aa.pas

delphi的学习资料

unit AA;

interface

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

type
  TfmAA = class(TForm)
    btnInc: TBitBtn;
    Lb1: TLabel;
    edt1: TEdit;
    btnDec: TBitBtn;
    procedure FormActivate(Sender: TObject);
    procedure edt1Exit(Sender: TObject);
    procedure btnIncClick(Sender: TObject);
    procedure btnDecClick(Sender: TObject);
  private    { Private declarations }
  public     { Public declarations }
  end;

var
  fmAA: TfmAA;
  n,step: Integer;

implementation

{$R *.DFM}

procedure Disp();
begin
  fmAA.Lb1.Caption:=IntToStr(n);
  if n<0 then
    fmAA.Lb1.Font.Color:=clRed
  else
    fmAA.Lb1.Font.Color:=clBlack;
end;

procedure TfmAA.FormActivate(Sender: TObject);
begin
  n:=10;  Step:=1;
end;

procedure TfmAA.edt1Exit(Sender: TObject);
begin
  step:=StrToInt(edt1.Text);
end;

procedure TfmAA.btnIncClick(Sender: TObject);
begin
  n:=n+step;
  Disp();
end;

procedure TfmAA.btnDecClick(Sender: TObject);
begin
  n:=n-step;
  Disp();
end;

end.