WPF: Cách sử dụng Raise Event trong C#

Để có thể ném một sự kiện ta làm các bước sau:

Bước 1: Khai báo phương thức uỷ quyền

    // Events are handled with delegates, so we must establish a MyEventHandler as a delegate 

     public delegate void MyEventHandler(object sender, EventArgs e); 

Bước 2: Khai báo Event

    // Now, create a public event "MyEvent" whose type is our MyEventHandler delegate. 

    public event MyEventHandler MyEvent;

Bước 3: Ném sự kiện

    public void MyMethod() {

        EventArgs MyArgs = new EventArgs();  

        // Now, raise the event by invoking the delegate. Pass in  the object that initated the event (this) as well as EventArgs. 

        // The call must match the signature of MyEventHandler.

        MyEvent(this, MyArgs);

    } 

Ví dụ:

    public class MyTextBox : System.Windows.Controls.TextBox

    {

        // Events are handled with delegates, so we must establish a MyEventHandler as a delegate

        public delegate void MyEventHandler(object sender, EventArgs e);

 

        // Now, create a public event "MyEvent" whose type is our MyEventHandler delegate.

        public event MyEventHandler MyEvent;

        public void MyMethod()

        {

            EventArgs MyArgs = new EventArgs();

 

            // Now, raise the event by invoking the delegate. Pass in  the object that initated the event (this) as well as EventArgs.

            // The call must match the signature of MyEventHandler.

            MyEvent(this, MyArgs);

        }

    }