如何中断事件处理程序

Question

I don't know how can I break event handler method list.
For example I have follow code. What should i write in IF statement?

public event EventHandler myEvent;
...
myEvent += new EventHandler(met1);
myEvent += new EventHandler(met2);
myEvent += new EventHandler(met3);
...
public void met2(object sender, EventArgs e)
{
...
     if(myCondition)
     {
     //there I want to break execution of all methods assiciated with myEvent event
     //I want to break met2 and don't allow to execute met3
     }
...
}

Answer 1

You can define your delegate , so your custom event handler , whith its custom EventArgs , with boolean value.

Example:

public class MyEventArg : EventArgs {

    public bool Handle {get;set;}

}

myEvent += new MyEventHandler(met1);

public void met2(object sender, MyEventArgs e)
{

   if(e.Handled)
      return;

   if(myCondition)
   {
       e.Handled = true;
       return;
   }
...
}

In this way, if we in any other event handlder before processing it, check if Handled == true , one time it's set into that state from one of them, others would skip that event processing.

Just an idea example, you have to change it to fit your code exact needs.

Answer 2

Look into KeyDownEventArgs, there is an Property Handled wich can be set to true.
You could do something similar:

class myClass {
    public event EventHandler myEvent;

    myEvent += new EventHandler(met1);
    myEvent += new EventHandler(met2);
    myEvent += new EventHandler(met3);

    public void metN(object sender, MyCustomEventArgs e)
    {
        if(e.Cancel)
            return;

        // Do whatever you like

        if(<someBooleanStatement>)
        {
            e.Cancel = true;
            return;
        }

        // Do whatever you like
    }
}