unit1.pas

这有很多Delphi应用的例子

unit Unit1;

interface

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

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

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
      Number : Integer;
begin
        Number := StrToInt(Edit1.Text);
        case Number of
          1,3,5,7,9: Label1.Caption := '奇数';
          0,2,4,6,8: Label1.Caption := '偶数';
          10..100:
                 begin
                   Label1.Caption := '在10到100之间';
                   Form1.Color := clBlue;
                 end;
        else
          Label1.Caption := '大于100或为负数';
        end;
end;

end.