Calculator (with a decimal point )...

Unit jisuanqiu;

Interface

Uses
Windows, messages, sysutils, variants, classes, graphics, controls, forms,
Dialogs, stdctrls, extctrls;

Type
Tform1 = Class (tform)
Button1: tbutton;
Button2: tbutton;
Button3: tbutton;
Button4: tbutton;
Button5: tbutton;
Button6: tbutton;
Button7: tbutton;
Button8: tbutton;
Button9: tbutton;
Button10: tbutton;
Button11: tbutton;
Button12: tbutton;
Button13: tbutton;
Button14: tbutton;
Button15: tbutton;
Panel1: tpanel;
Edit1: tedit;
Button17: tbutton;
Button16: tbutton;
Button18: tbutton;
Procedure button1click (Sender: tobject );
Procedure button2click (Sender: tobject );
Procedure button3click (Sender: tobject );
Procedure button4click (Sender: tobject );
Procedure button5click (Sender: tobject );
Procedure button6click (Sender: tobject );
Procedure button7click (Sender: tobject );
Procedure button8click (Sender: tobject );
Procedure button9click (Sender: tobject );
Procedure button10click (Sender: tobject );
Procedure button12click (Sender: tobject );
Procedure button13click (Sender: tobject );
Procedure button14click (Sender: tobject );
Procedure button15click (Sender: tobject );
Procedure button17click (Sender: tobject );
Procedure button16click (Sender: tobject );
Procedure button11click (Sender: tobject );
Procedure formshow (Sender: tobject );
Procedure button18click (Sender: tobject );
Private
{Private Declarations}
Public
{Public declarations}
End;

VaR
Form1: tform1;
// Num, num1, num2: integer;
S, J, I, s_number, s_type, s_characterlast: string;
Implementation

{$ R *. DFM}

Procedure tform1.button1click (Sender: tobject );
Begin
If s_type = '1' then begin
Edit1.text: = edit1.text + '1 ';
S: = '000000'; End
Else begin
Edit1.text: = '';
Edit1.text: = edit1.text + '1 ';
S_type: = '1 ';
End;
End;
Procedure tform1.button2click (Sender: tobject );
Begin
If s_type = '1' then begin
Edit1.text: = edit1.text + '2 ';
S: = '000000'; End
Else begin
Edit1.text: = '';
Edit1.text: = edit1.text + '2 ';
S_type: = '1 ';
End;
End;

Procedure tform1.button3click (Sender: tobject );
Begin
If s_type = '1' then begin
Edit1.text: = edit1.text + '3 ';
S: = '000000'; End
Else begin
Edit1.text: = '';
Edit1.text: = edit1.text + '3 ';
S_type: = '1 ';
End ;;
End;

Procedure tform1.button4click (Sender: tobject );
Begin
If s_type = '1' then begin
Edit1.text: = edit1.text + '4 ';
S: = '000000'; End
Else begin
Edit1.text: = '';
Edit1.text: = edit1.text + '4 ';
S_type: = '1 ';
End;
End;

Procedure tform1.button5click (Sender: tobject );
Begin
If s_type = '1' then begin
Edit1.text: = edit1.text + '5 ';
S: = '000000'; End
Else begin
Edit1.text: = '';
Edit1.text: = edit1.text + '5 ';
S_type: = '1 ';
End;
End;

Procedure tform1.button6click (Sender: tobject );
Begin
If s_type = '1' then begin
Edit1.text: = edit1.text + '6 ';
S: = '000000'; End
Else begin
Edit1.text: = '';
Edit1.text: = edit1.text + '6 ';
S_type: = '1 ';
End;
End;

Procedure tform1.button7click (Sender: tobject );
Begin
If s_type = '1' then begin
Edit1.text: = edit1.text + '7 ';
S: = '000000'; End
Else begin
Edit1.text: = '';
Edit1.text: = edit1.text + '7 ';
S_type: = '1 ';
End;
End;

Procedure tform1.button8click (Sender: tobject );
Begin
If s_type = '1' then begin
Edit1.text: = edit1.text + '8 ';
S: = '000000'; End
Else begin
Edit1.text: = '';
Edit1.text: = edit1.text + '8 ';
S_type: = '1 ';
End;
End;

Procedure tform1.button9click (Sender: tobject );
Begin
If s_type = '1' then begin
Edit1.text: = edit1.text + '9 ';
S: = '000000'; End
Else begin
Edit1.text: = '';
Edit1.text: = edit1.text + '9 ';
S_type: = '1 ';
End;
End;

Procedure tform1.button10click (Sender: tobject );
Begin

If s_type = '1' then begin
Edit1.text: = edit1.text + '0 ';
S: = '000000'; End
Else begin
Edit1.text: = '';
Edit1.text: = edit1.text + '0 ';
S_type: = '1 ';
End;

End;

Procedure tform1.button12click (Sender: tobject );
Begin
S_type: = '0 ';
If S = ''then
Application. MessageBox ('Enter the number first, 'prompt:', 0)
Else
If I <> ''then
Begin
If s_characterlast = 'X' then
Begin
Edit1.text: = floattostr (strtofloat (s_number) * strtofloat (edit1.text ));
S_number: = edit1.text;
S_characterlast: = '+ ';
I: = '';
End;

If s_characterlast = '+' then
Begin
Edit1.text: = floattostr (strtofloat (s_number) + strtofloat (edit1.text ));
S_number: = edit1.text;
S_characterlast: = '+ ';
I: = '';
End;

If s_characterlast = '-' then
Begin
Edit1.text: = floattostr (strtofloat (s_number)-strtofloat (edit1.text ));
S_number: = edit1.text;
S_characterlast: = '+ ';
I: = '';
End;

If s_characterlast = '/' then
Begin
Edit1.text: = floattostr (strtofloat (s_number)/strtofloat (edit1.text ));
S_number: = edit1.text;
S_characterlast: = '+ ';
I: = '';
End;
End
//**************//
Else
Begin
S_characterlast: = '+ ';
S_number: = edit1.text;
I: = '000000 ';
End;
J: = '000000 ';
End;

Procedure tform1.button13click (Sender: tobject );
Begin
S_type: = '0 ';
If S = ''then

Application. MessageBox ('Enter the number first, 'prompt:', 0)
Else
If I <> ''then
Begin
If s_characterlast = 'X' then
Begin
Edit1.text: = floattostr (strtofloat (s_number) * strtofloat (edit1.text ));
S_number: = edit1.text;
S_characterlast: = '-';
I: = '';
End;

If s_characterlast = '+' then
Begin
Edit1.text: = floattostr (strtofloat (s_number) + strtofloat (edit1.text ));
S_number: = edit1.text;
S_characterlast: = '-';
I: = '';
End;

If s_characterlast = '-' then
Begin
Edit1.text: = floattostr (strtofloat (s_number)-strtofloat (edit1.text ));
S_number: = edit1.text;
S_characterlast: = '-';
I: = '';
End;

If s_characterlast = '/' then
Begin
Edit1.text: = floattostr (strtofloat (s_number)/strtofloat (edit1.text ));
S_number: = edit1.text;
S_characterlast: = '-';
I: = '';
End;
End
//**************//
Else
Begin
S_characterlast: = '-';
S_number: = edit1.text;
I: = '000000 ';
End;
J: = '000000 ';
End;

Procedure tform1.button14click (Sender: tobject );
Begin
S_type: = '0 ';
If S = ''then

Application. MessageBox ('Enter the number first, 'prompt:', 0)
Else
If I <> ''then
Begin
If s_characterlast = 'X' then
Begin
Edit1.text: = floattostr (strtofloat (s_number) * strtofloat (edit1.text ));
S_number: = edit1.text;
S_characterlast: = 'X ';
I: = '';
End;

If s_characterlast = '+' then
Begin
Edit1.text: = floattostr (strtofloat (s_number) + strtofloat (edit1.text ));
S_number: = edit1.text;
S_characterlast: = 'X ';
I: = '';
End;

If s_characterlast = '-' then
Begin
Edit1.text: = floattostr (strtofloat (s_number)-strtofloat (edit1.text ));
S_number: = edit1.text;
S_characterlast: = 'X ';
I: = '';
End;

If s_characterlast = '/' then
Begin
Edit1.text: = floattostr (strtofloat (s_number)/strtofloat (edit1.text ));
S_number: = edit1.text;
S_characterlast: = 'X ';
I: = '';
End;
End
//**************//
Else
Begin
S_characterlast: = 'X ';
S_number: = edit1.text;
I: = '000000 ';
End;
J: = '000000 ';
End;

Procedure tform1.button15click (Sender: tobject );
Begin
S_type: = '0 ';
If S = ''then
Application. MessageBox ('Enter the number first, 'prompt:', 0)
Else
If I <> ''then
Begin
If s_characterlast = 'X' then
Begin
Edit1.text: = floattostr (strtofloat (s_number) * strtofloat (edit1.text ));
S_number: = edit1.text;
S_characterlast: = '/';
I: = '';
End;

If s_characterlast = '+' then
Begin
Edit1.text: = floattostr (strtofloat (s_number) + strtofloat (edit1.text ));
S_number: = edit1.text;
S_characterlast: = '/';
I: = '';
End;

If s_characterlast = '-' then
Begin
Edit1.text: = floattostr (strtofloat (s_number)-strtofloat (edit1.text ));
S_number: = edit1.text;
S_characterlast: = '/';
I: = '';
End;

If s_characterlast = '/' then
Begin
Edit1.text: = floattostr (strtofloat (s_number)/strtofloat (edit1.text ));
S_number: = edit1.text;
S_characterlast: = '/';
I: = '';
End;
End
//**************//
Else
Begin
S_characterlast: = '/';
S_number: = edit1.text;
I: = '000000 ';
End;
J: = '000000 ';
End;

Procedure tform1.button17click (Sender: tobject );
Begin
Close;
End;

Procedure tform1.button16click (Sender: tobject );
Begin
If s_type = '1' then
If (edit1.text = '') then
Begin
Edit1.text: = edit1.text + '0 .';
S: = '000000 ';
J: = ''; End
Else
Begin
Edit1.text: = edit1.text + '.';
S: = '000000'; End
Else begin
If (j <> '') then
Begin
Edit1.text: = '';
Edit1.text: = edit1.text + '0 .';
S_type: = '1 ';
J: = '';
End else
Begin
Edit1.text: = '';
Edit1.text: = edit1.text + '.';
S_type: = '1 ';
End;
End;
End;

Procedure tform1.button11click (Sender: tobject );
Begin
// ================================================ = //
S_type: = '0 ';
If S = ''then

Application. MessageBox ('Enter the number first, 'prompt:', 0)
Else
If s_characterlast <> ''then
Begin
If s_characterlast = 'X' then
Begin
Edit1.text: = floattostr (strtofloat (s_number) * strtofloat (edit1.text ));
S_number: = edit1.text;
End;

If s_characterlast = '+' then
Begin
Edit1.text: = floattostr (strtofloat (s_number) + strtofloat (edit1.text ));
S_number: = edit1.text;
End;

If s_characterlast = '-' then
Begin
Edit1.text: = floattostr (strtofloat (s_number)-strtofloat (edit1.text ));
S_number: = edit1.text;
End;

If s_characterlast = '/' then
Begin
Edit1.text: = floattostr (strtofloat (s_number)/strtofloat (edit1.text ));
S_number: = edit1.text;
End;
End;
J: = '000000 ';
End;

Procedure tform1.formshow (Sender: tobject );
Begin
J: = '';
S_type: = '1 ';
End;

Procedure tform1.button18click (Sender: tobject );
Begin
Edit1.text: = '';
End;

End.