TQueue 和 TStack, 一个是队列列表, 一个是堆栈列表; 一个是先进先出, 一个是先进后出.

TStack 主要有三个方法、一个属性:
Push(压栈)、Pop(出栈)、Peek(查看下一个要出栈的元素);
Count(元素总数).


本例效果图:

泛型容器单元(Generics.Collections)[3]: TStack<T>   堆栈列表-LMLPHP


代码文件:


unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls; type
  TForm1 = class(TForm)
    Memo1: TMemo;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
  end; var
  Form1: TForm1; implementation {$R *.dfm} uses Generics.Collections; {Delphi 2009 新增的泛型容器单元} type
  TRec = record
    Name: string;
    Age: Word;
  end; var
  Stack: TStack<TRec>;  {定义一个泛型 TStack 类, 这指定了要用于上面定义的 TRec 记录} {建立}
procedure TForm1.FormCreate(Sender: TObject);
begin
  Stack := TStack<TRec>.Create;   Memo1.Clear;
  Button1.Caption := Button1.Caption + ' 压栈';
  Button2.Caption := Button2.Caption + ' 出栈';
  Button3.Caption := Button3.Caption + ' 下一个出栈的...';
end; {释放}
procedure TForm1.FormDestroy(Sender: TObject);
begin
  Stack.Free;
end; {压栈: Push}
procedure TForm1.Button1Click(Sender: TObject);
var
  rec: TRec;
begin
  rec.Name := StringOfChar(Char( + Random()), );
  rec.Age := Random();
  Stack.Push(rec);
  Text := Format('当前队列成员总数: %d', [Stack.Count]);   {让 Memo1 配合显示}
  Memo1.Lines.Add(Format('%s, %d', [rec.Name, rec.Age]));
end; {出栈: Pop}
procedure TForm1.Button2Click(Sender: TObject);
var
  rec: TRec;
begin
  if Stack.Count = then Exit;
  rec := Stack.Pop;
  ShowMessage(Format('%s, %d', [rec.Name, rec.Age]));
  Text := Format('当前队列成员总数: %d', [Stack.Count]);   {让 Memo1 配合显示}
  Memo1.Lines.Delete(Memo1.Lines.Count - );
end; {下一个出列的的元素: Peek}
procedure TForm1.Button3Click(Sender: TObject);
var
  rec: TRec;
begin
  if Stack.Count = then Exit;
  rec := Stack.Peek;
  ShowMessage(Format('%s, %d', [rec.Name, rec.Age]));
end; end.

窗体文件:


object Form1: TForm1
  Left =
  Top =
  Caption = 'Form1'
  ClientHeight =
  ClientWidth =
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  Position = poDesktopCenter
  OnCreate = FormCreate
  OnDestroy = FormDestroy
  PixelsPerInch =
  TextHeight =
  object Memo1: TMemo
    Left =
    Top =
    Width =
    Height =
    Align = alLeft
    Font.Charset = DEFAULT_CHARSET
    Font.Color = clWindowText
    Font.Height = -
    Font.Name = 'Courier New'
    Font.Style = []
    Lines.Strings = (
      'Memo1')
    ParentFont = False
    ScrollBars = ssBoth
    TabOrder =
  end
  object Button1: TButton
    Left =
    Top =
    Width =
    Height =
    Caption = 'Button1'
    TabOrder =
    OnClick = Button1Click
  end
  object Button2: TButton
    Left =
    Top =
    Width =
    Height =
    Caption = 'Button2'
    TabOrder =
    OnClick = Button2Click
  end
  object Button3: TButton
    Left =
    Top =
    Width =
    Height =
    Caption = 'Button3'
    TabOrder =
    OnClick = Button3Click
  end
end
05-06 11:12