How to use event created in interface

Question

0.00/5 (No votes)

See more:

C#

public interface MyEvent{
    event EventHandler myNewEvent;
}

I don't know how to init this event in same class and call it in some other class. Any help pls. I like something like:

C#

public class MyClass : MonoBehaviour, MyEvent {
     public delegate void EventHandler();
     public event EventHandler myNewEvent; // But here I have error

}

How to do this?

Posted 11-Nov-14 11:10am

Zoran Panev

Updated 11-Nov-14 21:38pm

v2

Add a Solution

Comments

Sergey Alexandrovich Kryukov 11-Nov-14 17:25pm

"Handler", not "Hendler".
—SA

2 solutions

Add a Solution

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Sergey Alexandrovich Kryukov · Answer 1 · 2014-11-11T11:30:00

This is quite possible, with implicit interface implementation. Your problem is unrelated to the peculiarities of event members in the interfaces. Your only problem is the definition of EventHandler; you can simply use available System.EventHandler.

For example:

C#

public class MonoBehaviour { /* ... */ }

public interface MyEvent{
    event System.EventHandler myNewEvent;
}

public class MyClass : MonoBehaviour, MyEvent {
    // public delegate EventHendler; // remove it, it is already defined
    public event System.EventHandler myNewEvent; // no problem here
}

If and when you need your own delegate type (unlikely; usually it's enough to only define the class derived from System.EventArgs and use the event handler type instantiated from the generic type System.EventHander<your_event_args_type_here>), make sure the definition is accessible where you use it.

—SA

BillWoodruff · Answer 2 · 2014-11-11T23:15:00

I assume that if you wish to implement a custom event based on an Interface, you'll probably want to have a custom EventArgs class for passing custom data:

C#

public interface MyEvent
{
    // EventHandler<t> available since .NET 2.0
    event EventHandler<customeventargs> myNewEvent;
}

public class CustomEventArgs : EventArgs
{
    public int Number { set; get; }
    public string Name { set; get; }

    public CustomEventArgs(int number, string name)
    {
        Number = number;
        Name = Name;
    }
}

public class ImplementsMyEventInterface : MyEvent
{
    public event EventHandler<customeventargs> myNewEvent;
    
    protected virtual void OnMyNewEvent(CustomEventArgs args)
    {
        EventHandler<customeventargs> handler = myNewEvent;
        if (handler != null) handler(this, args);
    }
}

// example of use:

private void SomeForm_Load(object sender, EventArgs e)
{
    var instanceOfMyEvent = new ImplementsMyEventInterface ();
    
    instanceOfMyEvent.myNewEvent += instanceOfMyEvent_myNewEvent;
}

// EventHandler in Form
private void instanceOfMyEvent_myNewEvent(object sender, CustomEventArgs e)
{
    Console.WriteLine("In EventHandler for implementation of 'myNewEvent in instance of the class 'usesMyEvent");
    Console.WriteLine("e.Number = {0} e.Name = {1}", e.Number, e.Name);
}

// example of raising the event:

private void SomeButton_Click(object sender, EventArgs e)
{
    instanceOfMyEvent_myNewEvent(this, new CustomEventArgs(number: 100, name: "hello"));
}</customeventargs></customeventargs></customeventargs></t>

How to use event created in interface

2 solutions

Solution 1

Solution 2

Add your solution here

Preview 0

How to use event created in interface

2 solutions

Solution 1

Solution 2

Add your solution here

Preview 0

Existing Members

...or Join us