unit Unit1;    interface    uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;    type
  pObj = ^TObj;
  TObj = record
     Next : PObj;
     X,Y : Byte;
     ID : DWORD;
  end;      TForm1 = class(TForm)
    ListBox1: TListBox;
    btAdd: TButton;
    btSwap: TButton;
    procedure btAddClick(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure btSwapClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;    var
  Form1: TForm1;
  pObjList : pObj=nil;    implementation    {$R *.dfm}    function NewGObj:pObj;
begin
  New(Result);
  Result^.Next := nil;
end;    procedure AddObj(var aList,aObj:pObj);
begin
   if aList=nil then
   begin
      aList:=aObj
   end else
      Addobj(aList^.Next,aObj);
end;    procedure ClearObjList(var aList:pObj);
var
   P: pObj;
begin
   P := aList;
   while aList <> nil do
   begin
     aList := aList^.Next;
     Dispose(P);
     P := aList;
  end;
end;    procedure PrintList;
var
  P: pObj;
begin
  Form1.ListBox1.Clear;
  P := pObjList;
  while P <> nil do
  begin
    Form1.ListBox1.Items.Add(IntToStr(P^.ID));
    P:=P^.Next;
  end;
end;    procedure Swap(var Obj1,Obj2:PObj);
var
   p:PObj;
   t:TObj;
begin
   //互換記憶體原始位置
   t:=Obj1^;
   Obj1^:=Obj2^;
   Obj2^:=t;
   //互換Next指標
   p:=Obj1^.Next;
   Obj1^.Next:=Obj2^.Next;
   Obj2^.Next:=p;
end;    procedure TForm1.btAddClick(Sender: TObject);
var
   i : integer;
   P : pObj;
begin
   for i:=0 to 9 do
   begin
      P:=NewGObj;
      P.ID:=random(100);
      Addobj(pObjList,P);
   end;
   PrintList;
end;    procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
   ClearObjList(pObjList);
end;    procedure TForm1.btSwapClick(Sender: TObject);
var
   i,T : integer;
begin
   T := GetTickCount;
   for i:=0 to 100000 do
   begin
      Swap(pObjList,pObjList.Next);//<==這樣會有問題0跟1對換
//      Swap(pObjList,pObjList.Next.Next);//<==這樣就不會0跟2對換
   end;
   Caption:=Caption ',' IntToStr(GetTickCount-T);
end;    end.

procedure SwappObj(var aObj1,aObj2:PObj);
var
   T1,T2 :TObj;
begin
   T1:=aObj1^;
   T1.Next:=aObj2.Next;
   T2:=aObj2^;
   T2.Next:=aObj1.Next;
   aObj1^:=T2;
   aObj2^:=T1;
end;