C #6.0 (C # vNext): Event initializers

C #6.0 (C # vNext): Event initializers
Event initializers)

The new feature in C #6.0 allows you to initialize the event processing function directly when creating an instance, as shown below:

Example 1:

new Customer { Notify += MyHandler };

Example 2:

var client = new WebClient{    DownloadFileCompleted += DownloadFileCompletedHandler};

Example 3:

var button = new Button { ... Click += (source, e) => ... ... };

In another example, initialize an event directly.

public virtual event EventArgs RoslynReleased = delegate { };

Next we will compare the original and new writing methods:

public class Person{    private int _age;    public int Age    {        get        {            return _age;        }        set        {            _age = value;            OnAgeChanged(EventArgs.Empty);        }    }    public string Name { get; set; }    public event EventHandler AgeChanged;    protected virtual void OnAgeChanged(EventArgs e)    {        if (AgeChanged != null)        {            AgeChanged(this, e);        }    }    public override string ToString()    {        return string.Format("Name:{0}, Age:{1}", Name, Age);    }}

Previous writing:

var person = new Person { Age = 30, Name = "Calvin" };person.AgeChanged += (s, e) => Console.WriteLine("Person:{0}", ((Person)s));person.Age += 1;

New statement:

var person2 = new Person { Age = 30, Name = "Kelly", AgeChanged += (s, e) => Console.WriteLine("Person:{0}", ((Person)s)); };person2.Age += 1;