C# 设计模式系列教程-外观模式

 /// <summary>
 /// 子系统中的一个类
 /// </summary>
 public class SubSystemOne
 {
  public void MethodeOne()
  {
   Console.WriteLine("Sub System first method.");
  }
 }

 /// <summary>
 /// 子系统中一个类
 /// </summary>
 public class SubSystemTwo
 {
  public void MethodTwo()
  {
   Console.WriteLine("Sub System second method.");
  }
 }

 /// <summary>
 /// 子系统中一个类
 /// </summary>
 public class SubSystemThree
 {
  public void MethodThree()
  {
   Console.WriteLine("Sub System third method.");
  }
 }

 /// <summary>
 /// 子系统中一个类
 /// </summary>
 public class SubSystemFour
 {
  public void MethodFour()
  {
   Console.WriteLine("Sub System fourth method.");
  }
 }

 /// <summary>
 /// 外观类
 /// </summary>
 public class Facade
 {
  private SubSystemOne one;
  private SubSystemTwo two;
  private SubSystemThree three;
  private SubSystemFour four;

  public Facade()
  {
   one = new SubSystemOne();
   two = new SubSystemTwo();
   three = new SubSystemThree();
   four = new SubSystemFour();
  }

  public void MethodA()
  {
   Console.WriteLine("\nMethod group A----");
   one.MethodeOne();
   two.MethodTwo();
   four.MethodFour();
  }

  public void MethodB()
  {
   Console.WriteLine("\nMethod group B----");
   two.MethodTwo();
   three.MethodThree();
  }
 }

 class Program
 {
  static void Main(string[] args)
  {
   // 由于Facade的作用，客户端可以根本不知道子系统类的存在
   Facade facade = new Facade();
   facade.MethodA();
   facade.MethodB();

   Console.Read();
  }
 }

 public class Employee
 {
  public string Name { get; set; }
  public int Age { get; set; }

  public Salary Salary { get; set; }
 }

 public class Salary
 {
  public DateTime From { get; set; }
  public DateTime To { get; set; }
  public decimal Amount { get; set; }
 }

 public class EmployeeDataAccess
 {
  public void SaveEmployee(Employee employee)
  {
   Console.WriteLine("Save employee to database.");
  }

  public void DeleteEmployee(Employee employee)
  {
   Console.WriteLine("Remode employee from database.");
  }
 }

 public class SalaryDataAccess
 {
  public void SaveSalary(Salary salary)
  {
   Console.WriteLine("Save salary to database.");
  }

  public void DeleteSalary(Salary salary)
  {
   Console.WriteLine("Remove salary from database.");
  }
 }

 /// <summary>
 /// DataAccess为客户端提供一个简单的接口
 /// </summary>
 public class DataAccess
 {
  private EmployeeDataAccess employeeDataAccess = new EmployeeDataAccess();
  private SalaryDataAccess salaryDataAccess = new SalaryDataAccess();

  public void SaveEmployee(Employee employee)
  {
   // 先保存员工基本信息
   employeeDataAccess.SaveEmployee(employee);

   // 保存员工薪水信息
   salaryDataAccess.SaveSalary(employee.Salary);
  }

  public void RemoveEmployee(Employee employee)
  {
   // 先删除员工薪水信息
   salaryDataAccess.DeleteSalary(employee.Salary);

   // 删除员工基本信息
   employeeDataAccess.DeleteEmployee(employee);
  }
 }

 class Program
 {
  static void Main(string[] args)
  {
   DataAccess.DataAccess dataAccess = new DataAccess.DataAccess();
   DataAccess.Employee employee = new DataAccess.Employee() { Salary = new DataAccess.Salary(), Name = "Wang Kevin", Age = 22 };

   dataAccess.SaveEmployee(employee);
   dataAccess.RemoveEmployee(employee);

   Console.Read();
  }
 }