DropdownButtonFormField not getting rebuilt

Question

I'm trying to update the selected value programmatically.

I've used various method, including Consumer etc., and have made sure that the value is updated and the widget is called when the value changes, however, DropdownButtonFormField never got rebuilt with the latest value.

Currently I'm wrapping the DropdownButtonFormField in a StreamBuilder, which supposedly, should get rebuild whenever there's a new event sent through the stream. This is my code:

Declaration

final StreamController<String> _raceStreamController = new StreamController<String>();

DropdownButtonFormField

return  
    StreamBuilder<String>(
      stream: _raceStreamController.stream,
      builder: (BuildContext context, AsyncSnapshot<String> snapshot) {

        return new DropdownButtonFormField<String>(
          value: snapshot.data,
          hint: new Text(hint,
            textAlign: TextAlign.center),
          isExpanded: true,
          items: items.map((String value) {
            return new DropdownMenuItem<String>(
              child: new Text(value),
              value: value
            );
          }).toList(),
          validator: (value) => value == null ? 'field required' : null,
          onChanged: (value) {} // no use for now,
      );
  });

Push data

onFocusChange: (focus) async {
  if (!focus) {
    try{
      await userBloc.searchUser(controller.text.toUpperCase());
      _raceStreamController.sink.add(userBloc.user.race);
    } catch(e) {
      if (e.toString() == ERROR_UNAUTHORISED)
        navigateToRoot(context);
    }
  }
}

I've tried to remove as much redundant code as possible.

Thank you.

Answer 1

In Flutter version 1.17.2, that DropdownButtonFormField bug was fixed, so be sure to upgrade.

Github issue: https://github.com/flutter/flutter/issues/56898

Fixed in version 1.17.2: https://github.com/flutter/flutter/wiki/Hotfixes-to-the-Stable-Channel#1172-may-28-2020