链表测试

  PMyList = ^TMyList;
  TMyList = record
    Text: string;
    Previous: PMyList;
    Next: PMyList;
  end;

var
    FHead: PMyList;
    FLast: PMyList;
    CurrIndex: Integer;
    FList: TList;

procedure TForm1.btn_1Click(Sender: TObject);
begin
  //创建链表头
  GetMem(FHead, SizeOf(TMyList));
  FHead.Text := Edit1.Text;
  FHead.Previous := nil;
  FHead.Next := nil;
  FLast := FHead;
end;

procedure TForm1.btn_2Click(Sender: TObject);
var
  vCur: PMyList;
begin
  //添加新元素
  GetMem(vCur, SizeOf(TMyList));
  vCur.Text := Edit1.Text;
  FLast.Next := vCur;
  vCur.Previous := FLast;
  vCur.Next := nil;
  FLast := vCur;
end;

procedure TForm1.btn_3Click(Sender: TObject);
var
  vCur: PMyList;
begin
  //显示所有元素
  mmo1.Clear;
  vCur := FHead;
  while vCur <> nil do
  begin
    mmo1.Lines.Add(vCur.Text);
    vCur := vCur.Next;
  end;
end;

procedure TForm1.btn_4Click(Sender: TObject);
var
  vCur: PMyList;
begin
  mmo1.Clear;
  vCur := FLast;
  //反显所有元素
  while vCur <> nil do
  begin
    mmo1.Lines.Add(vCur.Text);
    vCur := vCur.Previous;
  end;
end;

procedure TForm1.btn_5Click(Sender: TObject);
var
  vCur, p: PMyList;
begin
  //销毁链表
  p := FHead;
  while p <> nil do
  begin
    vCur := p;
    p := vCur.Next;
    FreeAndNil(vCur);
  end;
end;