unit1.pas

本光盘是《Delphi 7应用教程》一书的配套光盘

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Edit2: TEdit;
    Edit3: TEdit;
    Edit4: TEdit;
    Button1: TButton;
    Button2: TButton;
    Label1: TLabel;
    Label2: TLabel;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
  num1,num2:Integer;    //定义2个局部整型变量
begin
  Edit3.Text:='';      //清空编辑框
  Edit4.Text:='';
  num1:=Random(100);   //将随机产生的小于100的非负整数赋值给num1
  num2:=Random(100);
  Edit1.Text:=IntToStr(num1);//将整型数据转换成字符串赋值给编辑框
  Edit2.Text:=IntToStr(num2);
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  n1,n2,n3:Integer;      //定义3个局部整型变量
begin
  n1:=StrToInt(Edit1.Text); //将字符串转换成整型数据赋值给变量
  n2:=StrToInt(Edit2.Text);
  n3:=StrToInt(Edit3.Text);
  if (n3=n1+n2) then     //双分支IF语句
    Edit4.Text:='答案正确'    //条件为真，执行本语句
  else
    Edit4.Text:='答案错误';   //条件为假，执行本语句
end;

end.