用 C# 实现了示例并优化了一下:

Subject.cs

public class Subject

{

private readonly List _observers = new List();

private int _state;

public int State

{

get => _state;

set

{

_state = value;

NotifyAllObservers();

}

}

public void AddObserver(Observer observer)

{

observer.Subject = this;

_observers.Add(observer);

}

public void NotifyAllObservers() => _observers.ForEach(o => o.Update());

}

Observer.cs

public abstract class Observer

{

public Subject Subject;

public abstract void Update();

}

BinaryObserver.cs

public class BinaryObserver:Observer

{

public BinaryObserver()

{

}

public BinaryObserver(Subject subject)

{

subject.AddObserver(this);

}

public override void Update()

{

Console.WriteLine($"Binary String: {Convert.ToString(Subject.State, 2)}");

}

}

OctalObserver.cs

public class OctalObserver:Observer

{

public OctalObserver()

{

}

public OctalObserver(Subject subject)

{

subject.AddObserver(this);

}

public override void Update()

{

Console.WriteLine($"Octal String: {Convert.ToString(Subject.State, 8)}");

}

}

HexaObserver.cs

public class HexaObserver:Observer

{

public HexaObserver()

{

}

public HexaObserver(Subject subject)

{

subject.AddObserver(this);

}

public override void Update()

{

Console.WriteLine($"Hex String: {Convert.ToString(Subject.State, 16)}");

}

}

Demo.cs

public void NumberChange()

{

Subject subject1 = new Subject();

new BinaryObserver(subject1);

new OctalObserver(subject1);

new HexaObserver(subject1);

Console.WriteLine("1 state=15");

subject1.State = 15;

Console.WriteLine("1 state=10");

subject1.State = 10;

Subject subject2 = new Subject();

subject2.AddObserver(new BinaryObserver());

subject2.AddObserver(new OctalObserver());

subject2.AddObserver(new HexaObserver(subject1));

Console.WriteLine("2 state=15");

subject1.State = 15;

Console.WriteLine("2 state=10");

subject1.State = 10;

}

DHclly

DHclly

335***817@qq.com2年前 (2018-08-06)