Observer pattern (Observer behavioral) C # Simple Example

Observer pattern (Observer behavioral) C # Simple Example

A few key points: the pattern makes the dependency between the target and the observation both loosely coupled and the notification automatically propagated

Example: A series of changes occurred after the player hit the enemy: After the explosion, the enemy less than 1 ....

namespace adapterpattern{public partial class Observerform:form {public Observerform () {        InitializeComponent ();            } private void Btndisplay_click (object sender, EventArgs e) {basedata.enemynumber = 100;            IObserver explosionevent = new Explosionevent ();            IObserver enemy = new Enemy ();            Player P1 = new Player1 (); P1.            Addobserver (explosionevent); P1.            Addobserver (enemy); P1.            Notify (); ListBox1.Items.Add (P1.        Display ());        }} public static class basedata//data broker {public static string displaystring {get; set;}    public static int Enemynumber {get; set;}        Public abstract class Player {list<iobserver> observers = new list<iobserver> ();//Observer list public virtual void Notify () {foreach (IObserver Observer in observers) {OB Server.        Update ();//A Notice to the Observer    }} public virtual void Addobserver (IObserver observer)//Add observer {observers.        ADD (Observer); } public virtual void Delet (IObserver observer)//delete observer {observers.        REMOVE (Observer);    } public abstract string Display (); } public class Player1:player {public override string Display () {return basedata.displa        Ystring + BaseData.EnemyNumber.ToString ();    }} public interface iobserver//Observer interface {void Update (); } public class Explosionevent:iobserver//Observer 1 {public void Update () {basedata.displays        Tring = "show explosion"; }} public class Enemy:iobserver//Observer 2 {public void Update () {Basedata.enemynumber       -= 1;         "The number of enemies decreased by 1"; }    }}

Observer pattern (Observer behavioral) C # Simple Example