unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Edit2: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    Button1: TButton;
    ComboBox1: TComboBox;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
year,month,day:integer;
begin
 year:=strtoint(edit1.Text);
 month:=strtoint(combobox1.Text);
 case month of
  1,3,5,7,8,10,12:day:=31;
  4,6,9,11:day:=30;
  2:if(year mod 4=0)and(year mod 100<>0)or(year mod 400=0)
   then day:=29
   else day:=28;
end;
   edit2.Text:=inttostr(year)+'年'+inttostr(month)+'月是'+inttostr(day)+'天';

 end;
 end.