Determine if Timer is running - c#

In this Link it shows how to determine if a timer is running. For me it is not working.
I have the timer declared in a static class as shown
public static class ServiceGlobals // Globals
{
public static System.Timers.Timer _timer = new System.Timers.Timer();
}
}
On Start-up of my service, I set the timer properties
protected override void OnStart(string[] args)
{
ServiceGlobals._timer.AutoReset = false;
ServiceGlobals._timer.Interval = (3000);
ServiceGlobals._timer.Elapsed += new System.Timers.ElapsedEventHandler(_timer_Elapsed);
ServiceGlobals._timer.Enabled = true;
ServiceGlobals._timer.Start(); // Start timer
}
then i check if it is running in one of my methods but even when it is running the code is always false
if (ServiceGlobals._timer.Enabled) // Check if the timer is running
{
// Return error.........
}

You must have missed this part of the thread you linked:
"If Timer.AutoReset is true, then Enabled will automatically be set to false the first time the timer expires."

Related

System.timer doesnt throw events and console terminates immediatly

I need a timer that executes every minute but i have trouble getting the timer to run at all with code that i used before. so i guess i am doing sth fundamentally wrong that is not code related but even in a just newly created Console project in visual studio community 2017 it doesn't execute the _timer_elapsed method. the console terminates immediately without errors as if it has executed every code
using System;
using System.Timers;
namespace Test
{
class Program
{
static Timer _timer;
public static void Main(string[] args)
{
var timer = new Timer(60000);
timer.Elapsed += new ElapsedEventHandler(_timer_Elapsed);
timer.Enabled = true;
_timer = timer;
}
static void _timer_Elapsed(object sender, ElapsedEventArgs e)
{
Console.WriteLine("test");
}
}
}
what am I missing here?
You need your program to stay alive, rather than return from Main. An quick and easy way to do this is to wait for some input at the end:
public static void Main(string[] args)
{
var timer = new Timer(60000);
timer.Elapsed += new ElapsedEventHandler(_timer_Elapsed);
timer.Enabled = true;
_timer = timer;
Console.ReadLine();
}
There is no such thing as a bad question.
(Though some questions show more affinity with programming, and some show less.)
If you look at your code, your main sets up a timer and then proceeds to terminate. So, of course your program exits immediately and the timer is never fired.
In order to see your timer firing, your program will need to keep running for at least as long as one period of your timer.

How to start method on timer from windows service?

I have a method that executes in about 10 minutes. And it goes well just by itself. I need to start this method every hour using windows service (this is obligatory). So I've written my service by some examples (just one invoke for start):
partial class ServiceWSDRun : ServiceBase
{
protected override void OnStart(string[] args)
{
Thread t = new Thread(WebServiceDownload.MainProgram.Execute);
t.Start();
}
}
Now when I install it, it launches my method in a new thread but this thread seem to end with the OnStart() - it actually logs some info from the beginning of me method. Why does it stop and what should I do?
And I'm thinking in the end I should have something like this:
partial class ServiceWSDRun : ServiceBase
{
System.Timers.Timer timer = null;
protected override void OnStart(string[] args)
{
Thread t = new Thread(WebServiceDownload.MainProgram.Execute);
t.Start();
timer = new System.Timers.Timer();
timer.Interval = 60 * 60 * 1000; // 1 hour
timer.Elapsed += new System.Timers.ElapsedEventHandler(OnTimer);
timer.Enabled = true;
}
public void OnTimer(object sender, System.Timers.ElapsedEventArgs args)
{
WebServiceDownload.MainProgram.Execute();
}
protected override void OnStop()
{
timer.Enabled = false;
}
}
How do I make it work? And keep in mind that method takes ~10 mins to execute.
You should use System.Threading.Timer instead of System.Timers.Timer.
Here is the reference for this:
https://msdn.microsoft.com/en-us/library/system.threading.timer(v=vs.110).aspx
Also, another thread about the same topic:
System.Timers.Timer vs System.Threading.Timer
You should lock the execution, avoiding the second execution before the first one finishes.

DispatcherTimer keeps firing after I've stopped it. C# UWP

I'm having trouble with the following code. I have some code that calls SetTimer() and expects the user to respond before interval is reached (in
millisecs). The calling code inherit these funtions. If the user responds, then StopTimer() is called, info is displayed, StartTimer() is called, and the user is expected to respond again within the interval time period. This continues until the user fails in an answer or takes too long (goes past the interval).
The problem is the timers don't stop. They keep repeating even after I've stopped them, set their Tick event to null (by the -= method), and left its scope. I even get new storage with a new DispatcherTimer (I've done this both using the old one and a new one each time). I can't get the old Timer to go away.
What am I doing wrong?
using Windows.UI.XAML;
public DispatcherTimer GameTimer;
internal void SetTimer(int interval)
{
GameTimer = new DispatcherTimer();
GameTimer.Tick += TimerCallback;
GameTimer.Interval = new TimeSpan(0,0,0,0,interval);
GameTimer.Start();
}
internal void StopTimer()
{
GameTimer.Stop();
try
{
GameTimer.Tick -= TimerCallback;
} catch {}
}
private void TimerCallback(object sender, object e)
{
StopTimer();
// Other code
}
Thanks in advance,
-justin
Try stopping the timer by using the sender object, not the actual public timer object:
private void TimerCallback(object sender, object e) {
(sender as DispatcherTimer).Stop();
// Other code
}
As a workaround, you could do something like:
// in your class
private bool _allowExecution = false;
Then whenever you start the time set _allowExecution = true; and when you stop the timer, simply add _allowExecution = false;
The last thing will be to add a simply boolean condition on your timer execute: if (_allowExecute) //do your stuff here
Because you initialize a new DispatcherTimer everytime call SetTimer(int interval). You must stop the old DispatcherTimer instance before initialize a new one.
internal void SetTimer(int interval)
{
StopTimer();
GameTimer = new DispatcherTimer();
GameTimer.Tick += TimerCallback;
GameTimer.Interval = new TimeSpan(0,0,0,0,interval);
GameTimer.Start();
}
internal void StopTimer()
{
if(GameTimer != null)
{
GameTimer.Stop();
GameTimer.Tick -= TimerCallback;
GameTimer = null;
}
}

How do I show text on a label for a specific time (like 3 seconds)?

I have a statusbar label and I want to show a text on my StatusBar Label for 3 seconds only
How can I do it without using threads?
public void InfoLabel(string value)
{
if (InvokeRequired)
{
this.Invoke(new Action<string>(InfoLabel), new object[] { value });
return;
}
infoLabel.Text = value;
}
Simply add timer on the end of your method:
if (!string.IsNullOrWhiteSpace(value))
{
System.Timers.Timer timer = new System.Timers.Timer(3000) { Enabled = true };
timer.Elapsed += (sender, args) =>
{
this.InfoLabel(string.Empty);
timer.Dispose();
};
}
You need to define a function that you call each time you need to display your text, inside this function you define a timer, this timer is based on System.Windows.Forms.Timer, the only difference is that its modified to hold a stopTime parameter that represents the running duration, the only thing you need to do is to put your starting code(display text) inside the MyFunction function and to put the ending code(to stop displaying text) inside the Timer_Tick function, once you call MyFunction just specify how many seconds you want it to run in the function parameter.
private void MyFunction(int durationInSeconds)
{
MyTimer timer = new MyTimer();
timer.Tick += new EventHandler(Timer_Tick);
timer.Interval = (1000) * (1); // Timer will tick every second, you can change it if you want
timer.Enabled = true;
timer.stopTime = System.DateTime.Now.AddSeconds(durationInSeconds);
timer.Start();
//put your starting code here
}
private void Timer_Tick(object sender, EventArgs e)
{
MyTimer timer = (MyTimer)sender;
if (System.DateTime.Now >= timer.stopTime)
{
timer.Stop();
//put your ending code here
}
}
the modified timer class
public class MyTimer : System.Windows.Forms.Timer
{
public System.DateTime stopTime;
public MyTimer()
{
}
}
You can use Timer to create an instance of a timer that waits for n seconds before firing the Elapsed event. In the elapsed event, you clear the label's Content.
As the timer is executed in a separate thread, the UI thread is not locked while the timer is counting i.e. you are free to perform other operations in the UI.
private delegate void NoArgDelegate();
private void StartTimer(int durationInSeconds)
{
const int milliSecondsPerSecond = 1000;
var timer = new Timer(durationInSeconds * milliSecondsPerSecond);
timer.Start();
timer.Elapsed += timer_Elapsed;
}
private void timer_Elapsed(object sender, ElapsedEventArgs e)
{
var clearLabelTextDelegate = new NoArgDelegate(ClearLabelText);
this.Dispatcher.BeginInvoke(clearLabelTextDelegate);
}
private void ClearLabelText()
{
this.myLabel.Content = string.Empty;
}
As I do not the rest of your code, some suggestions would be to create a lock on the timer so as to prevent more than one UI event starting the timer. In addition, the delegate and the timer instance can be made as private members of the class.
You'll always be using at least the GUI thread. If you decide to wait on that thread, no other interaction with controls is possible (ie. no buttons will work, the window will not be repainted).
Alternatively you could use a System.Windows.Forms.Timer that gives control back to the OS, or another type of timer. Either way, the "countdown" will either block user interaction or happen on another thread (under the hood).

How to stop a timer after it is done running?

I have a Console App and in the main method, I have code like this:
Timer time = new Timer(seconds * 1000); //to milliseconds
time.Enabled = true;
time.Elapsed += new ElapsedEventHandler(time_Elapsed);
I only want the timer to run once so my idea is that I should stop the timer in the time_Elapsed method. However, since my timer exists in Main(), I can't access it.
You have access to the Timer inside of the timer_Elapsed method:
public void timer_Elapsed(object sender, ElapsedEventArgs e)
{
Timer timer = (Timer)sender; // Get the timer that fired the event
timer.Stop(); // Stop the timer that fired the event
}
The above method will stop whatever Timer fired the Event (in case you have multiple Timers using the same handler and you want each Timer to have the same behavior).
You could also set the behavior when you instantiate the Timer:
var timer = new Timer();
timer.AutoReset = false; // Don't reset the timer after the first fire
A little example app:
static void Main(string[] args)
{
int seconds = 2;
Timer time = new Timer(seconds * 1000); //to milliseconds
time.Enabled = true;
time.Elapsed += new ElapsedEventHandler(MyHandler);
time.Start();
Console.ReadKey();
}
private static void MyHandler(object e, ElapsedEventArgs args)
{
var timer = (Timer) e;
timer.Stop();
}
I assume that you're using System.Timers.Timer rather than System.Windows.Forms.Timer?
You have two options.
First, as probably the best, is to set the AutoReset property to false. This should do exactly what you want.
time.AutoReset = false;
The other option is to call Stop in the event handler.
You may also use the System.Threading.Timer. Its constructor takes two time-related parameters:
The delay before the first "tick" (due time)
The period
Set the period to Timeout.Infinite to prevent from firing again.

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