How Do I Change A Labels Text Property To Show The Elapsed Time Between 2 Events?

Question

0.00/5 (No votes)

See more:

I need to start a timer when a button is clicked, end it when a different button is clicked, and show the amount of time passed between the 2 events. My code is below and the timer is declared in a private class. It starts in 1 event, ends in another, and is converted to int32. This is then added to an int to give me an integer of the elapsed time. The integer is then converted to a string and placed in the label. Unfortunately it only does the interval (1 second).

C#

private System.Timers.Timer Timer = new System.Timers.Timer(1000);
private void btnNewProblem_Click(object sender, EventArgs e)
{
     Timer.Start();
}
private void btnCheckAnswer_Click(object sender, EventArgs e)
{
    Timer.Stop();
    time += Convert.ToInt32(Timer.Interval) / 1000;
    lblTimer.Text = time.ToString() + " Second(s)";
 }

A few things to note:
1. I know timer.interval is wrong. I tried this after seeing it on several forums.
2. This is for a class. The instructor wants it to show in only seconds, and be in interval notation.
3. The instructor also wants it to be a timer and not a stop watch.
Thanks in advance!

Posted 29-Mar-15 14:32pm

Member 11561872

Add a Solution

Comments

Sascha Lefèvre 29-Mar-15 20:48pm

As it's for a class I will only give you a hint so that you will have the opportunity to learn something :-D
Take a good look at this page, you should get a clue:
https://msdn.microsoft.com/en-us/library/system.timers.timer%28v=vs.110%29.aspx

Member 11561872 29-Mar-15 20:54pm

I checked that page already, but i don't see were it outputs it to a label? it outputs to the console with a separate event but i can't have that.

Sascha Lefèvre 29-Mar-15 20:58pm

Don't bother with setting the label text yet. Your first step is to determine the time between buttonclick1 and buttonclick2. "Remember" you could do anything in the event-handler-method instead of what's shown in that example...

Member 11561872 29-Mar-15 21:21pm

I still don't understand what I'm doing wrong. Based on everything we've been taught and all the research I've done my problem is occurring in the line:
time += Convert.ToInt32(Timer.Interval) / 1000;
But i don't know what to change. I would imagine I need to change Interval but anything i change it to breaks the code with the error "Input string was not in a correct format."

Sascha Lefèvre 29-Mar-15 21:30pm

Timer.Interval is the time interval in which the timer fires the "Elapsed"-event which in that microsoft-sample calls the OnTimedEvent-method. It's always 1000 in your case, so even if that line wouldn't give that error, the result wouldn't be the interval between buttonclick1 and buttonclick2 but instead be always 1000/1000 = 1.

How could it be helpful to have the event-handler-method (from the microsoft-sample) be called every 1 second?

Member 11561872 29-Mar-15 21:39pm

To be honest I don't know. But I don't think this is going in the right direction. We haven't even gone over event-handler-methods yet.

Member 11561872 29-Mar-15 21:58pm

ok, so i'm reading event handlers in my book. (I've already looked for timers. they don't even show up in the index). Im guessing it would be useful because the timer needs measured in seconds and it would be called each second independently of when the buttons clicked. So when either of the buttons are clicked would i be able to stop the timer at the current value and call that value specifically? If so then it would be as easy as subtracting the start value from the end value. Or am i thinking to much?

Sascha Lefèvre 29-Mar-15 22:04pm

The Timer doesn't offer you a start- and end-value - that's StopWatch-thinking ;-) You just tell it to call your eventhandler every 1 second and start it...

Member 11561872 29-Mar-15 22:04pm

Looking back at the link i can see what's happening better but i still don't see what's happening. What i see is this:
aTimer is the name of the timer
2000 is the interval in milliseconds. its really just 2 seconds.
the elapsed time property is equal to itself plus the OnTimedEvent method. Right?
But when looking at the event method it doesn't have a value to add. it just writes to the console. So where does it get a value?

Sascha Lefèvre 29-Mar-15 22:19pm

The "Elapsed-Property" is no property - it's an event. You can identify that by:
- in the doc it's listed under "Events"
- in the Intellisense-Popup it has a "lightning"-symbol
- according to naming-conventions it's a verb in past tense

The += syntax is special for events: It means that you add an eventhandler-method to the event so that it will be called when the event "fires" (you "subscribe" to the event). Similarly you can "unsubscribe" with -=

So this:
aTimer.Elapsed += OnTimedEvent;
will cause OnTimedEvent to be called each 2 seconds in the microsoft-sample.
The value to add to in that eventhandler-method is your job :-)

Member 11561872 29-Mar-15 22:30pm

Ok so how is that done?

Sascha Lefèvre 29-Mar-15 22:32pm

I think you're thinking too complicated ;-)

Member 11561872 29-Mar-15 22:33pm

Would that just be timer.start( ); ?

Sascha Lefèvre 29-Mar-15 22:37pm

timer.start(); starts your timer, meaning from that point on your eventhandler-method will be called each second. What do you want your program to do then, until the second button click?

Member 11561872 29-Mar-15 22:39pm

Nothing with the timer. It revolves around the user answering math problems. When the user submits their answer (The second button click) it puts the elapsed time into the label

Sascha Lefèvre 29-Mar-15 22:44pm

Ok. But the timer doesn't provide you the elapsed time since you started it - it just calls your eventhandler-method every second (hint hint). So how can you get the elapsed time then?

Member 11561872 29-Mar-15 22:47pm

Declare an integer set it = to itself + 1 each time the handler was called between the 2 button presses?

Sascha Lefèvre 29-Mar-15 22:48pm

Yep!

Sascha Lefèvre 29-Mar-15 23:24pm

And? :)

Member 11561872 29-Mar-15 23:37pm

Sorry, I was doing this at work and my shift ended. It's bedtime now but I'll compile it in the morning and let you know! Thanks!

Sascha Lefèvre 29-Mar-15 23:42pm

Alright - you're welcome!

Member 11561872 30-Mar-15 15:29pm

ok, so my instructor went over timers today. We created a timer named "timer1" with the toolbox.
i used int time as my counter. Under btnNewProblem i had:
timer1.enabled = true;
and under btnCheckAnswer i had:
timer1.enabled = false;
time = 0;
then by double clicking the timer on the form i created a tick event handler under which i had:
time++;
if (time > 1)
{
lblTimer.text = time.ToString() + "Seconds";
}
else
{
lblTimer.text = time.ToString() + "second";

and i actually understand what happening. The timers ticks trigger everything under it to happen. int time is originally set to 0, but is raised by 1 each time the timer ticks, which is set to an interval of 1000 milliseconds (1 second). So when btnNewProblem is clicked, the timer starts ticking, changing the label until btnCheckAnswer is clicked, stopping the timer and thus stopping the ticks. And by setting int time to 0 after stopping you reset your timer without changing it until the new problem button is pressed. ^.^

Sascha Lefèvre 30-Mar-15 15:45pm

Well done! :-)

Sascha Lefèvre 29-Mar-15 21:35pm

Disregard what I wrote about that error, brainfreeze. Don't know where that error is coming from when you change something but it doesn't matter anyway.

Sascha Lefèvre 29-Mar-15 21:39pm

One more thing: As you wrote yourself, you shouldn't use a StopWatch. A Timer is obviously no StopWatch - it serves a different purpose. But your current code looks like you're trying to use the Timer as if it were a StopWatch.

Member 11561872 29-Mar-15 21:42pm

I was actually. He hasn't really touched on timers too much and i can't find anything online that explains the difference between the 2

Sascha Lefèvre 29-Mar-15 21:47pm

Maybe he expects you to dig into the online documentation. Take a look at the very first sentence on the MSDN-Page on the Timer-class. That's what a timer does.

Sascha Lefèvre 29-Mar-15 21:48pm

It wouldn't make sense to ask you to use a timer but not to use an event-handler-method.

Sascha Lefèvre 29-Mar-15 21:57pm

And by the way - the two methods visible in your code excerpt are eventhandler-methods themselves. Just for button-click-events. An eventhandler-method for a timer-elapsed-event is basically exactly the same, just triggered by another event.

Member 11561872 29-Mar-15 21:59pm

Right but we haven't really gone over them. I got them by double clicking the button on the forms GUI. We haven't discussed the parts or how to create them.

Sascha Lefèvre 29-Mar-15 22:06pm

The doubleclicking in the forms designer is just a convenience. It doesn't do anything that you can't see in the microsoft-timer-sample.

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Abhinav S · Answer 1 · 2015-03-29T16:06:00

Solution 1

Use the StopWatch[^] class.

C#

Stopwatch stopwatch = new Stopwatch();

public Form1()
{
    InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
    stopwatch.Start();

}
private void button2_Click(object sender, EventArgs e)
{

    stopwatch.Stop();
    var milliSeocnds = stopwatch.ElapsedMilliseconds;
    MessageBox.Show(millSeconds + "milliseconds passed between the two clicks.");
}

Posted 29-Mar-15 16:06pm

Abhinav S

Comments

Member 11561872 29-Mar-15 22:09pm

I can't use a stopwatch for this assignment

Sascha Lefèvre 29-Mar-15 22:30pm

Abhinav, it would have been easy for me to provide him a solution over an hour ago. Instead I chose to direct him to find a solution because it's for his class. Apart from the fact that this is no solution for him it would have been respectful if you had refrained from posting at all.

Member 11561872 29-Mar-15 22:31pm

For which i do thank you. I don't quite understand yet but i am learning!