Event system explained in detail

   

using System;

namespace Demo
{
    //step 0. use event to simply complex interaction, independent data process module

    //step 1. declare a event signatrue
    public delegate void OnUserDeviceInsertedEvent(object sender, UserDeviceInsertedArgs e);

    //step 2. declare the event args
    public class UserDeviceInsertedArgs : EventArgs
    {
        public string DeviceData;
    }

    //step 3. declare a real work class which has 1 event field member and 1 working method member, in the method event will be triggered when condiation ready

    public class MagCard
    {
        public OnUserDeviceInsertedEvent OnDeviceInserted;
        public void StartingWork()
        {
            UserDeviceInsertedArgs data = new UserDeviceInsertedArgs();
            data.DeviceData = "Demo Data";
            if (OnDeviceInserted != null)
            {
                OnDeviceInserted(this, data);
            }
        }
    }

    //step 4. in main system, ord the event and supperly suitable process
    static class Program
    {
        /// <summary>
        /// ??????????
        /// </summary>
        [STAThread]
        static void Main()
        {
            MagCard machine = new MagCard();
            machine.OnDeviceInserted += new OnUserDeviceInsertedEvent(EventHandler_OnDeviceInserted);
            machine.StartingWork();
            Console.ReadKey();
        }

        private static void EventHandler_OnDeviceInserted(object sender, UserDeviceInsertedArgs e)
        {
            Console.ForegroundColor = ConsoleColor.Magenta;
            Console.WriteLine(e.DeviceData);
            Console.ResetColor();
        }
    }
    //Coding by MoonKite,2010-June,Study C#
    //Thanks for Java2s,I learned a lot form this website.
}