学步园

type
  TMonth = 1..12;
  Tdate = 1..31;
  Ta = class
  private
    Fyear: Integer;
    Fmonth: TMonth;
    Fdate: Tdate;
  public
    procedure GetDate(var aYear: Integer; var Amonth: TMonth; var Adate: Tdate);
    constructor create(aYear: integer = 2012; Amonth: Tmonth = 12; Adate: Tdate = 21);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

constructor Ta.create(aYear: integer = 2012; Amonth: Tmonth = 12; Adate: Tdate = 21);
begin
  inherited create;
  FYear := aYear;
  Fmonth := Amonth;
  Fdate := Adate;
end;

procedure Ta.GetDate(var aYear: integer; var Amonth: Tmonth; var Adate: Tdate);
begin
  aYear := Fyear;
  Amonth := Fmonth;
  Adate := FDate;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  MyDate: Ta;
  mYear: integer;
  mMonth: TMonth;
  mDate: Tdate;
begin
  MyDate := Ta.create(2013,1,13);
  MyDate.GetDate(mYear, mMonth, mDate);
  ShowMessageFmt('%d年%d月%d日', [mYear, mMonth, mdate]);
  FreeAndNil(MyDate);
end;