Pre-beginner's guide to using a timer

• Download zipped source - 6.6 Kb

Introduction

This is my first C# article in a long time. A couple of days ago, Paul Watson was chatting with me on Sonork and he suddenly mentioned that in VB he used to use some function called Now() which used to give him the current date and time instantly. He was complaining that he couldn't find the corresponding .NET function. That's when I did a quick check and discovered the DateTime class or rather structure.

Of course this article is not about the DateTime structure. I suddenly wondered how to use timer based procedures from C#. We all use SetTimer once in a while when we code and it struck me as odd that I never wondered about this in C#. Luckily I had that new Petzold book and Chapter 10 was dedicated to timers and time related functions. Just one page on timers though, though to be fair to him, that was all that was needed. I then played around with it a little.

This article will simply show you how to use them, though if you have the Petzold book that's all you need really. I am also including as an example project, a program that will wait on you and keep popping up a reminder Yes/No message at the time interval you specify, till you click on Yes.

Using Timers

We use the System.Windows.Forms.Timer class for our timer purposes. First we need to create a Timer object. Then we need to set the timer interval. This is accomplished as follows :-

Timer timer01 = new Timer();
timer01.Interval = 1000;

The Timer class has a Tick event. That's exactly what we needed eh? We add our timerproc as our Timer object's event handler as follows :-

timer01.Tick += new EventHandler(timerproc);

Then we simply enable the timer.

timer01.Enabled = true;

That's it. Now every 1000 milliseconds [cause that's the amount we specified], the timerproc gets called.

The timer proc

Within our form class we'll need a function like this :-

void timerproc(object o1, EventArgs e1)
{
	//blah blah blah

	//blah blah blah

	//blah blah blah

}

Say, you want to close the timer after some time. Then you can do this :-

((Timer)o1).Stop();
((Timer)o1).Tick -= new EventHandler(timerproc);

Before I sign off I better tell you how to get the current time, since that's how this whole article got started :-)

DateTime.Now.ToLongTimeString();

Now people like Paul won't complain that .NET is tougher than VB ;-)

Conclusion

I am fully aware of the enormously high flame potential this article has and that it is a pre-beginner level thing that I have explained here. But I was quite delighted when I got the timer working and I thought there might be other idiots like me who would be similarly happy. And I simply could not resist the temptation to write another CP article, specially since I have temporarily ceased work on my planned Winsock series.