//加入nb30.pas单元

var
  LanaNum: Byte;
  MACAddress: PMACAddress;
  RetCode: Byte;
begin
  LanaNum := StrToInt(ComboBox1.Text);
  New(MACAddress);
  try
    RetCode := GetMACAddress(LanaNum, MACAddress);
    if RetCode = NRC_GOODRET then
    begin
      Edit1.Text := Format('%2.2x-%2.2x-%2.2x-%2.2x-%2.2x-%.2x', MACAddress[0], MACAddress[1], MACAddress[2], MACAddress[3], MACAddress[4], MACAddress[5]]);
    end else
    begin
      Beep;
      Edit1.Text := 'Error';
      ShowMessage('GetMACAddress Error! RetCode = $' + IntToHex(RetCode, 2));
    end;
  finally
    Dispose(MACAddress);
  end;

（出处：DelphiFans.com）