events are not heritable, are they?

[pschulz]

There is literature saying events are not heritable.
I made an code example, seems to me events a r e heritabel.

Maybe its something not really clear within oop world?
The example has 3 classes: cycel, bicycle, motorcycle and InvalidWhightEventArgs.

Cycel is the base, and there is declared the event InvalidWightEventHandler, occures if whight gets an invalid value.

The property whight is overwritten in the other classes, with intention. Cause the literature says futhermore, events rise only in those classes where they are declared.
So, the event in this example is only declared in cycle, but raises in all the others as well.

The code, Class Cycle:

public delegate void InvalidWightEventHandler(Cycle sender);

    public class Cycle
    {
        protected double mWight = 0;
      
        public event InvalidWightEventHandler InvalidWight;

        //Constructor
        public Cycle() { }

        //OnXx Methods
        protected virtual void OnInvalidWight(InvalidWhightEventArgs e)
        {
            if (InvalidWight != null)
                InvalidWight(this);
        }
        //Propertys
        public virtual double Wight
        {
            get
            {return mWight;}
            set
            {
                if (value >= 0)
                   {mWight = value;}
                else
                {
                    OnInvalidWight(new InvalidWhightEventArgs(value));
                }
            }
        }

        public override string ToString()
        {
            return "Cycle=" + "Cycle\n" + ", Wight=" + Wight;
        }
    }

Class BiCycle

 public class BiCycle : Cycle
    {
        //Constructor
        public BiCycle() { }

        //Propertys
        public override double Wight
        {
            get
            {
                return mWight;
            }
            set
            {
                //other conditions
                if (value >= 10)
                {
                    mWight = value;
                }
                else
                {
                    OnInvalidWight(new InvalidWhightEventArgs(value));
                }
            }
        }
        public override string ToString()
        {
            return "Cycle=" + "BiCyle\n" + ", Wight=" + Wight;
        }
    }

Class MotorCycle

public class MotorCycle: BiCycle
    {
        //Constructor
        public MotorCycle() { }      

        //Propertys
        public override  double Wight
        {
            get
            {return mWight;}
            set
            {
                //MotorCycle other conditions
                if (value >= 100)
                   {mWight = value; }
                else
                { 
                    OnInvalidWight(new InvalidWhightEventArgs(value));
                }
            }
        }
        public override string ToString()
        {
            return "Cycle=" + "MotorCyle\n" + ", Wight=" + Wight;
        }
    }

Class InvalidWhightEventArgs

 public class InvalidWhightEventArgs : EventArgs
    {
        // Fields
        private double mInvalidWhight;

        //Constructor
        public InvalidWhightEventArgs(double invalidWhight)
        {
            mInvalidWhight = invalidWhight;
        }

        //Propertys
        public double InvalidWhight
        {
            get { return mInvalidWhight; }
        }
    }

Class Programm

 class Program
    {
        static void Main(string[] args)
        {
            Cycle myC = new Cycle();
            BiCycle myB = new BiCycle();
            MotorCycle myM = new MotorCycle();

            myC.InvalidWight += myB_InvalidWight;
            myB.InvalidWight += myB_InvalidWight;
            myM.InvalidWight += myB_InvalidWight;

            myC.Wight = -1;
            myB.Wight = 1;
            myM.Wight = 10;

            Console.ReadLine();  
        }

        private static void myB_InvalidWight(object sender)
        {           
            Console.WriteLine("invalid wight: " + ((Object)sender).ToString());                     
        }
    }

[Arjay]

While the InvalidWhightEventArgs class is being used in classes that are inherited, the InvalidWhightEventArgs class itself is not inherited.

[pschulz]

Understand, but this is to me the event "public event InvalidWightEventHandler InvalidWight".
And I can call it here, as I call methods or protertys from a baseclass.

myB.InvalidWight...

[Arjay]

Give us a link to where you read that events are not inheritable (or quote the exact text of what you read). Also what .net version was the text referring to and what .net version are you using?

[pschulz]

Its from a german autor. I understand might be better to read it from the base, but, place his name here... I dont know, nowadays its like you put him on public turture. And its finally not available in english, never saw it.

[Arjay]

Its from a german autor. I understand might be better to read it from the base, but, place his name here... I dont know, nowadays its like you put him on public turture. And its finally not available in english, never saw it.

Ok. How about answering >> Also what .net version was the text referring to and what .net version are you using?

[pschulz]

well, have fogotten.
Used this example with VS2010 or VS2012, the text refers to VS2012

[pschulz]

I redused the code, so its without "InvalidWhightEventArgs "
which means, there is no way to use the event within BiCycle.
But the event its still usabel for Bicycle, same way as before.
myB.InvalidWight += myB_InvalidWight;
So long I dont need any diffrent in property wight, its fine.

From this perspective...yeah, might be possible to say, its not heritable

 public delegate void InvalidWightEventHandler();

    public class Cycle
    {
        protected double mWight = 0;

        public event InvalidWightEventHandler InvalidWight;

        //Constructor
        public Cycle() { }
        
        //Propertys
        public virtual double Wight
        {
            get
            { return mWight; }
            set
            {
                if (value >= 0)
                { mWight = value; }
                else
                {   // Ereignis auslösen
                    InvalidWight();
                }
            }
        }

        public override string ToString()
        {
            return "Cycle=" + "Cycle\n" + ", Wight=" + Wight;
        }
    }

static void Main(string[] args)
        {
            Cycle myC = new Cycle();
            BiCycle myB = new BiCycle();

            myC.InvalidWight += myB_InvalidWight;
            myB.InvalidWight += myB_InvalidWight;

            myB.Wight =- 1;
            myC.Wight = -1;          

            Console.ReadLine();
        }
        private static void myB_InvalidWight()
        {
            Console.WriteLine("invalid wight: ");
        }

[pschulz]

what .net version was the text referring to and what .net version are you using?

Hey Arjay, are you really really really sure it makes a different, carring this subject and using Vs2010 or 2012 or 2015 ??

If it sounds like I try to insult you, please let me know, i change it, I promise

[Arjay]

Folks probably aren't going to get much out of a thread where folks take 6 or 7 weeks to answer what they've already answered. Closing the thread.