procedure TForm1.Button1Click(Sender: TObject);
var
  nXMLDoc: IXMLDocument;
  i: Integer;
  nMS: TMemoryStream;
  nSS: TStringStream;
  nStr: string;
begin
  nXMLDoc := TXMLDocument.Create(nil);
  nXMLDoc.Active := True;
  nXMLDoc.Encoding := 'GB2312';
  nXMLDoc.AddChild('test');
  for i := 0 to 4 do
    nXMLDoc.DocumentElement.AddChild('测试').NodeValue := i;
  with Memo1 do
  begin
    Lines.Clear;
    Lines.Add('---- nXMLDoc.XML.Text ----');
    Lines.Add('');
    Lines.Add(nXMLDoc.XML.Text);
  end;
  nMS := TMemoryStream.Create;
  nXMLDoc.SaveToStream(nms);
  nms.Position := 0;
  with Memo2 do
  begin
    Lines.Clear;
    Lines.LoadFromStream(nms);
    Lines.Insert(0, '');
    Lines.Insert(0, '---- nXMLDoc.SaveToStream ----');
  end;
  nMS.Free;
  nXMLDoc.SaveToXML(nStr);
  with Memo3 do
  begin
    Lines.Clear;
    Lines.Add('---- nXMLDoc.SaveToXML ----');
    Lines.Add('');
    Lines.Add(nStr);
  end;
end;