// Compare TIcons example.
// efg, www.efg2.com/Lab
// September 2000

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation
{$R *.DFM}

  FUNCTION AreIconsEqual(CONST Icon1, Icon2:  TIcon):  BOOLEAN;
    VAR
      m1:  TMemoryStream;
      m2:  TMemoryStream;
  BEGIN
    RESULT := FALSE;

    m1 := TMemoryStream.Create;
    TRY
      Icon1.SaveToStream(m1);

      m2 := TMemoryStream.Create;
      TRY
        Icon2.SaveToStream(m2);

        IF   m1.Size = m2.Size
        THEN RESULT := CompareMem(m1.Memory, m2.Memory, m1.Size)
      FINALLY
        m2.Free
      END
    FINALLY
      m1.Free
    END
  END {AreTIconsEqual};

procedure TForm1.Button1Click(Sender: TObject);
  VAR
    iconA:  TIcon;
    iconB:  TIcon;
    iconC:  Ticon;
begin
  iconA := TIcon.Create;
  iconB := TIcon.Create;
  iconC := TIcon.Create;
  TRY
    iconA.LoadFromFile('A.ICO');
    iconB.LoadFromFile('B.ICO');   // A <> B
    iconC.LoadFromFile('C.ICO');   // A  = C

    IF   AreIconsEqual(iconA, iconB)
    THEN ShowMessage('A and B match')
    ELSE ShowMessage('A and B do not match');

    IF   AreIconsEqual(iconA, iconC)
    THEN ShowMessage('A and C match')
    ELSE ShowMessage('A and C do not match');

    IF   AreIconsEqual(iconB, iconC)
    THEN ShowMessage('B and C match')
    ELSE ShowMessage('B and C do not match');

  FINALLY
    iconA.Free;
    iconB.Free;
    iconC.Free
  END

end;

end.