Delphi初浅入门笔记之六:高级数据类型

在第一篇的Delphi初浅入门笔记之一 :Object-Pascal基础中,我列出了一些高级数据类型。但是在实际的学习中,我只接触了枚举类型。还有字节类型,数组类型等等需要掌握,如果需要用到Delphi做开发的话。

还是用源代码来说事吧:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{

在这里定义了一个名为week的枚举类型,可以看到定义枚举使用type关键字来定义的

}
type
  week=(sun,mon,tue,wed,thu,fri,sat);
{$R *.dfm}

{

这个函数返回string类型,它的作用是将枚举类型的值转换为友好的字符串形式。

}
function mday(day:week):string;
begin
    case day of
    sun:mday:='星期天';
    mon:mday:='星期一';
    tue:mday:='星期二';
    wed:mday:='星期三';
    thu:mday:='星期四';
    fri:mday:='星期五';
    sat:mday:='星期六';

    end;
end;
procedure TForm1.FormCreate(Sender: TObject);
var
year,month,day:word;
begin
    decodedate(date,year,month,day);
    edit1.Text:=format('%d年%d月%d日',[year,month,day]);
end;

procedure TForm1.Button1Click(Sender: TObject);
var
today,yesterday,tomorrow:week;
n:Integer;
begin
  n:=dayofweek(now);
  case n of
  1:today:=sun;
  2:today:=mon;
  3:today:=tue;
  4:today:=wed;
  5:today:=thu;
  6:today:=fri;
  7:today:=sat;
  end;

  if today=low(week) then
       yesterday:=high(week)
  else
      yesterday:=pred(today);
  if today=high(week) then
    tomorrow:=low(week)
  else
    tomorrow:=succ(today);
  button1.Caption:='昨天';
  button2.Caption:='今天';
  button3.Caption:='明天';
  case (sender as tButton).Tag of
  0:button1.Caption:='昨天是'+  mday(yesterday);
  1:button2.Caption:='今天是'+  mday(today);
  2:button3.Caption:='明天是'+  mday(tomorrow);
  end;
end;

end.

 

源代码

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