Multicast delegate weird behavior in C#?

Question

I have this simple event :

public class ClassA
{
    public event Func Ev;
    public int Do(string l)
    {
        return Ev(l);
    }
}
         


        

Answer 1

The events are just iterated in the order they were attached. Because you are using a return value, the value you get is the last invoked.

This is not really a normal pattern for events though. You probably want something a bit more like:

public class MyEventArgs : EventArgs
{
    public MyEventArgs()
    {
        Results = new List();
    }
    public string InputString{get;set;}
    public List Results{get;set;}
}
public event EventHandler Ev
public int Do(string l)
{
    MyEventArgs e = new MyEventArgs();
    e.InputString = l;
    if(Ev != null) Ev(this, e);
    return e.Results.Sum();
}

and then

static int Display(object sender, MyEventArgs e)
        {
            return e.Results.Add(k.Length);
        }

  static int Display_2(object sender, MyEventArgs e)
        {
            return e.Results.Add(k.Length*10);
        }