How do i create timer loop so that every t seconds the same function is performed

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I have

C#

t.Enabled = true;
            while (t.Enabled == true)
            {
                scroll(telep.Handle, (speedslider.Value * 2));
            }

where t is my timer. scroll(telep.Handle, (speedslider.Value * 2)); is short for a very very long and boring function, that pretty much scrolls the scrollbar by the value of a track bar multiplied by two (2).
Using while (t.Enabled == true) is not very good because if I try to interact with the form while it is scrolling, the form becomes unresponsive for a sec, then is scrolled all the way to the bottom.

I was thinking of using a timer for scrolling 2 pixels every, lets say for e.g., 30 milliseconds, but I do not know much about timers.

If someone could throw me into the correct direction, or even completely tell me how to do this, that would be great.

thanks to all who answer.:thumbsup:

Posted 20-Feb-11 21:39pm

vlad781

Updated 20-Feb-11 22:52pm

Dalek Dave

v2

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Comments

Albin Abel 21-Feb-11 3:43am

why don't you delegate the scroll function to a separate thread? Handle the timer's tick event for executing at intervels

vlad781 21-Feb-11 4:46am

here is how the scroll works, i made an article about it:
http://www.codeproject.com/KB/cs/Automatic_Scroll_Effect.aspx

Dalek Dave 21-Feb-11 4:52am

Edited for Readability and Grammar.

vlad781 21-Feb-11 4:58am

um, thanks?

2 solutions

Solution 2

Hi You can use very well Dylan's solution. That should work

Alternatively (However not recommended for a UI thred)......
Use the Threading timer as shown in the example below...it won't make your form unresponsive, because the timer will be in a different thread.

C#

public partial class Form1 : Form
 {
     private static int Count = 0;
     public Form1()
     {
         InitializeComponent();
     }

     private void Form1_Load(object sender, EventArgs e)
     {
         System.Threading.Timer timer = new System.Threading.Timer(new System.Threading.TimerCallback(MyIntervalFunction));
         timer.Change(0, 2000);
     }
     private void MyIntervalFunction(object obj){
         Count++;
         if (label1.InvokeRequired == true)
         {
             this.Invoke((MethodInvoker)delegate
             {
                 label1.Text = Count.ToString();
             });
         }
         else
         {
             label1.Text = Count.ToString();
         }
     }
 }

The count will be added to the label, still your form will be responsive.This is an example and you can use the MyIntervalFunction for your requirement

Posted 20-Feb-11 22:44pm

Albin Abel

Updated 21-Feb-11 0:29am

v2

Comments

Dalek Dave 21-Feb-11 4:52am

Good answer.

vlad781 21-Feb-11 4:56am

hmmm, this seems legit. but i do not understand it, because well, i just dont know much about timers. do you think you can explain in further detail?

Albin Abel 21-Feb-11 5:49am

System.Threading.Timer timer = new System.Threading.Timer(new System.Threading.TimerCallback(MyIntervalFunction));
the above call instantiate the timer. It is not the same as timer control...where I am pass the a delegate reference of a function. This function will be executed in a different thread than the main UI thread. SO the UI thread become still responsive.

timer.Change(0, 2000); // this start the timer execute the MyIntervalFunction at 2 sec interval, because i given 2000 milliseconds as argument in the Change method call.

if (label1.InvokeRequired == true)
{
this.Invoke((MethodInvoker)delegate
{
label1.Text = Count.ToString();
});
}
else
{
label1.Text = Count.ToString();
}

This is the standard way of handling controls when working with multiple thread. The controls can't be updated cross thread. So you have to check is invoke required. If so use a method invoker to invoke the control operations.

Replace the label with your scroll function. If any control is accessed in the scroll then that has to be handled through method invoker

Is it clear?

here is the documentation for method invoker

http://msdn.microsoft.com/en-us/library/system.windows.forms.methodinvoker.aspx

here is the documentation of timer

http://msdn.microsoft.com/en-us/library/system.threading.timer.aspx

vlad781 21-Feb-11 11:32am

ok, thanks a lot. so i would replace the part with the label with my
scroll(telep.handle, (scrollspeed.Value * 2));
method?

vlad781 21-Feb-11 11:34am

ok, isee now.

vlad781 21-Feb-11 11:40am

i want to replace if (label1.InvokeRequired == true) with a button click. i tried if (scrolldown.click) but it says click can only appear on the left side of += or -=

vlad781 30-Jun-11 18:09pm

i want to replace if (label1.InvokeRequired == true) with a button click. i tried if (scrolldown.click) but it says click can only appear on the left side of += or -=

Albin Abel 21-Feb-11 5:50am

Thanks Dalek Dave

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Dylan Morley · Accepted Answer · 2011-02-20T21:47:00

Solution 1

Set the timers interval property, then create an event handler for the timers tick function.

Done!

C#

private Timer timer = new Timer();

public void Init()
{
    timer.Interval = 5000; // every 5 seconds
    timer.Tick += new EventHandler(timer_Tick);
    timer.Enabled = true;
}
void timer_Tick(object sender, EventArgs e)
{
    Console.WriteLine("This event will happen every 5 seconds");
}

Posted 20-Feb-11 21:47pm

Dylan Morley

Updated 20-Feb-11 22:37pm

v4

Comments

vlad781 21-Feb-11 4:30am

Im sorry, but this simply doesn't work. First, you didn't even create the timer correctly. try:
private Timer timer = new Timer();
you forgot^ but you did name it...
and even after fixing that, i get 6 errors as opposed to the initial 9. please try the code before posting it again.

Dylan Morley 21-Feb-11 4:38am

Was merely an example of how to control Interval + Tick (which are the important things here), not working production code!!

There you go though, fixed.

Dalek Dave 21-Feb-11 4:52am

Good Call.

vlad781 21-Feb-11 4:53am

i have so far:

private Timer t = new Timer();

public Form1()
{
InitializeComponent();

t.Interval = 30;
t.Tick += new EventHandler(t_Tick);
t.Enabled = true;
}
void t_Tick(object sender, EventArgs e)
{
Console.WriteLine("This event will happen every .3 seconds");
}
which is good... but now i need to know how to use it to be able to use my scroll function everytime there is a 'tick'