daskstar.~pa

编译原理-文法等价转换

unit Daskstar;

interface

uses SysUtils,WinTypes, WinProcs, Classes, Graphics, Forms, Controls, Buttons,
  StdCtrls, ExtCtrls;

type
  Taskstart = class(TForm)
    OKBtn: TBitBtn;
    CancelBtn: TBitBtn;
    HelpBtn: TBitBtn;
    Bevel1: TBevel;
    Label1: TLabel;
    edit1: TEdit;
    procedure OKBtnClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  askstart: Taskstart;

implementation
    uses unit1;
{$R *.DFM}

procedure Taskstart.OKBtnClick(Sender: TObject);
var i:integer;
    j:integer;
begin
  edit1.setFocus;
  try
    i:=strtoint(edit1.text);
  except
    application.messagebox('请输入数字','错误!',mb_ok+MB_ICONSTOP);
    exit;
  end;
  j:=1;
  while (j<=form1.fzjnum) and (form1.fzjfuhao[j].index<>i) do
    j:=j+1;
  if j>form1.fzjnum
    then
      begin
        application.messagebox('请输入已有的非终结符号号码!','错误!',mb_ok+MB_ICONSTOP);
      end
    else
      begin
        ModalResult := mrOK;
      end;
end;

end.