Bridge

// Bridge pattern -- Real World example

using System; using System.Collections; namespace DoFactory.GangOfFour.Bridge.RealWorld {    // MainApp test application       class MainApp   {      static void Main()     {        // Create RefinedAbstraction       Customers customers =          new Customers("Chicago");        // Set ConcreteImplementor       customers.Data = new CustomersData();        // Exercise the bridge       customers.Show();       customers.Next();       customers.Show();       customers.Next();       customers.Show();       customers.New("Henry Velasquez");       customers.ShowAll();        // Wait for user       Console.Read();     }   }    // "Abstraction"    class CustomersBase   {      private DataObject dataObject;      protected string group;      public CustomersBase( string group)     {        this.group = group;     }      // Property      public DataObject Data     {        set{ dataObject = value; }        get{ return dataObject; }     }      public virtual void Next()     {       dataObject.NextRecord();     }      public virtual void Prior()     {       dataObject.PriorRecord();     }      public virtual void New( string name)     {       dataObject.NewRecord(name);     }      public virtual void Delete( string name)     {       dataObject.DeleteRecord(name);     }      public virtual void Show()     {       dataObject.ShowRecord();     }      public virtual void ShowAll()     {       Console.WriteLine("Customer Group: " + group);       dataObject.ShowAllRecords();     }   }    // "RefinedAbstraction"    class Customers : CustomersBase   {      // Constructor      public Customers( string group) : base(group)     {       }      public override void ShowAll()     {        // Add separator lines       Console.WriteLine();       Console.WriteLine ("------------------------");        base.ShowAll();       Console.WriteLine ("------------------------");     }   }    // "Implementor"    abstract class DataObject   {      public abstract void NextRecord();      public abstract void PriorRecord();      public abstract void NewRecord( string name);      public abstract void DeleteRecord( string name);      public abstract void ShowRecord();      public abstract void ShowAllRecords();   }    // "ConcreteImplementor"    class CustomersData : DataObject   {      private ArrayList customers = new ArrayList();      private int current = 0;      public CustomersData()     {        // Loaded from a database       customers.Add("Jim Jones");       customers.Add("Samual Jackson");       customers.Add("Allen Good");       customers.Add("Ann Stills");       customers.Add("Lisa Giolani");     }      public override void NextRecord()     {        if (current <= customers.Count - 1)       {         current++;       }     }      public override void PriorRecord()     {        if (current > 0)       {         current--;       }     }      public override void NewRecord( string name)     {       customers.Add(name);     }      public override void DeleteRecord( string name)     {       customers.Remove(name);     }      public override void ShowRecord()     {       Console.WriteLine(customers[current]);     }      public override void ShowAllRecords()     {        foreach ( string name in customers)       {         Console.WriteLine(" " + name);       }     }   } }