字节的合并

unit unit1;

interface

uses
  winapi.windows, winapi.messages, system.sysutils, system.variants, system.classes, vcl.graphics,
  vcl.controls, vcl.forms, vcl.dialogs, vcl.stdctrls;

type
  tform1 = class(tform)
    btn1: tbutton;
    btn2: tbutton;
    procedure formcreate(sender: tobject);
    procedure btn1click(sender: tobject);
    procedure btn2click(sender: tobject);
  private
    { private declarations }
  public
    { public declarations }
  end;

var
  form1: tform1;

implementation

{$r *.dfm}

type
  t4byterec = packed record
    case integer of
    0:
    (
     b1,b2,b3,b4: byte ;
    );
    1:
    (
     bs:array [0..3] of byte ;
    );
    2:
    (
      //x64:int64;  //x64 是8位
      x64:integer;
    );
  end;

procedure tform1.btn1click(sender: tobject);
var
  arec: t4byterec ;
  t:array[0..3] of byte;
  pint:pinteger;
begin
  arec.b1 :=$1;
  arec.b2:=$2;
  arec.b3 :=$3 ;
  arec.b4 :=$4;

  showmessage( inttohex(integer(arec.x64),4)) ;
end ;


procedure tform1.btn2click(sender: tobject);
var
  n1,n2: cardinal;
  num64: int64;
  rec: int64rec;
begin

  n1 := $44332211;
  n2 := $aabbccdd;
  rec.lo := n1;
  rec.hi := n2;
  num64 := int64(rec);
  showmessage(inttohex(num64, 0)); //aabbccdd44332211
end;

procedure tform1.formcreate(sender: tobject);
var
  p1:pshortint;
  p2:psmallint;

  b1:array[0..0] of byte;
  b2:array[0..1] of byte;
begin
  inttohex(-1,4);
  strtoint('$ffff');

  b1[0]:= $ff;

  b2[0]:= $ff;
  b2[1]:=$ff;

  p1:=@b1[0];
  p2:=@b2[0];

  //showmessage(inttostr(p1^));
 // showmessage(inttostr(p2^));
end;

end.