有人可以用最常规的方式向我解释如何使用EventArgs吗？

public class MyCustomEventArgs : EventArgs
{
    public string MyData { get; set; }
}

public class MyCustomEventSource
{
    public event EventHandler<MyCustomEventArgs> MyEvent;

    protected virtual void OnMyEvent(MyCustomEventArgs e)
    {
        MyEvent?.Invoke(this, e);
    }

    public void RaiseMyEvent()
    {
        OnMyEvent(new MyCustomEventArgs { MyData = "Hello, world!" });
    }
}

public class MyCustomEventHandler
{
    public void HandleMyEvent(object sender, MyCustomEventArgs e)
    {
        Console.WriteLine($"MyData: {e.MyData}");
    }
}

public static void Main(string[] args)
{
    MyCustomEventSource eventSource = new MyCustomEventSource();
    MyCustomEventHandler eventHandler = new MyCustomEventHandler();

    eventSource.MyEvent += eventHandler.HandleMyEvent;

    eventSource.RaiseMyEvent();
}