Delphi 设计模式：《HeadFirst设计模式》Delphi7代码

      容器的主要职责有两个：存放元素和浏览元素。根据单一职责原则（SRP）要将二者分开，于是将浏览功能打包封装就有了迭代器。
      用迭代器封装对动态数组的遍历：
1.容器中的元素类
{《HeadFirst设计模式》之迭代器模式 }
{ 容器中的元素类 }
{ 编译工具：Delphi7.0 }
{ E-Mail ：xshlife@163.com }

unit uItem;

interface

type
TMenuItem = class(TObject)
private
FName: String;
FDescription: String;
FVegetarian : Boolean;
FPrice: Double;
public
constructor Create(aName, aDescription: String;
aVegetarian : Boolean;
aPrice: Double);
function GetName: String;
function GetDescription: String;
function GetPrice: Double;
function IsVegetarian: Boolean;
end;

implementation

{ TMenuItem }

constructor TMenuItem.Create(aName, aDescription: String;
aVegetarian: Boolean;
aPrice: Double);
begin
FName := aName;
FDescription := aDescription;
FVegetarian := aVegetarian;
FPrice := aPrice;
end;

function TMenuItem.GetDescription: String;
begin
Result := FDescription;
end;

function TMenuItem.GetName: String;
begin
Result := FName;
end;

function TMenuItem.GetPrice: Double;
begin
Result := FPrice;
end;

function TMenuItem.IsVegetarian: Boolean;
begin
Result := FVegetarian;
end;

end.

2.迭代器
{《HeadFirst设计模式》之迭代器模式 }
{ 迭代器：封装对容器的遍历 }
{ 编译工具：Delphi7.0 }
{ E-Mail ：xshlife@163.com }

unit uIterator;

interface

uses
uItem;

type
TMenuItems = array of TMenuItem;

TIterator = class(TObject)
public
function HasNext: Boolean; virtual; abstract;
function Next : TObject; virtual; abstract;
end;

TDinerMenuIter