flickr_request_token.dart

flickr_request_token.dart

  TextEditingController _textFieldController = TextEditingController();
  
  
  @override
  Widget build(BuildContext context) {
  ...
  ...
          AlertDialog(
            title: Text('Input verification code'),
            content: TextField(
              controller: _textFieldController,
            ),
            actions: <Widget>[
              new FlatButton(
                child: Text('OK'),
                onPressed: () {
                  client.requestToken(_textFieldController.text).then((authClient) =>
                      client.search()
                  );
                },
              )
            ],
          )
 ...
 }