关于类的入门例子(2): 数字盒子

//类单元
unit NumBox;

interface

type
  TNumBox = class
  private
    FCount: Integer;
  public
    procedure AddOne;
    procedure AddFive;
    procedure ZeroCount;
    function GetCount: Integer;
  end;

implementation

{ TNumBox }

procedure TNumBox.AddOne;
begin
  Inc(FCount);
end;

procedure TNumBox.AddFive;
begin
  Inc(FCount,5);
end;

procedure TNumBox.ZeroCount;
begin
  FCount := 0;
end;

function TNumBox.GetCount: Integer;
begin
  Result := FCount;
end;

end.

//调用
unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses NumBox;

var NumBox1: TNumBox;

procedure TForm1.FormCreate(Sender: TObject);
begin
  NumBox1 := TNumBox.Create;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  NumBox1.AddOne;
  Text := IntToStr(NumBox1.GetCount);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  NumBox1.AddFive;
  Text := IntToStr(NumBox1.GetCount);
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  NumBox1.ZeroCount;
  Text := IntToStr(NumBox1.GetCount);
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  NumBox1.Free;
end;

end.