Develop Reference

Windows service stopped after a day

I have written a windows service that fetch some data from a database and perform some functions every minute. I have a timer setup in the initialize code segment.
public WindowsService()
{
InitializeComponent();
// Set up a timer that triggers every minute.
System.Timers.Timer timer1 = new System.Timers.Timer();
timer1.Interval = 60000; // 60 seconds
timer1.Elapsed += new System.Timers.ElapsedEventHandler(this.OnTimer);
timer1.Start();
}
private void OnTimer(object sender, EventArgs e)
{
//StartProcess();
}
After the deployment it worked without any issue. But when the date is changed to next day (eg:deployed on 29th June and the current date is 30th June), the scheduler is not performing. After I do a service restart manually, it performed as normal. What can be the issue with the timer?

I beleive your timer is getting garbage collected. Declare the timer variable outside of the function so it never goes out of scope.

Extend the timer duration while ticking

I have a windows form application with time input(in minutes) which fires a GUI application after the timer elapses. Initially I take the input from the user and set the time. Say, the user enters 45 mins. After 45 mins, my other GUI application is launched. Currently I'm using this:
Timer MyTimer = new Timer();
private void Form1_Load(object sender, EventArgs e)
{
MyTimer.Interval = 45mins // Input from user
MyTimer.Tick += new EventHandler(MyTimer_Tick);
MyTimer.Start();
}
private void MyTimer_Tick(object sender, EventArgs e)
{
//pop my GUI application
}
so now, my question is, how can i extended the timer? Suppose while counting down in the 20th Minute, the user wishes to extend 15mins of the timer, i take the input as 15 from the user and after that, the timer should add this 15 mins to the existing time and fire the GUI app after 35mins. i.e, it should count from 35mins.In total after the time elapses, it would have been 50mins. How can I achieve this?

Actually setting the timer to 1 second is just fine. there will be no performance hit. just keep track of the DateTime when it started, then you can use the tick event to display the elapsed time and check if that duration is greater than what the user wants
private DateTime timerStart;
private TimeSpan duration;
private void Form1_Load(object sender, EventArgs e)
{
Timer MyTimer = new Timer();
MyTimer.Interval = 1000; // tick at one second to update the UI
MyTimer.Tick += new EventHandler(MyTimer_Tick);
duration = whatever...// Input from user
timerStart = DateTime.Now;
MyTimer.Start();
}
private void changeTimer(TimeSpan newValue) {
duration = newValue;
}
private void MyTimer_Tick(object sender, EventArgs e)
{
TimeSpan alreadyElapsed = DateTime.Now.Subtract(timerStart);
// update the UI here using the alreadyElapsed TimeSpan
if(alreadyElapsed > duration)
{
//pop my GUI application
}
}

That's easy to implement if you set your timer to a one second/minute interval and another variable to the number of seconds/minutes.
Decrease the variable value on each timer tick. Add to that variable if you need to expand the interval. If the variable value is 0,launch the other application.

not able to fire event (timer)

I have a function in winform that is executed every x time (eg. every 60 minutes).
And then it does some stuff, then I want it to wait some seconds (using a timer) and then execute do some stuff part2.
private void goToFtp(int time)
{
double interval = time* 60 * 1000;
System.Timers.Timer checkForTime = new System.Timers.Timer(interval);
checkForTime.Elapsed += new ElapsedEventHandler(checkForTime_Elapsed);
checkForTime.Enabled = true;
}
System.Windows.Forms.Timer timerDelayWatcher = new System.Windows.Forms.Timer();
private void checkForTime_Elapsed(object sender, ElapsedEventArgs e)
{
.......Do some stuff part1
timerDelayWatcher.Tick += new EventHandler(timerDelayWatcher_Tick); // Everytime timer ticks, timer_Tick will be called
timerDelayWatcher.Interval = (1000) * (5);
timerDelayWatcher.Enabled = true;
timerDelayWatcher.Start();
}
private void timerDelayWatcher_Tick(object sender, EventArgs e)
{
timerDelayWatcher.Stop();
.......Do some stuff part2
}
The problem is that the timerDelayWatcher_Tick is not fired...any ideias why?

You need use:
Thread.Sleep(5000);
But first you need add
using System.Threading;
or use
System.Threading.Thread.Sleep(5000);
on 5000 are the time in milliseconds
Sample
private void timerDelayWatcher_Tick(object sender, EventArgs e)
{
timerDelayWatcher.Stop();
System.Threading.Thread.Sleep(5000);
.......Do some stuff part2
}

Try calling the start method on the system.timers.timer firstly, and I would recommend sticking to one type of timer, and pattern of use, say use the system.timer.timer and do the work you need on elapsed, then restart with and wait for the next elapsed event.
Either that or I would suggest looking at the task library and async flow in .net 4/4.5 and as #Ferri suggests using a Sleep

Take also care on loosing reference to the class containing the timerDelayWatcher member.
If it happens the timer is disposed so no more events...

how to update timer on windows form while application is executing

I want to show timer on UI such that when aplication star executing timer starts with 00:00:00 and when it completed its execution timer stops. Timer should show timing per second while running.

You can use the System.Windows.Forms.Timer, which is created for scenarios like yours. You can read more about in MSDN.
You should use the following code snippet as sample:
Timer timer = new Timer();
timer.Interval = 1000;
timer.Tick += new System.EventHandler(timer_Tick);
timer.Start();
private void timer_Tick(object sender, System.EventArgs e)
{
this.Text = string.Format("{0:hh:MM:ss}", DateTime.Now);
}
Notice that you should dispose the Timer when you do not needed.

Repeating a code execution

I am trying to repeat a code execution after predefined time passes and i don't want to mess up things by using threads. Is the below code a good practice?
Stopwatch sw = new Stopwatch(); // sw constructor
EXIT:
// Here I have my code
sw.Start();
while (sw.ElapsedMilliseconds < 100000)
{
// do nothing, just wait
}
System.Media.SystemSounds.Beep.Play(); // for test
sw.Stop();
goto EXIT;

Use a timer instead of labels and StopWatch. You are doing busy waiting, tying up the CPU in that tight loop.
You start a timer, giving it an interval to fire on (100000 milliseconds), then run your code in the event handler for the Tick event.
See Comparing the Timer Classes in the .NET Framework Class Library in MSDN magazine.

You could use a timer what Oded suggested:
public partial class TestTimerClass : Form
{
Timer timer1 = new Timer(); // Make the timer available for this class.
public TestTimerClass()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
timer1.Tick += timer1_Tick; // Assign the tick event
timer1.Interval = 1000; // Set the interval of the timer in ms (1000 ms = 1 sec)
timer1.Start(); // Start the timer
}
void timer1_Tick(object sender, EventArgs e)
{
System.Media.SystemSounds.Beep.Play();
timer1.Stop(); // Stop the timer (remove this if you want to loop the timer)
}
}
EDIT: Just want to show you how to make an easy timer if you don't know how to :)