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)
    Label1: TLabel;
    Label2: TLabel;
    Edit1: TEdit;
    Edit2: TEdit;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation
var
  x:Real;        //声明一个全局变量，下面的所有函数与过程都能引用
{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
  x:=StrToFloat(Edit1.Text);
  Edit2.Text:=FloatToStr(Sin(x));
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  x:=StrToFloat(Edit1.Text);
  Edit2.Text:=FloatToStr(Sin(x)/Cos(x)); //求正切函数
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  x:=StrToFloat(Edit1.Text);
  Edit2.Text:=FloatToStr(Sqr(x));  //求平方函数
end;

procedure TForm1.Button4Click(Sender: TObject);
begin
  x:=StrToFloat(Edit1.Text);
  Edit2.Text:=FloatToStr(Ln(x)/Ln(10));//利用换底公式求常用对数
end;

end.