Стан на C#

using System; namespace RefactoringGuru.DesignPatterns.State.Conceptual { // The Context defines the interface of interest to clients. It also // maintains a reference to an instance of a State subclass, which // represents the current state of the Context. class Context { // A reference to the current state of the Context. private State _state = null; public Context(State state) { this.TransitionTo(state); } // The Context allows changing the State object at runtime. public void TransitionTo(State state) { Console.WriteLine($"Context: Transition to {state.GetType().Name}."); this._state = state; this._state.SetContext(this); } // The Context delegates part of its behavior to the current State // object. public void Request1() { this._state.Handle1(); } public void Request2() { this._state.Handle2(); } } // The base State class declares methods that all Concrete State should // implement and also provides a backreference to the Context object, // associated with the State. This backreference can be used by States to // transition the Context to another State. abstract class State { protected Context _context; public void SetContext(Context context) { this._context = context; } public abstract void Handle1(); public abstract void Handle2(); } // Concrete States implement various behaviors, associated with a state of // the Context. class ConcreteStateA : State { public override void Handle1() { Console.WriteLine("ConcreteStateA handles request1."); Console.WriteLine("ConcreteStateA wants to change the state of the context."); this._context.TransitionTo(new ConcreteStateB()); } public override void Handle2() { Console.WriteLine("ConcreteStateA handles request2."); } } class ConcreteStateB : State { public override void Handle1() { Console.Write("ConcreteStateB handles request1."); } public override void Handle2() { Console.WriteLine("ConcreteStateB handles request2."); Console.WriteLine("ConcreteStateB wants to change the state of the context."); this._context.TransitionTo(new ConcreteStateA()); } } class Program { static void Main(string[] args) { // The client code. var context = new Context(new ConcreteStateA()); context.Request1(); context.Request2(); } } } 

Context: Transition to ConcreteStateA. ConcreteStateA handles request1. ConcreteStateA wants to change the state of the context. Context: Transition to ConcreteStateB. ConcreteStateB handles request2. ConcreteStateB wants to change the state of the context. Context: Transition to ConcreteStateA.