C# constructor event

Question

i created a class and when i create an employee object via form , i want to give a message;

this is my class, event and delegate

public delegate void cto         


        

Answer 1

Solution

Here's a generic approach to your problem

public class EventFactory
{
    public U Create(V constructorArgs)
    {
        var instance = (U)Activator.CreateInstance(typeof(U), constructorArgs);
        OnCreated?.Invoke();
        return instance;
    }

    public delegate void CreatedEventHandler();
    public event CreatedEventHandler OnCreated;
}

You can then do

var ef = new EventFactory();
ef.OnCreated += myEventHandler; 
var instance = ef.Create(employeeArgs);

.. Going further

It is possible to adjust my code to provide greater flexiblity when you need to pass event arguments or when the constructor is parameterless. I haven't tested it but it should look somewhere along the lines of

public class EventFactory
{
    public U Create(V constructorArgs, T eventArgs)
    {
        var instance = (U)Activator.CreateInstance(typeof(U), constructorArgs);
        OnCreated?.Invoke(eventArgs);
        return instance;
    }

    public U Create(T eventArgs)
    {
        return Create(null, eventArgs);
    }

    public delegate void CreatedEventHandler(T args);
    public event CreatedEventHandler OnCreated;
}

public class EventFactory
{
    public U Create(V constructorArgs)
    {
        var instance = (U)Activator.CreateInstance(typeof(U), constructorArgs);
        OnCreated?.Invoke();
        return instance;
    }

    public U Create() where U : new()
    {
        var instance = new U();
        OnCreated?.Invoke();
        return instance;
    }

    public delegate void CreatedEventHandler();
    public event CreatedEventHandler OnCreated;
}