How do i add EventHandlers to my Inherited or custom classes?

[dahwan]

[Homogenn]

I don't understand your question. "EventHandler" is just a delegate, usually used to manage events thrown by forms or controls.

[dahwan]

Well, F. inst.

I have inherited a form and added a timer. I want an Event on each tick, so when i create the form, it'd go like

CustomForm.Ctick += new EventHandler(CustomForm_Ctick);

Get it?

[Homogenn]

Put this in the form's code. Then you can subscribe to the event you call "Ctick" with an EventHandler delegate.

public event EventHandler Ctick;

To fire the event, write something like (depends obviously on what you want to be sender and what EventArgs you want).

Ctick(this, new EventArgs());

[battula32]

Hi,
If you want to creare totally new custom event handler,
First create a public event class like this

public class clsCustomEvenArgs : EventArgs
{
        public string m_sEvent1;
        public string m_sEvent2;
        public clsEventTableArgs(string sEvent1, string sEvent2)
        {
            m_sEvent1= sEvent1;
            m_sEvent2= sEvent2;
        }
 }
//This is public event handler. sEvent1,sEvent2 are events which you want to send *** argumets.

inside your other code where you want to rise these events., define one parametirised delegate "clsCustomEvenArgs " as an argument. Also define one event like this.

public delegate void EventTable(object sender, clsCustomEvenArgs e);
public event EventTable evtYourEvent;//For Custom events

Inside your Timer code

private void timer1_Tick(object sender, EventArgs e)
{
      if(/*your condition)
      {
              clsCustomEvenArgs args = new clsCustomEvenArgs ((string)arg1, (string)arg2);//Pass your arguments
                evtYourEvent(this, args);//For custom event data
      }
}

This will do


Regards
Ravi.Battula

[boudino]

Just small correction: the event fire must be done this way:

if (evtYourEvent != null) evtYourEvent(this, args)

because the evtYourEvent has not to be set, so you could get NullReferenceException.

If you would like to be absolutely sure and correct, you should use:

EventTable tmpEvent = evtYourEvent;
if (tmpEvent != null) tmpEvent(this, args)

because someone can accidentaly remove the last handler from the event between the null check and the invocation.