unit1.pas

这是一本非常不错的书,觉得很实用,建议大家看下.

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    MainMenu1: TMainMenu;
    N1: TMenuItem;
    N2: TMenuItem;
    N3: TMenuItem;
    N4: TMenuItem;
    Edit1: TEdit;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    Button5: TButton;
    Button6: TButton;
    Button7: TButton;
    Button8: TButton;
    Button9: TButton;
    Button10: TButton;
    Button11: TButton;
    Button13: TButton;
    Button14: TButton;
    Button15: TButton;
    Button16: TButton;
    Button17: TButton;
    Button12: TButton;
    Button18: TButton;
    Button19: TButton;
    Button21: TButton;
    procedure N3Click(Sender: TObject);
    procedure Button8Click(Sender: TObject);
    procedure Button9Click(Sender: TObject);
    procedure Button10Click(Sender: TObject);
    procedure Button7Click(Sender: TObject);
    procedure Button6Click(Sender: TObject);
    procedure Button5Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button14Click(Sender: TObject);
    procedure Button12Click(Sender: TObject);
    procedure Button15Click(Sender: TObject);
    procedure Button11Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button17Click(Sender: TObject);
    procedure Button16Click(Sender: TObject);
    procedure Button13Click(Sender: TObject);
    procedure Button18Click(Sender: TObject);
    procedure Button19Click(Sender: TObject);
    procedure Button21Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
   n:integer;
   x:string;
   y,r,s:real;
   m:integer=0;

implementation

{$R *.dfm}

procedure TForm1.N3Click(Sender: TObject);
begin
close;
end;

procedure TForm1.Button8Click(Sender: TObject);
begin
If (Edit1.text='0')
Then
Edit1.Text:='7'
else
Edit1.Text:=Edit1.text+'7'
end;

procedure TForm1.Button9Click(Sender: TObject);
begin
If (Edit1.text='0')
Then
Edit1.Text:='8'
else
Edit1.Text:=Edit1.text+'8';
end;

procedure TForm1.Button10Click(Sender: TObject);
begin
If (Edit1.text='0')
Then
Edit1.Text:='9'
else
Edit1.Text:=Edit1.text+'9';
end;

procedure TForm1.Button7Click(Sender: TObject);
begin
If (Edit1.text='0')
Then
Edit1.Text:='4'
else
Edit1.Text:=Edit1.text+'4';
end;

procedure TForm1.Button6Click(Sender: TObject);
begin
If (Edit1.text='0')
Then
Edit1.Text:='5'
else
Edit1.Text:=Edit1.text+'5';
end;

procedure TForm1.Button5Click(Sender: TObject);
begin
If (Edit1.text='0')
Then
Edit1.Text:='6'
else
Edit1.Text:=Edit1.text+'6';
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
If (Edit1.text='0')
Then
Edit1.Text:='1'
else
Edit1.Text:=Edit1.text+'1';
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
If (Edit1.text='0')
Then
Edit1.Text:='2'
else
Edit1.Text:=Edit1.text+'2';
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
If (Edit1.text='0')
Then
Edit1.Text:='3'
else
Edit1.Text:=Edit1.text+'3';
end;

procedure TForm1.Button14Click(Sender: TObject);
begin
If (Edit1.text='0')
Then
Edit1.Text:='0'
else
Edit1.Text:=Edit1.text+'0';
end;

procedure TForm1.Button12Click(Sender: TObject);
begin
Edit1.Text:='-'
end;

procedure TForm1.Button15Click(Sender: TObject);
begin
Edit1.Text:=''
end;

procedure TForm1.Button11Click(Sender: TObject);
begin
n:=1;
m:=m+1;
if(m>1)
then
begin
y:=strtofloat(x)+strtofloat(edit1.Text);
x:=floattostr(y);
end
else
x:=Edit1.Text;
Edit1.Clear;
end;

procedure TForm1.Button4Click(Sender: TObject);
begin
n:=2;
m:=m+1;
if(m>1)
then
begin
y:=strtofloat(x)-strtofloat(edit1.Text);
x:=floattostr(y);
end
else
x:=Edit1.Text;
Edit1.Clear;
end;

procedure TForm1.Button17Click(Sender: TObject);
begin
n:=3;
m:=m+1;
if(m>1)
then
begin
y:=strtofloat(x)*strtofloat(edit1.Text);
x:=floattostr(y);
end
else
x:=Edit1.Text;
Edit1.Clear;
end;

procedure TForm1.Button16Click(Sender: TObject);
begin
n:=4;
m:=m+1;
if(m>1)
then
begin
y:=strtofloat(x)/strtofloat(edit1.Text);
x:=floattostr(y);
end
else
x:=Edit1.Text;
Edit1.Clear;
end;

procedure TForm1.Button13Click(Sender: TObject);
begin
case n of
1:y:=strtofloat(x)+strtofloat(Edit1.Text);
2:y:=strtofloat(x)-strtofloat(Edit1.Text);
3:y:=strtofloat(x)*strtofloat(Edit1.Text);
4:If(Edit1.Text='0')
then
Showmessage('你的输入有误')
else
y:=strtofloat(x)/strtofloat(Edit1.Text);
end;
Edit1.Text:=floattostr(y);
m:=0;
end;

procedure TForm1.Button18Click(Sender: TObject);
begin
r:=strtofloat(edit1.text);
if(edit1.text>'0')
then
edit1.text:=floattostr(sqrt(r))
else
showmessage('eorror');
end;

procedure TForm1.Button19Click(Sender: TObject);
begin
s:=strtofloat(edit1.text);
if(edit1.Text<>'0')
then
edit1.text:=floattostr(1/s)
else
edit1.text:='E';
end;

procedure TForm1.Button21Click(Sender: TObject);
begin
close;
end;

end.