Project Structure

• TestCom.dpr
• TestComF.pas
• TestComF.dfm

program TestCom;

uses
  Forms,
  TestComF in 'TestComF.pas' {Form1};

{$R *.RES}

begin
  Application.Initialize;
  Application.CreateForm(TForm1, Form1);
  Application.Run;
end.

unit TestComF;

interface

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

// redeclare the server GUID
const
  Class_Number: TGUID =
  '{5B2EF181-3AAE-11D3-B9F1-00000100A27B}';

type
  TForm1 = class(TForm)
    SpinEdit1: TSpinEdit;
    Button1: TButton;
    Button2: TButton;
    SpinEdit2: TSpinEdit;
    Button3: TButton;
    Button4: TButton;
    Label1: TLabel;
    Label2: TLabel;
    Button5: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button5Click(Sender: TObject);
  private
    Num1, Num2 : INumber;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

uses
  ComObj;

procedure TForm1.FormCreate(Sender: TObject);
begin
  // create first object
  Num1 := CreateComObject (Class_Number) as INumber;
  Num1.SetValue (SpinEdit1.Value);
  Label1.Caption := 'Num1: ' + IntToStr (Num1.GetValue);
  Button1.Enabled := True;
  Button2.Enabled := True;

  // create second object
  Num2 := CreateComObject (Class_Number) as INumber;
  Label2.Caption := 'Num2: ' + IntToStr (Num2.GetValue);
  Button3.Enabled := True;
  Button4.Enabled := True;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  // change
  Num1.SetValue (SpinEdit1.Value);
  Label1.Caption := 'Num1: ' + IntToStr (Num1.GetValue);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  // increase
  Num1.Increase;
  Label1.Caption := 'Num1: ' + IntToStr (Num1.GetValue);
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  Num2.SetValue (SpinEdit2.Value);
  Label2.Caption := 'Num2: ' + IntToStr (Num2.GetValue);
end;


procedure TForm1.Button4Click(Sender: TObject);
begin
  Num2.Increase;
  Label2.Caption := 'Num2: ' + IntToStr (Num2.GetValue);
end;

procedure TForm1.Button5Click(Sender: TObject);
var
  Num3: INumber;
begin
  // create a new temporary COM object
  Num3 := CreateComObject (Class_Number) as INumber;
  Num3.SetValue (100);
  Num3.Increase;
  ShowMessage ('Num3: ' + IntToStr (Num3.GetValue));
end;

end.

object Form1: TForm1
  Left = 218
  Top = 165
  Width = 294
  Height = 244
  Caption = 'TestCom'
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'MS Sans Serif'
  Font.Style = []
  OldCreateOrder = True
  OnCreate = FormCreate
  PixelsPerInch = 96
  TextHeight = 13
  object Label1: TLabel
    Left = 40
    Top = 24
    Width = 28
    Height = 13
    Caption = 'Num1'
  end
  object Label2: TLabel
    Left = 168
    Top = 24
    Width = 28
    Height = 13
    Caption = 'Num2'
  end
  object SpinEdit1: TSpinEdit
    Left = 40
    Top = 48
    Width = 73
    Height = 22
    MaxValue = 0
    MinValue = 0
    TabOrder = 0
    Value = 22
  end
  object Button1: TButton
    Left = 40
    Top = 88
    Width = 75
    Height = 25
    Caption = '&Change'
    Enabled = False
    TabOrder = 1
    OnClick = Button1Click
  end
  object Button2: TButton
    Left = 40
    Top = 128
    Width = 75
    Height = 25
    Caption = '&Next'
    Enabled = False
    TabOrder = 2
    OnClick = Button2Click
  end
  object SpinEdit2: TSpinEdit
    Left = 168
    Top = 48
    Width = 73
    Height = 22
    MaxValue = 0
    MinValue = 0
    TabOrder = 3
    Value = 22
  end
  object Button3: TButton
    Left = 168
    Top = 88
    Width = 75
    Height = 25
    Caption = 'C&hange'
    Enabled = False
    TabOrder = 4
    OnClick = Button3Click
  end
  object Button4: TButton
    Left = 168
    Top = 128
    Width = 75
    Height = 25
    Caption = 'N&ext'
    Enabled = False
    TabOrder = 5
    OnClick = Button4Click
  end
  object Button5: TButton
    Left = 88
    Top = 176
    Width = 105
    Height = 25
    Caption = 'Compute (Num3)'
    TabOrder = 6
    OnClick = Button5Click
  end
end