unit1.pas

学习Delphi最好的教材。通过一个个简单而实用的实例

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Label1: TLabel;
    Button1: TButton;
    Button2: TButton;
    Panel1: TPanel;
    SpeedButton1: TSpeedButton;
    SpeedButton2: TSpeedButton;
    SpeedButton3: TSpeedButton;
    SpeedButton4: TSpeedButton;
    SpeedButton5: TSpeedButton;
    SpeedButton6: TSpeedButton;
    SpeedButton7: TSpeedButton;
    SpeedButton8: TSpeedButton;
    SpeedButton9: TSpeedButton;
    SpeedButton10: TSpeedButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure SpeedButton1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
  Label1.Caption:=Edit1.Text;
  //用户先在Edit1中写第一个数，按这个按钮把它保存到Label1中，
  Edit1.Text:='';
  //将Edit1清空、以便在Edit1中写第二个数。
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  add1,add2,sum:Integer;
  //变量add1表示第一个加数
  //变量add2表示第二个加数
  //变量sum表示计算它们的和
begin
  add1:=StrToInt(Label1.Caption);
  //从Label中取第一个加数，用函数StrToInt把它从String(字符串)
  //类型转化为Integer(整数)类型，存到变量add1中
  add2:=StrToInt(Edit1.Text);
  //从Edit1中取第二个加数，用函数StrToInt把它从String(字符串)
  //类型转化为Integer(整数)类型，存到变量add2中
  sum:=add1+add2;  //计算它们的和，存到变量sum中
  Edit1.Text:=IntToStr(sum);
  //把sum中的计算结果(先用函数IntToStr从Integer(整数)类型转化为
  //String(字符串)类型)写到Edit1中，显示出来。
end;

procedure TForm1.SpeedButton1Click(Sender: TObject);
begin
  Edit1.Text:=Edit1.Text+'1';
end;

end.