.Rows.Item(num).Cells.Item(0).Value = "" Then
Control.Invoke(DataGridView2.Rows.Add(1))
CODE:
Is there anything I need to change about this code to let me insert list items to a listbox on the UI thread?
I have created a class for Socket reads so I can create sockets on command. Due to performing a socket read, the program will freeze waiting for incoming data due to being on a single thread. So I created a separate thread for the reading of the sock and attempt to invoke an event to prevent multi-threading errors.
But I am getting an error when trying to Invoke: "Invoke or BeginInvoke cannot be called on a control until the window handle has been created."
How can I fix this or is there a better way to read a sock without freezing the thread?
Class for Sockets:
Option Explicit On
Option Strict On
Imports System.Text
[CODE]...
Calling form code example:
Private WithEvents Socks As clsSock
Private Sub Sock_Connected(ByVal state As String) Handles Socks.Connected
MsgBox("Connected - " & state)
[CODE]...
I've got the following code:
[code]...
The problem is that, when I call the "SetStatusBarText" sub from another thread, InvokeRequired is True (as it should be), but then my threads stall on the Me.Invoke statement - pausing execution shows them all just sitting there, not actually invoking anything.
In my VB.net Winforms application I'm using the ITaskbarList3::SetOverlayIcon interface to set status overlays on the application's taskbar button (under Windows 7). This all seems to work fine for me, with the icons being shown and removed correctly.From the form load event, one of my functions makes the callSetOverlayIcon(parentForm.Handle, IntPtr.Zero, String.Empty)(where parentForm is the form which the load event has fired for) which very occasionally (on other people's machines) throws the following exception:
System.Runtime.InteropServices.COMException (0x8007057A): Invalid cursor handle. (Exception from HRESULT: 0x8007057A)
at MyNamespace.TaskbarNotify.ITaskbarList3.SetOverlayIcon(IntPtr hwnd, IntPtr hIcon,
[code].....
Why does SetOverlayIcon throw an 'Invalid cursor handle' COMException occasionally
View 1 RepliesI have a filesystewatcher object. On it`s event it runs a procedure which fills a treeview with a data. I had problems with treeview methods, but when I run them using invoke method everything is ok. But I still have one problem. When I load the form for the first time, everything works fine. But, when I then close the form (me.dispose, me.close), and load it once again, when Filesystemwathcer start the procedure i have an exception "invoke or begininvoke cannot be called on a control until the window handle has been created" trying to run a treeview.invoke method?
View 9 RepliesWhat is Platform Invoke Service (P/Invoke)?
View 1 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()
[code]....
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()
[code]....
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
[Code]...
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)
[CODE]...
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.