@Override
 public void onActivityResult(int requestCode, int resultCode, Intent data) {
   if (resultCode == Activity.RESULT_OK && requestCode == request_code_scanner) {
     String code = ZXScanHelper.getScannedCode(data);
     compareCode(code);
   }
 }
 private void doScanQRCode() {
   if (Home.instance != null) {
     Home.instance.setPause(false);
     ZXScanHelper.scan(Home.instance, request_code_scanner);
   }
 }