proxy pattern

proxy.cs

using System;

 

namespace DoFactory.GangOfFour.Proxy.RealWorld

{

  /// <summary>

  /// MainApp startup class for Real-World 

  /// Proxy Design Pattern.

  /// </summary>

  class MainApp

  {

    /// <summary>

    /// Entry point into console application.

    /// </summary>

    static void Main()

    {

      // Create math proxy

      MathProxy proxy = new MathProxy();

 

      // Do the math

      Console.WriteLine("4 + 2 = " + proxy.Add(4, 2));

      Console.WriteLine("4 - 2 = " + proxy.Sub(4, 2));

      Console.WriteLine("4 * 2 = " + proxy.Mul(4, 2));

      Console.WriteLine("4 / 2 = " + proxy.Div(4, 2));

 

      // Wait for user

      Console.ReadKey();

    }

  }

 

  /// <summary>

  /// The 'Subject interface

  /// </summary>

  public interface IMath

  {

    double Add(double x, double y);

    double Sub(double x, double y);

    double Mul(double x, double y);

    double Div(double x, double y);

  }

 

  /// <summary>

  /// The 'RealSubject' class

  /// </summary>

  class Math : IMath

  {

    public double Add(double x, double y) { return x + y; }

    public double Sub(double x, double y) { return x - y; }

    public double Mul(double x, double y) { return x * y; }

    public double Div(double x, double y) { return x / y; }

  }

 

  /// <summary>

  /// The 'Proxy Object' class

  /// </summary>

  class MathProxy : IMath

  {

    private Math _math = new Math();

 

    public double Add(double x, double y)

    {

      return _math.Add(x, y);

    }

    public double Sub(double x, double y)

    {

      return _math.Sub(x, y);

    }

    public double Mul(double x, double y)

    {

      return _math.Mul(x, y);

    }

    public double Div(double x, double y)

    {

      return _math.Div(x, y);

    }

  }

}