Develop Reference

c# timer is going too fast if set

i'm trying to implement a simple countdown using Timer (using https://www.geoffstratton.com/cnet-countdown-timer code). it does work if i run the timer once but if i stop the timer or the timer goes to 00:00 the next time i'll start it, it will go 2x faster. if i stop it and start it again it will go 3x faster.
(my explaination may be not clear, i did a gif that demonstrate the problem)
https://media.giphy.com/media/fQr7sX6LNRECvQpCYP/giphy.gif
i'm very novice at c#, i usually figure things out but i cant get what's happening here.
I included the timer code. if somebody can help me with this it would be awesome!
Thanks !!!
private void btnStartTimer_Click(object sender, EventArgs e)
{
if (txtTimer.Text == "00:00")
{
MessageBox.Show("Please enter the time to start!", "Enter the Time", MessageBoxButtons.OK);
}
else
{
string[] totalSeconds = txtTimer.Text.Split(':');
int minutes = Convert.ToInt32(totalSeconds[0]);
int seconds = Convert.ToInt32(totalSeconds[1]);
timeLeft = (minutes * 60) + seconds;
btnStartTimer.Enabled = false;
btnCleartimer.Enabled = false;
txtTimer.ReadOnly = true;
timer1.Tick += new EventHandler(timer1_Tick);
timer1.Start();
}
}
private void btnStopTimer_Click(object sender, EventArgs e)
{
timer1.Stop();
timeLeft = 0;
btnStartTimer.Enabled = true;
btnCleartimer.Enabled = true;
txtTimer.ReadOnly = false;
}
private void btnCleartimer_Click(object sender, EventArgs e)
{
txtTimer.Text = "00:00";
}
private void timer1_Tick(object sender, EventArgs e)
{
if (timeLeft > 0)
{
timeLeft = timeLeft - 1;
// Display time remaining as mm:ss
var timespan = TimeSpan.FromSeconds(timeLeft);
txtTimer.Text = timespan.ToString(#"mm\:ss");
// Alternate method
//int secondsLeft = timeLeft % 60;
//int minutesLeft = timeLeft / 60;
}
else
{
timer1.Stop();
SystemSounds.Exclamation.Play();
MessageBox.Show("Time's up!", "Time has elapsed", MessageBoxButtons.OK);
}
}

You need to unsubscribe from the event in your btnStopTimer_Click method:
timer1.Tick -= timer1_Tick;

You are adding the event to Count every time you start the timer. As a result, the first time you call it there is only one event, the second time two events and so on. As a result, you first go down one second, then two,....
I would recommend creating the timer separately and just call Start and Stop.
Alternativ, user Dmitry Korolev answered a good Approach if you don't want to create the timer somewhere else
timer1.Tick -= timer1_Tick;

Check if the countdown timer is 0

I have a script based on the countdown timer. I want that when the time reaches 0, the timer stop and a message appear. The code id this:
public partial class simulare : Form
{
private admin admin;
Timer timer = new Timer();
public simulare(admin admin)
{
InitializeComponent();
this.admin=admin;
label2.Text = TimeSpan.FromMinutes(0.1).ToString();
}
private void simulare_Load(object sender, EventArgs e)
{
var startTime = DateTime.Now;
timer = new Timer() { Interval = 1000 };
timer.Tick += (obj, args) =>
label2.Text = (TimeSpan.FromMinutes(0.1) - (DateTime.Now - startTime)).ToString("hh\\:mm\\:ss");
timer.Enabled = true;
timer.Start();
if (condition)
{
timer.Stop();
MessageBox.Show("Done!");
}
}
}
I tried those conditions, but unsuccessful:
if (timer.ToString() == TimeSpan.Zero.ToString())
if (label2.Text.ToString() == TimeSpan.Zero.ToString())
if (label2.Text == TimeSpan.Zero)

You could extract the calculation and assign the result to a TimeSpan variable, then check if the Seconds in that TimeSpan variable are equals to zero
void simulare_Load(object sender, EventArgs e)
{
var startTime = DateTime.Now;
timer = new System.Windows.Forms.Timer() { Interval = 1000 };
timer.Tick += (obj, args) =>
{
TimeSpan ts = TimeSpan.FromMinutes(0.1) - (DateTime.Now - startTime);
label1.Text = ts.ToString("hh\\:mm\\:ss");
if (ts.Seconds == 0)
{
timer.Stop();
MessageBox.Show("Done!");
}
};
timer.Start();
}

First off, checking anything in the Load event isn't going to work. That code only runs once (on form load).
So you need a more complex tick event, which I would put into an actual function instead of a lambda:
private int countDown = 50; //Or initialize at load time, or whatever
public void TimerTick(...)
{
label2.Text = (TimeSpan.FromMinutes(0.1) - (DateTime.Now - startTime)).ToString("hh\\:mm\\:ss");
countDown--;
if (countDown <= 0)
timer.Stop();
}
I use an int counter here since checking against a view property (the text in this case) isn't a very good design/practice. If you really want a TimeSpan, I would still save it off instead of checking directly against the Text property or a string.

Timer to close the application

How to make a timer which forces the application to close at a specified time in C#? I have something like this:
void myTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
if (++counter == 120)
this.Close();
}
But in this case, the application will be closed in 120 sec after the timer has ran. And I need a timer, which will close the application for example at 23:00:00. Any suggestions?

The first problem you have to fix is that a System.Timers.Timer won't work. It runs the Elapsed event handler on a thread-pool thread, such a thread cannot call the Close method of a Form or Window. The simple workaround is to use a synchronous timer, either a System.Windows.Forms.Timer or a DispatcherTimer, it isn't clear from the question which one applies.
The only other thing you have to do is to calculate the Interval property value for the timer. That's fairly straight-forward DateTime arithmetic. If you always want the window to close at, say, 11 o'clock in the evening then write code like this:
public Form1() {
InitializeComponent();
DateTime now = DateTime.Now; // avoid race
DateTime when = new DateTime(now.Year, now.Month, now.Day, 23, 0, 0);
if (now > when) when = when.AddDays(1);
timer1.Interval = (int)((when - now).TotalMilliseconds);
timer1.Start();
}
private void timer1_Tick(object sender, EventArgs e) {
this.Close();
}

I'm assuming you're talking about Windows Forms here. Then this might work (EDIT Changed the code so this.Invoke is used, as we're talking about a multi-threaded timer here):
void myTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
if (DateTime.Now.Hour >= 23)
this.Invoke((Action)delegate() { Close(); });
}
If you switch to using the Windows Forms Timer, then this code will work as expected:
void myTimer_Elapsed(object sender, EventArgs e)
{
if (DateTime.Now.Hour >= 23)
Close();
}

If I understand your request, it seems a little wasteful to have a timer check the time every second, where you can do something like this:
void Main()
{
//If the calling context is important (for example in GUI applications)
//you'd might want to save the Synchronization Context
//for example: context = SynchronizationContext.Current
//and use if in the lambda below e.g. s => context.Post(s => this.Close(), null)
var timer = new System.Threading.Timer(
s => this.Close(), null, CalcMsToHour(23, 00, 00), Timeout.Infinite);
}
int CalcMsToHour(int hour, int minute, int second)
{
var now = DateTime.Now;
var due = new DateTime(now.Year, now.Month, now.Day, hour, minute, second);
if (now > due)
due.AddDays(1);
var ms = (due - now).TotalMilliseconds;
return (int)ms;
}

You may want to get the current system time. Then, see if the current time matches the time you would like your application to close at. This can be done using DateTime which represents an instant in time.
Example
public Form1()
{
InitializeComponent();
Timer timer1 = new Timer(); //Initialize a new Timer of name timer1
timer1.Tick += new EventHandler(timer1_Tick); //Link the Tick event with timer1_Tick
timer1.Start(); //Start the timer
}
private void timer1_Tick(object sender, EventArgs e)
{
if (DateTime.Now.Hour == 23 && DateTime.Now.Minute == 00 && DateTime.Now.Second == 00) //Continue if the current time is 23:00:00
{
Application.Exit(); //Close the whole application
//this.Close(); //Close this form only
}
}
Thanks,
I hope you find this helpful :)

void myTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
if (DateTime.Now.Hour >= 23)
{
this.Close();
}
}

Task.Delay(9000).ContinueWith(_ =>
{
this.Dispatcher.Invoke((Action)(() =>
{
this.Close();
}));
}
);

Set up your timer to check every second like now, but swap the contents with:
void myTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
if (DateTime.Now.Hour == 23)
this.Close();
}
This will make sure that when the timer run and the clock is 23:xx, then the application will shut down.

How to use same timer for different time intervals?

I am using a timer in my code. Status bar updates in tick event on clicking respective button for the time inteval mentioned in properties say one second. Now i want to use the same timer for a different time interval say two seconds for a different oepration. How to achieve that?

Create a second timer. There is nothing to gain from hacking the first timer.
As #Henk noted, Timers are not that expensive. (Especially not compared to fixing hard to maintain code!)

I agree with #Henk and others.
But still, something like this could work:
Example
Int32 counter = 0;
private void timer1_Tick(object sender, EventArgs e)
{
if (counter % 1 == 0)
{
OnOneSecond();
}
if (counter % 2 == 0)
{
OnTwoSecond();
})
counter++;
}
Updated Example
private void Form_Load()
{
timer1.Interval = 1000; // 1 second
timer1.Start(); // This will raise Tick event after 1 second
OnTick(); // So, call Tick event explicitly when we start timer
}
Int32 counter = 0;
private void timer1_Tick(object sender, EventArgs e)
{
OnTick();
}
private void OnTick()
{
if (counter % 1 == 0)
{
OnOneSecond();
}
if (counter % 2 == 0)
{
OnTwoSecond();
}
counter++;
}

Change timer Interval property.

Change the Interval property in every elapsed time. for example, this program process data 30 seconds and sleep 10 seconds.
static class Program
{
private System.Timers.Timer _sleepTimer;
private bool _isSleeping = false;
private int _processTime;
private int _noProcessTime;
static void Main()
{
_processTime = 30000; //30 seconds
_noProcessTime = 10000; //10 seconds
this._sleepTimer = new System.Timers.Timer();
this._sleepTimer.Interval = _processTime;
this._sleepTimer.Elapsed += new System.Timers.ElapsedEventHandler(sleepTimer_Elapsed);
ProcessTimer();
this._sleepTimer.Start();
}
private void sleepTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
ProcessTimer();
}
private void ProcessTimer()
{
_sleepTimer.Enabled = false;
_isSleeping = !_isSleeping;
if (_isSleeping)
{
_sleepTimer.Interval = _processTime;
//process data HERE on new thread;
}
else
{
_sleepTimer.Interval = _noProcessTime;
//wait fired thread and sleep
Task.WaitAll(this.Tasks.ToArray());
}
_sleepTimer.Enabled = true;
}
}

C# - Countdown Timer Using NumericUpDown as Interval

I'm sure this has been asked before, but I cannot seem to find a solution that works. I have a NumericUpDown on my form and a label along with a timer and a button. I want the timer to start when the button is pressed and the interval for the timer to equal that of the NumericUpDown and a countdown will be displayed in the label. I know this should be easy. Any help?
So far:
int tik = Convert.ToInt32(TimerInterval.Value);
if (tik >= 0)
{
TimerCount.Text = (tik--).ToString();
}
else
{
TimerCount.Text = "Out of Time";
}
It doesn't seem to update as the timer ticks.

Here is a quick example to what you are looking for. This should give you a basic idea on what you need to do
//class variable
private int totNumOfSec;
//set the event for the tick
//and the interval each second
timer1.Tick += new EventHandler(timer1_Tick);
timer1.Interval = 1000;
private void button1_Click(object sender, EventArgs e)
{
totNumOfSec = (int)this.numericUpDown1.Value;
timer1.Start();
}
void timer1_Tick(object sender, EventArgs e)
{
//check the timer tick
totNumOfSec--;
if (totNumOfSec == 0)
{
//do capture
MessageBox.Show("Captured");
timer1.Stop();
}
else
label1.Text = "Caputring in " + totNumOfSec.ToString();
}