Events?

[FlyBoy]

ok,i got the idea of delegates,which are pointers to methods\functions...

but whay do i need events???? i mean i cant unerstand it that good...any idea how do understand it?????

 

looks on google...read msdn,and alot of more tutorials,but most of them arent that clear and understandable... :o :confused:

[rifter1818]

Hope this helps

 

ok,i got the idea of delegates,which are pointers to methods\functions...

but whay do i need events???? i mean i cant unerstand it that good...any idea how do understand it?????

 

looks on google...read msdn,and alot of more tutorials,but most of them arent that clear and understandable... :o :confused:

You dont "need" events, there are *always* (until someone gives me an example otherwise (not including the events allready there)) ways of coding to avoid needing events.. However they are very usefull especially when writing class's that other people will be using. Say you have a class and something important happens with varying frequency, maybe the program may have to react maybe it wont, with events you dont have to worry about whether its needed or not... Code example (because my writen descriptions suck).

/* Without Events */
//inside the dll
class MYCLASS
{
    int X;
    public virtual int x{
        get{return 1;}
        set{X = value;}
    }
}
////the dll users code
class fMYCLASS : MYCLASS
{
  override int x{
      get{
        someonewaslookingatx();
        return X;
       }
      set{
       someonechangedthevalueofx();
      X=value;
      }
    }
     void someonewaslookingatx(){...}
     void someonechangedthevalueofx(){...}
}
//With Events
//Dll Code
class MYCLASS
{
    int X;
    public delegate void PointlessEvent();
    public event PointlessEvent xget;
    public event PointlessEvent xset;
    public int x{get{if(xget!=null)xget();return X;}
       set{if(xset!=null)xset();return X;}
      }
}
//thier code no inherited class they can just classinstance.xget += new EventHandler(functionname)....

as you can see there is no need for a inheriting class with events, this style of solution can be used much better than shown but hopefully you get the idea.

[Joe Mamma]

'event' is a decoration to a delegate declaration.

 

Among other things, decorating a delegate field with event allows for multiple functions to be executed as a result of the event being fired.

 

 

Get Programming .NET Components (O'Reilly [4/2003], Lowy, ISBN:0596003471)

[rifter1818]

and there

 

Much better explination Joe Mamma

[FlyBoy]

AWESOM!!!! thank you very much!!!!!! ;)

 

eventually i dont think i gonna use events that much,i dont see (..yet) any use for them,that i cant do with delegates.

basically both of them (events and delegates) are method\indexers .... pointers..(am i right??) :confused: