bases.pas

《Kylix程序设计》一书中附带的例程源代码

unit Bases;

interface

uses
  SysUtils, Classes, Types, QGraphics;

type
  TA = class( TObject )
  public
    FA: Integer;
  public
    function Do1(): Integer;
  end;

  TB = class( TA )
//  protected
  public
    FB: Integer;
  public
    function Do2(): Integer;
    function Do1(): Integer;  // Declare this, get chap1102.bmp
    // The Reserved word, overload, has no any effects to Do1. 
  end;

  TC = class( TB )
//  protected
  public
    FC: Integer;
  public
    function Do3(): Integer; overload;
  end;

var
  A: TA;
  B: TB;
  pm, pn: function (): Integer of object;

implementation

{ TA }

function TA.Do1(): Integer;
begin
  // This gets the address Self points to, i.e., the object per se.
  Result := Integer( Pointer( Self ) );
  // if use
  // Result := Integer( @Self );
  // we will get the the address of Self per se.
end;

{ TB }

function TB.Do1: Integer;
begin
  Result := Inherited Do1;
end;

function TB.Do2(): Integer;
begin
  Result := Integer( Pointer( Self ) );
end;

{ TC }

function TC.Do3(): Integer;
begin
  Result := Integer( Pointer( Self ) );
end;

end.