flutter-widget

问题 I am battling this DropDownItem box error, everything seems to work, but pops up the yellow out of bounds while it loads. Tried several things and can not get it resolved. I have this code for my Widget . @override Widget build(BuildContext context) { var _children = <Widget>[ !_createNew ? _referrerPractice() : _referrerCreate(), ]; return new Scaffold( appBar: new AppBar( title: new Text(widget.title), ), body: new Column( mainAxisSize: MainAxisSize.max, children: _children, )); } I then

问题 I am battling this DropDownItem box error, everything seems to work, but pops up the yellow out of bounds while it loads. Tried several things and can not get it resolved. I have this code for my Widget . @override Widget build(BuildContext context) { var _children = <Widget>[ !_createNew ? _referrerPractice() : _referrerCreate(), ]; return new Scaffold( appBar: new AppBar( title: new Text(widget.title), ), body: new Column( mainAxisSize: MainAxisSize.max, children: _children, )); } I then

问题 I am battling this DropDownItem box error, everything seems to work, but pops up the yellow out of bounds while it loads. Tried several things and can not get it resolved. I have this code for my Widget . @override Widget build(BuildContext context) { var _children = <Widget>[ !_createNew ? _referrerPractice() : _referrerCreate(), ]; return new Scaffold( appBar: new AppBar( title: new Text(widget.title), ), body: new Column( mainAxisSize: MainAxisSize.max, children: _children, )); } I then

问题 I am battling this DropDownItem box error, everything seems to work, but pops up the yellow out of bounds while it loads. Tried several things and can not get it resolved. I have this code for my Widget . @override Widget build(BuildContext context) { var _children = <Widget>[ !_createNew ? _referrerPractice() : _referrerCreate(), ]; return new Scaffold( appBar: new AppBar( title: new Text(widget.title), ), body: new Column( mainAxisSize: MainAxisSize.max, children: _children, )); } I then

问题 I am trying to fetch data from Friebase-firestore and then convert it to model, I used the same code and approach to another project (web project) ,it works fine , but with this project it doesn't work ,I don't know why. I upgrade flutter version, run Flutter doctor , and nothing wrong with the environment setup. here is the code : class dbService{ static final CollectionReference myCollection = FirebaseFirestore.instance.collection('myCollection'); static Future<myModel> getMyInfo() async{

问题 I am trying to read the data from firebase after scanning a barcode. This is how it should appear, but instead of barcode, it should display name and price from the database (https://m.imgur.com/gallery/lEFJZ0Q) Code: class ListTileModel { String barcode; ListTileModel(this.barcode); } the below code is inside the stateful widget List<ListTileModel> _items = []; String barcode = ""; void _add() { _items.add(ListTileModel(barcode)); setState(() {}); } @override void initState(){ super

问题 I am using nested stream and a timer method for my app. Which is like a display board changes values (or screen) in every 10 seconds and repeat. I have not any quite idea about the problems in my code (it just seems working well), also thinking to add a clock in my screen, which am not sure how to implement yet (using stream again or with initstate ). Please check my main code and give me some tips to clean up any issues if there. My app is using firebase to get latest data. class OmApp

问题 In my flutter app, I have a ConnectivityStatus widget which displays the current connection status of the app to my raspberry pi. In the initState of my widget, I subscribe to a timer to check the connection every 5 seconds and update the state accordingly, then unsubscribe upon disposal. The issue is, when multiple screens use the ConnectivityStatus widget, such as in a stack navigator setup, I now have two concurrent subscriptions as neither instance has disposed. This causes many redundant

问题 How can I add a validator function to a list of RadioButtons in order to have them validated (like TextFormFields with _formKey.currentState.validate() ) after the User submits the Form ? 回答1: You can copy paste run full code below You can use package https://pub.dev/packages/flutter_form_builder It support bulid-in validators such as FormBuilderValidators.required() you can directly use you can also use custom validator function https://pub.dev/packages/flutter_form_builder#custom-validator

问题 How can I add a validator function to a list of RadioButtons in order to have them validated (like TextFormFields with _formKey.currentState.validate() ) after the User submits the Form ? 回答1: You can copy paste run full code below You can use package https://pub.dev/packages/flutter_form_builder It support bulid-in validators such as FormBuilderValidators.required() you can directly use you can also use custom validator function https://pub.dev/packages/flutter_form_builder#custom-validator