.net - Systems.timer.timer Unwanted Multithreading?
Jul 14, 2011
I recently switched my code from using the windows.forms.timer to the systems.timer.timer and it has resulted in a multithreading error. I'm using the timer to trigger just one event so multithreading shouldn't be an issue. To give more detail I have implemented the timer at follows:
At the top of the class I have: Private Shared timr1sec As System.Timers.Timer
When the program loads (Private Sub Test_load):
timr1sec = New System.Timers.Timer(1000)
AddHandler timr1sec.Elapsed, AddressOf OnTimedEvent
In OnTimedEvent I call several subroutines, and write some data to the screen using a ListView object.VisualExpress throws the multithreading error on the last line of this code, which is in OnTimedEvent
[Code]...
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May 12, 2010
I would like to close my program based on the system time. I have stuck a timer on my form and I want to set my timer to my systems time. if the timer = "8:00" pm or timer = 20:00 hrs then END Does any one have the code on this? If I could do it without the timer as in to check the systems time = 8:00 pm or 20:00 hrs then End
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Mar 1, 2011
I have a screen that checks for alerts every 30 seconds by looking up outstanding issues from a database.When there is an alert, an audio file is played depending on the alert.It takes 1-2 seconds to grab this audio file which caused an issue with global screen freezing, so I added multithreading where it plays the sound file. This seemed to work fine.However I am new to multithreading and am not sure if I'm working with it efficiently..I have simply declared the sound-playing function as a thread at the top:[code]I am unsure if starting and aborting the thread is the right way to do it. However if I suspend or make the thread sleep I would have to determine whether it has been run before.
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Feb 29, 2012
I've got a vb app in .Net 4 that i'm working on. The app fires up dynamic threads to run some jobs. Each thread runs a certain job and within that thread, it performs a infinate loop. It needs to be this way, i can't have the thread and then begin again...
anyway.. i was using threading.thread.sleep in the loop to have the loop pause for a bit before running again. It seems that this is not a good way to go and not recommended. So i thought perhaps i could use a dynamic timer or something else to have the thread wait for say 30 seconds before running again. i was hoping someone could give me some direction and example code.[CODE...]
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Aug 2, 2010
What I need to do to make this code work for hours as well?[code]...
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Jan 15, 2009
I need an accurate timer to interface a Windows application to a piece of lab equipment.I used System.Timers.Timer() to create a timer that ticks every 10 msec, but this clock runs slow. For example 1000 ticks with an interval of 10 msec should take 10 wall-clock seconds, but it actually takes more like 20 wall-clock sec (on my PC). I am guessing this is because System.Timers.Timer() is an interval timer that is reset every time it elapses. Since it will always take some time between when the timer elapses and when it is reset (to another 10msec) the clock will run slow. This probably fine if the interval is large (seconds or minutes) but unacceptable for very short intervals.Is there a function on Windows that will trigger a procedure every time the system clock crosses a 10 msec (or whatever) boundary?
UPDATE: System.Timers.Timer() is extremely inaccurate for small intervals.I wrote a simple program that counted 10 seconds several ways:
Interval=1, Count=10000, Run time = 160 sec, msec per interval=16
Interval=10, Count=1000, Run time = 16 sec, msec per interval=15
Interval=100, Count=100, Run time = 11 sec, msec per interval=110
Interval=1000, Count=10, Run time = 10 sec, msec per interval=1000
It seems like System.Timers.Timer() cannot tick faster that about 15 msec, regardless of the interval setting.Note that none of these tests seemed to use any measurable CPU time, so the limit is not the CPU, just a .net limitation (bug?)For now I think I can live with an inaccurate timer that triggers a routine every 15 msec or so and the routine gets an accurate system time. Kinda strange, but...I also found a shareware product ZylTimer.NET that claims to be a much more accurate .net timer (resolution of 1-2 msec). This may be what I need. If there is one product there are likely others.
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Jul 9, 2009
I have a timer on a page in ASP.NET.
After a certain period of time elapses, I want to disable the timer.
I want to put a static variable in the timers tick event that will track how many seconds have elapsed.
My question is, will this work?
If user X and Y are viewing the page will they both have separate local static variables?
What is the best method of shutting down an ASP.NET timer after a certain elapsed time?
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Apr 23, 2009
I have a windows application that need to process som quite time consuming jobs. In my first try i did all processing under
the form thread. The result was bad response and update of the form due to the heavy jobs.To get around the problem with bad response from the form i created a new class "processing" where i put all the data processing. Then i instanciated a background worker where i in the "doWork" sub created a new instance of "processing".The "processing" class creates a timer from system.timer, and the timer drives the processing.On the Timer event Elapsed the timer starts a new thread from the thread pool.
My problem is now when i want to asynchronously close the background worker (with the corresponding function call what ever it is called ...) there is still a timer thread out there that causes exceptions for me.
1. How can i close my background worker and at the same time have the timer to be stopped?
2. Is there a way to synchronize the timer event so that the timer executes from the background worker thread?
3. Is there a better approach for me to adapt?
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Jan 11, 2011
I want to create an array of timer in vb.net. My problem is that how will i raise the tick event for a particular timer, say mytimer(x).tick and inside the tick event there is also a button, say mybutton(x) which changes location every interval. for example:
public class blah
dim mybuttons(20) as button
dim mytimer(20) as timer
private sub form_load(....) handles me.load
for x as integer = 0 to 20
[Code]...
i dont know what to do next, all i want is to pass the button mybuttons(x) to mytimer(x) tick event, in which their index number are the same. i want to create one timer per button. how to do that? please help me and post example codes. i've researched the net but i cant understand passing variables, addhandlers, etc. i'm just new to programming object oriented.
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Jul 4, 2011
How can I incorporate the timer so once a page loads the timer activates, waits a few seconds then I tell my program what to do next.I tried this code but it didnt work:
Timer1.Interval = 5000
Timer1.Enabled = True
Timer1.Start()
[code]....
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Sep 30, 2010
Everything is nice and dandy on my pc, then I compile, move it to its final destination and I doesn't work! At first I thought it was a OS problem, but both machines has win7, I then thought it was a compilation problem, installed visual studio on the other pc, recompiled still with no luck, then it dawned on me, may it be a problem of 32bit vs 64bit?The piece of code is this:[code]....
By the way is not a problem of mouse_event, is the timer that doesn't work
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Mar 24, 2009
I have a timer in vb.net and it's interval is 1000ms ,. i have placed in it's timer_tick event a code that will print screen the screen and save it to a database.The problem is when i click outside of the form, or loosing the focus of the mouse to the form containing that timer/printscreen, the timer stops. As a result the printscreen also stops.here are it's properties:
generate member = true
interval = 1000
modifiers = friend
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Aug 13, 2010
I have a routine which is controlled by a timer. It works perfectly. The problem is that now, I need to run this routine several times, so I need to start differents threads so that my program doesn't get hung up. I've been trying to start my timer inside a thread, but it doesn't work!
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Nov 6, 2009
VB6 create object of timer instead of timer control
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Apr 6, 2009
Is it possible to use a timer to delay code? For example:
[code]...
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Mar 15, 2009
I already created a button "enjoy button" that i want to move in a form when the "timer start button" is clicked.how do link the timer to the"timer start button" and make it move? this is what i tried so far..then am blank first
Quote:
Private Sub MainForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'Me.xTimer.Enabled = False
xTimer.Interval = 10[code].........
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Feb 24, 2011
In a vb 2010 project, I have 2 win forms: Form1 and Form2.
In the Form1 class there is a server-based timer: when the "elapsed event" fires, then I update the text of a Label1 on the Form2. A very simple code:
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Jun 14, 2012
Quick question - if I have a timer set to 5000 (5 seconds) and the code in the timer takes longer than 5 seconds to run because of sql stuff, will the timer wait until the code is done till it fires again?
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Jun 15, 2009
I'm wondering what exactly is the difference System.Timers.Timer and System.Windows.Forms.Timer???
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Oct 27, 2009
My timer pauses (sort of the display portion (label) of the timer indeed pauses, however when the timer is resumed it starts again, but not at the point where it was disabled. As an example. If I pause the timer at 10:00 and wait ten seconds when I hit resume it starts at 09:50, where it should resume at 10:00 or 09:59
Module Helper
Public SessionTime As String
Public Pause As Boolean = False[code].....
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Aug 18, 2011
In the good old days of VB6 you could not rely on the timer control to fire at exactly the specified interval. If your program was doing some intense processing the Timer_Tick event is pushed onto the stack and only when it gets to the instruction is it processed, which may be some seconds(?) later.
[Code]...
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Feb 14, 2010
We put a picturebox & timerwe have put 3pics in any drive ok
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Feb 8, 2009
just tell me some thing about the timer class
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Aug 25, 2010
How can I use timer in vb.net? I want to repeat a statement after every 5 seconds but timer event offers only timer_tick() and timer_disposed()
In which event I can write my required code?
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Aug 10, 2009
I have a label who's text is determined by looping through a listbox upon a click event. I would like to have a timer loop through the listbox (... to set the label's text) if the button is not pressed in time ('x' seconds).
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Feb 13, 2010
I wrote an application that have two timers, one of them (timer_poll) when the ticks event i change the enable to false in order to execute a code. this code writes an information in a COM, and after recieved the information from the COM from a Funtion I change the Enable property for the timer_poll to enable again but it have neve run again.the timer_poll_tick_1 does not start again, i activate a breckpoint, I can confirm that the timer_poll.enable=true because i put a button on the application that on its click event it shows me tha properties of the timer_poll, like this:
MsgBox(
CStr(timer_poll.Interval) + "|" + CStr(timer_poll.Enabled))
here is the code of the timer_poll_tick_1
Private Sub timer_poll_Tick_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles timer_poll.Tick
timer_poll.Enabled =
[code]....
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Jun 2, 2011
How can I add a timer in the listview that minuses 1 second at a time when the button starts click and stops when the stop button is clicked? Then save the remaining time in the database.[url]...
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Feb 19, 2010
how I can add a new timer through code, and also add the code that the timer executes when it ticks
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Oct 4, 2009
How would i moniter how long a user uses my program and when it reaches a hour it will close the program, but then the user will have to wait 24 hours before they can gain accesss to the form again perhaps open a msgbox that shows how long is left till it can be used I like.. [code]...
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Aug 17, 2009
how to get the ascii of a key press on a timer.
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