We Keep Coding

linking timers to variables [closed]

Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 6 years ago.
Improve this question
I am making a food ordering desktop application , so i want to calculate time between ordering food and delivering food so i added timers to the app and made a start and end buttons , on starting i start a time and put it interval value ,make a variable counter, count and save its value on end button to database , what i want to made is to start a new timer dynamically on new orders and when ending an order stop its timer
i tried inserting 3 timers and made variables c1,c2,c3 and made a loop to start timers on every order if interval!=null , but i didn't know how to stop a specific timer on ending the order
code :
int c1=0;
int c2=0;
int c3=0;
private void button_start_Click(object sender, EventArgs e)
{
if (timer1.Interval == null)
{
timer1.Start();
timer1.Interval = 1000;
}
else if (timer2.Interval == null)
{
timer2.Start();
timer2.Interval = 1000;
}
else if (timer3.Interval == null)
{
timer3.Start();
timer3.Interval = 1000;
}
}

Well as you have not shown us any code, let me assume that you at least have a class to encapsulate order.
public class Order
{
public int OrderNumber{get;set;}
///other properties
}
Now if you add following two properties and a method, your problem is resolved.
public class Order
{
public int OrderNumber{get;set;}
//other properties
public DateTime OrderPlacedOn{get;set;}
public DateTime OrderCompletedOn{get;set;}
public TimeSpan TimeToComplete()
{
if(OrderCompletedOn==DateTime.MinValue)//order not completed yet
return TimeSpan.FromSeconds(0);
return OrderCompletedOn - OrderPlacedOn;
}
}
This saves you from keeping countless timers. You can set values of start and complete on clicking of your buttons.

In what time interval is the conditions in a while clause checked?

How do I wait for a specified time while showing the remaining time to wait?
I now solved it like this but I feel like this is a really bad way to do it:
//This is running in a BackgroundWorker:
Stopwatch watch = new Stopwatch();
watch.Start();
while(watch.ElapsedMilliseconds != SecondsToWait * 1000)
{
TimeToNextRefresh = ((SecondsToWait * 1000) - watch.ElapsedMilliseconds) / 1000;
Thread.Sleep(1);
}
watch.Stop();
So here I am guessing that the condition (watch.ElapsedMilliseconds != SecondsToWait * 1000) is checked every millisecond.
So the main question is; In what period is the condition of while checked and/or how do I improve the code I've written?

It depends on what's the code inside while loop!
For example, if you write some really long/time-consuming code in a while loop, each iteration of the while loop, or course, will be longer than a while loop that only has short/fast code.
Compare these two while loops:
while (true) {
Console.WriteLine("Hello");
}
and
while (true) {
Console.Beep(5000);
}
Each iteration of the first while loop is faster than that of the second one because Console.Beep(5000) takes 5 seconds and Console.WriteLine only takes a fraction of a second.
So you can't rely on while loops to count time.
This is what you should do:
Create an instance of System.Windows.Forms.Timer, not the System.Timers.Timer nor the System.Threading.Timer. I find the first one the most useful (others are more advanced).
Timer timer = new Timer();
timer.Interval = 1000; // 1000 means 1000ms aka 1 second
timer.Tick += TimerTicked;
timer.Start();
Now the compiler will tell you that TimerTicked is not defined, so let's go define that:
private void TimerTicked(object sender, EventArgs e) {
}
Now you're all set. The code in TimerTicked will be called every one second.
Let's say you want to measure a time of 10 seconds. After 10 seconds, you want to do something. So first create a variable called secondsLeft in the class level:
int secondsLeft = 10;
Now in TimerTicked, you want to check whether secondsLeft is 0. If it is, do that something, else, minus one:
if (secondsLeft == 0) {
DoSomething();
} else {
secondsLeft--;
}
And secondsLeft is the time remaining! You can display it on a label or something.
To pause the timer, simply
timer.Stop();

The exact interval in which your while condition is checked is hard to predict. Thread.Sleep(1); only tells the operating system that you want your thread to sleep for at least 1 millisecond. There is no guarantee that your thread will be active again after exactly 1ms. Actually you can rather be sure that it will be more than that. The thread is scheduled again after 1ms, but there will be a delay until he gets his CPU time slot.
The interval you want for your loop actually depends how you want to display the remaining time. If you want to display only seconds, why would you update that display every millisecond, although the text would change only every 1000ms?
A loop like that is probably not a good way to implement something like that. I would recommend a System.Threading.Timer:
// this Timer will call TimerTick every 1000ms
Timer timer = new Timer(TimerTick, null, 0, 1000);
and implement the handler
public void TimerTick(object sender)
{
// update your display
}
Note that you will have the "update your display" part on the UI thread again, as this method is called by the Timer on a different thread.

This code is can really make an infinite loop if a calculation just take longer than 1 miliseconds.
You can achieve your desired behaviour with a simple System.Winforms.Forms.Timer like this snipped below :
private int tickCount = 0;
private int remaining = 10;
private void timer1_Tick(object sender, EventArgs e)
{
remaining--;
textBox1.Text = remaining.ToString();
}
private void Form1_Load(object sender, EventArgs e)
{
timer1.Interval = 1000;
timer1.Enabled = true;
}
With this you can countdown from 10 seconds and every tick you write to a textbox the remaining seconds

How to make DispatcherTimer show time in a textbox and perform action when reaches a certain time in C#?

This is my second question on StackOverflow here. I posted my first question a while ago and got a working reply in no time, much impressed, much appreciated.
Anyways, so what I want to know is, how to get a DispatcherTimer to work and show time in a certain textbox and stop it when it reaches a certain time (let's say 60 seconds) and perform a function after 60 seconds.
What I'm basically using this for is :
Making a game, which has to stop after 60 seconds and show the scores or related stuff. So this requires me to show the time in a textbox and perform a function at 60 seconds or after that.
Here's more information :
Textbox is called "timerbox"
Here's the code I've tried :
DispatcherTimer dt = new DispatcherTimer();
private void TimerStart(object sender, RoutedEventArgs e)
{
dt.Interval = TimeSpan.FromSeconds(1);
dt.Tick += dt_Tick;
dt.Start();
}
int count = 0;
void dt_Tick(object sender, object e)
{
count = count + 1;
timerbox.Text = Convert.ToString(count);
}
It doesn't show the time in textbox, plus I don't know how to make it stop at certain point and perform a function.
Thank you for reaching here, please leave answers with full explanation as I'm a complete beginner :)
P.S. I'm using Windows Store App Development Environment in Visual Studio 2013.
And there's no "Timer" in it as there is in normal C# Environment.

AOA.
I am recently started learning c#. (interested in windows form application). Hope this help you.
if you just want to set timer for a curtain event.....
recommend you using timer ( in toolbox )......
follow steps, when you double click on timer1 VS will create a timer1_Tick function for you which will be called every timer you timer ticks.....
now what you want to do when timer1 icks write it in there....like this....
private void timer1_Tick(object sender, EventArgs e)
{
//enter your code here
}
now write timer1. and VS will display a list of avaliable function....
for example,
timer1.Interval = (60*1000); //enter time in milliseconds
now when you want to start the write......
timer1.Start();
and to stop timer at any timer call
timer1.Stop();
if you want to repeat timer just write timer1.start() in that tick function.....
plus, to set textbox text equal to timer1 time use something like
textBox1.Text = Convert.ToString(timer1.Interval);
Click here for more information on timer class
hope this help you,
in case of any confusion, just comment,.....

The normal flow of a DispatcherTimer would look like this:
First Set up your new Object, set up the a new EventHandler that will run your desired code each Tick and Set the Timespan for the desired Tick Interval.
public MainPage()
{
this.InitializeComponent();
timer = new DispatcherTimer();
timer.Tick += new EventHandler<object>(timer_Tick);
timer.Interval = TimeSpan.FromMilliseconds(bpm);
}
Set The Timer_Tick Envent
async Void timer_Tick(object Sender, object e)
{
await this.Dispatcher.RunAsync(Windows.UI.core.CoreDispatcherPriority.High, () =>
{
//Run the Code
textBox1.text = timer.interval.TotalMilliseconds.ToString();
});
You have to have a trigger to Start the Dispatcher(and to stop if you need to), for example a button
private void StartButton_Click()
{
timer.Start();
}
This example was done using The new windows 10 Universal App platform within VS2015, but I think it should look about the same in a normal windows 8 App

Using Timer and colour to display morse code

Hi Guys i'm trying to let my Screen blink a morse code out using timer , but no luck, can you spot any problem?
Sry but i feel sad for those who cant think out of the box and just mark a -2 without even understanding the situation.
Anyway, found about using await Task.Delay(100) but gridHalfFront.Opacity = 1; isnt being "activated" when its being read. not sure why.
async public void RunMorseCode()
{
foreach (char c in word.ToCharArray())
{
string rslt = Codes[c.ToString()].Trim();
foreach (char c2 in rslt.ToCharArray())
{
if (c2 == '.')
{
gridHalfFront.Opacity = 0;
await Task.Delay(100);
}
else
{
gridHalfFront.Opacity = 0;
await Task.Delay(1000);
}
gridHalfFront.Opacity = 1;
}
}
}

use System.Threading.Thread.Sleep(1000) and/or System.Threading.Thread.Sleep(3000) inside yr loop to make yr screen blink on and off
gridHalfFront.Opacity = 1;
if (c2 == '.')
{
System.Threading.Thread.Sleep(1000);
}
else
{
System.Threading.Thread.Sleep(3000);
}
gridHalfFront.Opacity = 0;
change it to the way it best for you, but dont use those timers

Your code is missing the Timer event handler. After calling Start() and after the elapsed time a Tick event from the Timer will be raised. There you have to change the opacity.

I think you are misunderstanding the use of a Timer. If you put the following code at the top of StartTimer you will see what I mean.
Console.WriteLine("Started {0}", inputTiming);
When you run you will get a bunch of timers are being created immediately. This is not what you want for two reasons. Firstly, they are all assigned to the same variable, so the second is 'logically' killing off the first, etc. Secondly, you don't want them created all at once, as all of the 1 second ones will all run at the same time after 1 second, and all of the 3 second ones will run together after 3 seconds. And, as already mentioned, to run code after the timer expires you need to hook up the event.
BIG EDITS Sorry didn't realise you were looking at Metro. What I have said above still holds, but I will back away from providing a solution.
Given the comments about Sleep() not working on Metro, I think you need to so all the code inside the timer for one character, and then set the interval for the next character from within the timer. Will provide some code in a few minutes...

Dynamic Search Result C#

i'm try to develope a list of result by a dynamic search in a text box.
Now i update the record when:
SearchBox.TextChanged += new EventHandler(SearchBox_TextChanged);`
But i have to wait every char that i write for the complete result of the list.
so if i search for example "com" the result is not words that contains "com" but only "c".
For have the result of "com" i need to write:
"c" -> Wait to complete search
"o" -> Wait to complete search
"m" -> Wait to complete search
How can i do for wait some time that the user write the word and then search?
Thanks.

You are not aware what user want to insert in text box, so may be is Cat, Contact, Com, Computer,... So you should restrict the search list by each keyword from user, also you can set a policy for example just search when the input length is at least 3.
Edit: The other way is to use Lazy pattern, means keep the last time of text changed, then in another thread (like timer) check if there is more than 2 second between last user change to current time, update your search: (timer interval is 2 second).
private DateTime lastChange = DateTime.Now;
private bool textChanged = false;
object lockObject = new object();
private void textChanged(object sender, EventArg e)
{
lock(lockObject)
{
lastChange = DateTime.Now;
textChanged = true;
}
}
private void timer1_Tick(object sender, EventArgs е)
{
lock(lockObject)
{
if (textChanged && lastChange > DateTime.Now.AddSeconds(-2)) // wait 2 second for changes
{
UpdateList(); // or the method for searching.
textChanged = false;
lastChange = DateTime.Now;
}
}
}

the easiest way is to add into the event handler a condition like a minimum length
private void SearchBox_TextChanged(Event e,...){
if(e.text.Length > 3)
search(e.text);
}

Use a Timer. On every TextChanged event,
start that timer if not running,
restart (stop & start) if already running,
On Timer's Tick event, write your code to update Search Results and stop timer.
This will give your users some time to write complete search key-words.
Usually Timer Interval can be around 1 Second.

You can create a Timer when your application starts, and then on every keystroke simply reset and re-start the timer.
When the user stops typing, the timer will execute and perform the search.

You can use timer with an Interval of some like 2 seconds and implement search within timer's Tick event. Enable timer within TextChanged event and once search completed then disable timer within Tick event.