Adapter Design Pattern

// Adapter pattern -- Structural example

using System;

namespace DoFactory.GangOfFour.Adapter.Structural
{

  // Mainapp test application

  class MainApp
  {
    static void Main()
    {
      // Create adapter and place a request
      Target target = new Adapter();
      target.Request();

      // Wait for user
      Console.Read();
    }
  }

  // "Target"

  class Target
  {
    public virtual void Request()
    {
      Console.WriteLine("Called Target Request()");
    }
  }

  // "Adapter"

  class Adapter : Target
  {
    private Adaptee adaptee = new Adaptee();

    public override void Request()
    {
      // Possibly do some other work
      // and then call SpecificRequest
      adaptee.SpecificRequest();
    }
  }

  // "Adaptee"

  class Adaptee
  {
    public void SpecificRequest()
    {
      Console.WriteLine("Called SpecificRequest()");
    }
  }
}

using System;

namespace DoFactory.GangOfFour.Adapter.RealWorld
{

  // MainApp test application

  class MainApp
  {
    static void Main()
    {
      // Non-adapted chemical compound
      Compound stuff = new Compound("Unknown");
      stuff.Display();
      
      // Adapted chemical compounds
      Compound water = new RichCompound("Water");
      water.Display();

      Compound benzene = new RichCompound("Benzene");
      benzene.Display();

      Compound alcohol = new RichCompound("Alcohol");
      alcohol.Display();

      // Wait for user
      Console.Read();
    }
  }

  // "Target"

  class Compound
  {
    protected string name;
    protected float boilingPoint;
    protected float meltingPoint;
    protected double molecularWeight;
    protected string molecularFormula;

    // Constructor
    public Compound(string name)
    {
      this.name = name;
    }

    public virtual void Display()
    {
      Console.WriteLine("\nCompound: {0} ------ ", name);
    }
  }

  // "Adapter"

  class RichCompound : Compound
  {
    private ChemicalDatabank bank;

    // Constructor
    public RichCompound(string name) : base(name)
    {
    }

    public override void Display()
    {
      // Adaptee
      bank = new ChemicalDatabank();
      boilingPoint = bank.GetCriticalPoint(name, "B");
      meltingPoint = bank.GetCriticalPoint(name, "M");
      molecularWeight = bank.GetMolecularWeight(name);
      molecularFormula = bank.GetMolecularStructure(name);

      base.Display();
      Console.WriteLine(" Formula: {0}", molecularFormula);
      Console.WriteLine(" Weight : {0}", molecularWeight);
      Console.WriteLine(" Melting Pt: {0}", meltingPoint);
      Console.WriteLine(" Boiling Pt: {0}", boilingPoint);
    }
  }

  // "Adaptee"

  class ChemicalDatabank
  {
    // The Databank 'legacy API'
    public float GetCriticalPoint(string compound, string point)
    {
      float temperature = 0.0F;

      // Melting Point
      if (point == "M")
      {
        switch (compound.ToLower())
        {
          case "water" : temperature = 0.0F; break;
          case "benzene" : temperature = 5.5F; break;
          case "alcohol" : temperature = -114.1F; break;
        }
      }
      // Boiling Point
      else
      {
        switch (compound.ToLower())
        {
          case "water" : temperature = 100.0F; break;
          case "benzene" : temperature = 80.1F; break;
          case "alcohol" : temperature = 78.3F; break;
        }
      }
      return temperature;
    }

    public string GetMolecularStructure(string compound)
    {
      string structure = "";

      switch (compound.ToLower())
      {
        case "water" : structure = "H20"; break;
        case "benzene" : structure = "C6H6"; break;
        case "alcohol" : structure = "C2H6O2"; break;
      }
      return structure;
    }

    public double GetMolecularWeight(string compound)
    {
      double weight = 0.0;
      switch (compound.ToLower())
      {
        case "water" : weight = 18.015; break;
        case "benzene" : weight = 78.1134; break;
        case "alcohol" : weight = 46.0688; break;
      }
      return weight;
    }
  }
}

// Adapter pattern -- .NET optimized

Two editions: C# and VB.NET

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