Bridge Design Pattern

Decouple an abstraction from its implementation so that the two can vary independently. The Bridge pattern is used for decoupling an abstraction from its implementation so that the two can vary independently. Bridge is a high-level architectural patterns and its main goal is through abstraction to help .NET developers write better code. A Bridge pattern is created by moving a set of abstract operations to an interface so that both the client and the service can vary independently.

using System;
using System.Collections.Generic;

namespace Patterns
{

class MainApp
{
/// <summary>
/// Entry point into console application.
/// </summary>
static void Main()
{
// Create RefinedAbstraction
Customers customers = new Customers { Group = "Chicago" };

// Set ConcreteImplementor
customers.DataObject = new CustomersData();

// Exercise the bridge
customers.Show();
customers.Next();
customers.Show();
customers.Next();
customers.Show();

customers.Add("Henry Velasquez");
customers.ShowAll();

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

/// <summary>
/// The 'Abstraction' class
/// </summary>
class CustomersBase
{
// Gets or sets customer group
public string Group { get; set; }

// Gets or sets data object
public IDataObject DataObject { get; set; }

public virtual void Next()
{
DataObject.NextRecord();
}

public virtual void Prior()
{
DataObject.PriorRecord();
}

public virtual void Add(string name)
{
DataObject.AddRecord(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();
}
}

/// <summary>
/// The 'RefinedAbstraction' class
/// </summary>
class Customers : CustomersBase
{
public override void ShowAll()
{
// Add separator lines
Console.WriteLine();
Console.WriteLine("------------------------");
base.ShowAll();
Console.WriteLine("------------------------");
}
}

/// <summary>
/// The 'Implementor' interface
/// </summary>
interface IDataObject
{
void NextRecord();
void PriorRecord();
void AddRecord(string name);
void DeleteRecord(string name);
void ShowRecord();
void ShowAllRecords();
}

/// <summary>
/// The 'ConcreteImplementor' class
/// </summary>
class CustomersData : IDataObject
{
private List<string> _customers;
private int _current = 0;

// Constructor
public CustomersData()
{
// Simulate loading from database
_customers = new List<string>
{ "Jim Jones", "Samual Jackson", "Allan Good",
"Ann Stills", "Lisa Giolani" };
}

public void NextRecord()
{
if (_current <= _customers.Count - 1)
{
_current++;
}
}

public void PriorRecord()
{
if (_current > 0)
{
_current--;
}
}

public void AddRecord(string customer)
{
_customers.Add(customer);
}

public void DeleteRecord(string customer)
{
_customers.Remove(customer);
}

public void ShowRecord()
{
Console.WriteLine(_customers[_current]);
}

public void ShowAllRecords()
{
_customers.ForEach(customer =>
Console.WriteLine(" " + customer));
}
}
}