C# – How to subscribe to other class’ events in C#

.net-2.0cevent handlingevents

A simple scenario: a custom class that raises an event. I wish to consume this event inside a form and react to it.

How do I do that?

Note that the form and custom class are separate classes.

Best Answer

public class EventThrower
{
    public delegate void EventHandler(object sender, EventArgs args) ;
    public event EventHandler ThrowEvent = delegate{};

    public void SomethingHappened() => ThrowEvent(this, new EventArgs());
}

public class EventSubscriber
{
    private EventThrower _Thrower;

    public EventSubscriber()
    {
        _Thrower = new EventThrower();
        // using lambda expression..could use method like other answers on here

        _Thrower.ThrowEvent += (sender, args) => { DoSomething(); };
    }

    private void DoSomething()
    {
       // Handle event.....
    }
}

Related Solutions

C# – Calling the base constructor in C#

Modify your constructor to the following so that it calls the base class constructor properly:

public class MyExceptionClass : Exception
{
    public MyExceptionClass(string message, string extrainfo) : base(message)
    {
        //other stuff here
    }
}

Note that a constructor is not something that you can call anytime within a method. That's the reason you're getting errors in your call in the constructor body.

C# – How to cast int to enum

From an int:

YourEnum foo = (YourEnum)yourInt;

From a string:

YourEnum foo = (YourEnum) Enum.Parse(typeof(YourEnum), yourString);

// The foo.ToString().Contains(",") check is necessary for enumerations marked with an [Flags] attribute
if (!Enum.IsDefined(typeof(YourEnum), foo) && !foo.ToString().Contains(","))
{
    throw new InvalidOperationException($"{yourString} is not an underlying value of the YourEnum enumeration.")
}

Update:

From number you can also

YourEnum foo = (YourEnum)Enum.ToObject(typeof(YourEnum) , yourInt);

Best Answer

Related Solutions

C# – Calling the base constructor in C#

C# – How to cast int to enum

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