The full page code is very long but my DropdownButton widget code like this.
The problems are,
first: I can't update my selectedCity, it doesn't get an update. Also, the print function calls null, since my cityList data is like [new york, paris, london] etc...
second: flutter doesn't change focus from any TextField to DropdownButton fully. I mean, clicked TextField, then DropdownButton but focus reverts to that TextField after the button click. It is default action of Flutter?
List<dynamic> _cityList;
String _selectedCity;
#override
Widget build(BuildContext context) {
return DropdownButton(
value: _selectedCity,
style: TextStyle(
fontSize: 11,
color: textColor,
),
items: _cityList.map((city) {
return DropdownMenuItem<String>(
child: Padding(
padding: const EdgeInsets.only(left: 4),
child: Text(city),
),
);
}).toList(),
onChanged: (String value) {
setState(() {
_selectedCity = value;
print(_selectedCity);
});
},
isExpanded: true,
);
}
Edit: The solution of resetting FocusNode after selecting an item from DropdownMenuItem is adding this line inside of setstate like this:
this: FocusScope.of(context).requestFocus(new FocusNode());
to here: onChanged:(){setSate((){here}}
I hope it will help you. I have modified your code a little bit
List<dynamic> _cityList;
String _selectedCity;
It will show the Dropdown Button and when you click on it and select any value showing in the print
#override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
body: ListView(
children: [
Column(
children: <Widget>[
DropdownButton<String>(
items: _cityList.map((dynamic value) {
return DropdownMenuItem<String>(
value: value,
child: new Text(value),
);
}).toList(),
onChanged: (value) {
setState(() {
_selectedCity = value;
print(_selectedCity);
});
},
),
],
),
],
),
);
}
for the focus problem you should use focusNodes one with the drop down list and another with the text field https://docs.flutter.io/flutter/widgets/FocusNode-class.html.
I've added a list element by using the following method:
listToAddTo.add(italianFood());
However, when I try removing the same element by using the method:
listToAddTo.remove(italianFood());
it does not work.
I've tried using the removeWhere method with the parameters item == italianFood(), the retainWhere method with the item != italianFood() parameters, and the removeAt method with the listToAddTo.indexOf(italianFood()) parameters, however, none of those seem to work.
When I try printing the list, I get the following result:`
ListView(
scrollDirection: vertical,
primary: using primary controller,
scrollPhysics: AlwaysScrollableScrollPhysics,
shrinkWrap: shrink-wrapping
)
Above methods with this result also seem to have no effect.
Necessary code is as follows:
List listToAddTo = [];
ListView italianFood() {
return ListView(
shrinkWrap: true,
children: <Widget>[
listEntry(
'Fast Food Nana',
'Mon - Sun 06:00 - 04:00',
Container(
child: IconButton(
icon: Icon(
Icons.motorcycle,
size: 30.0,
),
),
),
IconButton(
icon: Icon(
Icons.navigation,
size: 30.0,
),
),
),
],
);
Container filterItem(String label, value, onChanged) {
return Container(
decoration: BoxDecoration(color: Colors.white),
child: CheckboxListTile(
value: value,
title: Text(label),
onChanged: onChanged,
),
);
bool isTrue = false;
Widget build(BuildContext context) {
return Stack(
children: <Widget>[
Container(
margin: const EdgeInsets.only(top: 45.0),
child: ListView.builder(
itemCount: listToAddTo.length,
itemBuilder: (BuildContext context, int Index) {
return (listToAddTo[Index]);
},
),
),
ExpansionTile(
title: Text('Filters'),
children: <Widget>[
filterItem(
'Italian',
isTrue,
(bool value) {
setState(() {
if (isTrue == false) {
listToAddTo.add(italianFood());
isTrue = !isTrue;
} else {
listToAddTo.removeAt(listToAddTo.indexOf(italianFood()));
isTrue = !isTrue;
}
});
print(listToAddTo);
print(italianFood());
},
),
],
),
],
);
You can't remove it because are different objects.
Every time you use italianFood() you create a new instance of the class.
Create a gloval variable :
ListView _myItalianFood;
Instantiate:
in your add method:
_myItalianFood = italianFood();
listToAddTo.add(_myItalianFood);
Remove:
listToAddTo.remove(_myItalianFood);
The problem is that italianFood() returns a new ListView instance on each call. So when you call listToAddTo.add(italianFood()) you are creating a new ListView instance (let's call it LV1) and you end up with listToAddTo being [LV1].
When you call listToAddTo.remove(italianFood()) you are creating a new ListView instance (let's call it LV2) and asking listToAddTo to remove anything that is equal to LV2, so this ends up doing nothing since LV2 is not in listToAddTo.
You could fix this by making italianFood a field.
final italianFood = ListView(shrinkWrap: true, ...);
I've recently started programming using dart and flutter and everything has been going smoothly for my app, although recently i wanted to add drop down menu to provide the user with multiple options to pick from. everything worked as planned however when i pick a value from the list it doesn't change the value in the box, it goes back to the hint or an empty box. any help would be appreciated!
here is my code for the dropdownbutton:
Widget buildDropdownButton() {
String newValue;
return new Padding(
padding: const EdgeInsets.all(24.0),
child: new Column(
mainAxisAlignment: MainAxisAlignment.start,
children: <Widget>[
new ListTile(
title: const Text('Frosting'),
trailing: new DropdownButton<String>(
hint: Text('Choose'),
onChanged: (String changedValue) {
newValue=changedValue;
setState(() {
newValue;
print(newValue);
});
},
value: newValue,
items: <String>['None', 'Chocolate', 'Vanilla', 'ButterCream']
.map((String value) {
return new DropdownMenuItem<String>(
value: value,
child: new Text(value),
);
}).toList()),
),
],
),
);
}
The error is because you are declaring a method variable newValue you must declare that variable as global inside your StatefulWidget.
String newValue;
Widget buildDropdownButton() {
return new Padding(
padding: const EdgeInsets.all(24.0),
child: new Column(
mainAxisAlignment: MainAxisAlignment.start,
children: <Widget>[
new ListTile(
title: const Text('Frosting'),
trailing: new DropdownButton<String>(
hint: Text('Choose'),
onChanged: (String changedValue) {
newValue=changedValue;
setState(() {
newValue;
print(newValue);
});
},
value: newValue,
items: <String>['None', 'Chocolate', 'Vanilla', 'ButterCream']
.map((String value) {
return new DropdownMenuItem<String>(
value: value,
child: new Text(value),
);
}).toList()),
),
],
),
);
}
Faced same issue and none of the answers worked. Then, I found the solution in one of my old projects.
I was using it in a AlertDialog here.
So, Change DropdownButton to DropdownButtonFormField
and add onSaved exactly as onChanged:
onSaved: (value) {
setState(() {
_selectedValue = value;
});
}
That's it. It will start working.
I had this problem although I was already using the solution above.
for anyone who has this problem and the above solution does not work, try separating FutureBuilder from the dropdown. this is how your final code should look like:
class TheFuture extends StatelessWidget {
#override
Widget build(BuildContext context) {
return FutureBuilder(
future: myFuture(),
builder: (ctx, snp) {
if (!snp.hasData) return LoadingLine();
return TheBuilder(snp.data);
},
);
}
}
class TheBuilder extends StatefulWidget {
const TheBuilder(this.mp);
final Map<String, dynamic> mp;
#override
_MessageUSScreenFilterBodyState createState() =>
_MessageUSScreenFilterBodyState();
}
class _MessageUSScreenFilterBodyState extends State<MessageUSScreenFilterBody> {
int _selectedId;
#override
Widget build(BuildContext context) {
return DropdownButton<int>(
selectedItemBuilder: (context) =>
widget.mp['myData'].map((e) => Text(e.type)).toList(),
items: widget.mp['myData']
.map(
(e) => DropdownMenuItem(
child: Text(e.type),
value: e.id,
),
)
.toList(),
value: _selectedId,
onChanged: (int _id) {
setState(() {
_selectedId = _id;
});
},
);
}
}
wrap dropdown button with StatefulBuilder and initialise newValue outside build method.
StatefulBuilder(
builder: (context, setState) => AlertDialog(
title: Text("Change Status"),
content: Container(
padding: EdgeInsets.symmetric(horizontal: 8.0),
decoration: BoxDecoration(
border: Border.all(color: Colors.grey, width: 1),
borderRadius: BorderRadius.circular(5)),
child: DropdownButtonHideUnderline(
child: DropdownButton(
hint: Text('Choose'),
onChanged: (String changedValue) {
setState(() {
newValue = changedValue;
print(newValue);
});
},
value: newValue,
items: <String>[
'None',
'Chocolate',
'Vanilla',
'ButterCream'
].map((String value) {
return new DropdownMenuItem<String>(
value: value,
child: new Text(value),
);
}).toList()),
),
),
),
));
I am pretty new to Flutter and Dart and I can't seem to find any hints for this particular topic. I am trying to put 3 RadioListTiles in a Row like so:
Row(
children: [
Expanded(
child:RadioListTile<GoalSelection>(
title: Text(
'Net',
style: Theme.of(context).textTheme.body1,
),
value: GoalSelection.net,
groupValue: _goalSelection,
onChanged: (GoalSelection value) {
setState(() {
_goalSelection = value;
});
},
),
),
Expanded(
child: RadioListTile<GoalSelection>(
title: Text(
'Gross',
style: Theme.of(context).textTheme.body1,
),
value: GoalSelection.gross,
groupValue: _goalSelection,
onChanged: (GoalSelection value) {
setState(() {
_goalSelection = value;
});
},
),
),
Expanded(
child: RadioListTile<GoalSelection>(
title: Text(
'Salary',
style: Theme.of(context).textTheme.body1,
),
value: GoalSelection.salary,
groupValue: _goalSelection,
onChanged: (GoalSelection value) {
setState(() {
_goalSelection = value;
});
},
),
),
],
),
The buttons layout fine, but there seems to be a lot of wasted space for the label. I put a screenshot of what it currently looks like below. I have tried wrapping the Expanded, the RadioListTile, and the Text in Padding widgets (all one at a time) to manually set the padding to 0, but it didn't do anything. I have also tried to change Expanded to Flexible even though I didn't think that would change anything. I am at a loss now. Is there any way to get this layout to work? I am kind of assuming it is something really dumb that I am doing.
You can use Radio + text widget instead of RadioListTile. For removing internal padding in Radio widget set:
Radio(
visualDensity: const VisualDensity(
horizontal: VisualDensity.minimumDensity,
vertical: VisualDensity.minimumDensity),
materialTapTargetSize: MaterialTapTargetSize.shrinkWrap,
.....
),
You can use a Radio and Text widget in a row. But the Radio also has the same padding problem. To remove the padding you can put the Radio as a child of a SizedBox.
eg:- SizedBox(height: 20, width: 20, child: Radio(.......))
RadioListTile is used with the purpose of taking the full width in a vertical scroll list.
If you don't want this behavior, don't use it. Use Radio instead.
just set contentPadding: EdgeInsets.zero
RadioListTile(contentPadding: EdgeInsets.zero)
We can control the padding of the RadioListTile using Flexible widget. As you want to arrange 3 RadioListTiles inside a Row Widget. Please try with the below code, it will work.
Row(
children: <Widget>[
Flexible(
fit: FlexFit.loose,
child:
RadioListTile(
title: const Text('hello'),
onChanged: (value) {
setState(() {});
},
),
),
Flexible(
fit: FlexFit.loose,
child:
RadioListTile(
title: const Text('Lafayette'),
onChanged: (value) {
setState(() {});
},
),
)
],
),
Do, let me know. Once you tried with the above code. If it resolved you problem, please accept my answer as useful and provide your valuable comments.
I got the same problem. You could try to customize with Radio, Text, InkWell, Padding.
class LabeledRadio extends StatelessWidget {
const LabeledRadio({
this.label,
this.padding,
this.groupValue,
this.value,
this.onChanged,
});
final String label;
final EdgeInsets padding;
final bool groupValue;
final bool value;
final Function onChanged;
#override
Widget build(BuildContext context) {
return InkWell(
onTap: () {
if (value != groupValue)
onChanged(value);
},
child: Padding(
padding: padding,
child: Row(
children: <Widget>[
Radio<bool>(
groupValue: groupValue,
value: value,
onChanged: (bool newValue) {
onChanged(newValue);
},
),
Text(label),
],
),
),
);
}
}
// ...
bool _isRadioSelected = false;
#override
Widget build(BuildContext context) {
return Scaffold(
body: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <LabeledRadio>[
LabeledRadio(
label: 'This is the first label text',
padding: const EdgeInsets.symmetric(horizontal: 5.0),
value: true,
groupValue: _isRadioSelected,
onChanged: (bool newValue) {
setState(() {
_isRadioSelected = newValue;
});
},
),
LabeledRadio(
label: 'This is the second label text',
padding: const EdgeInsets.symmetric(horizontal: 5.0),
value: false,
groupValue: _isRadioSelected,
onChanged: (bool newValue) {
setState(() {
_isRadioSelected = newValue;
});
},
),
],
),
);
}
The documentation: https://api.flutter.dev/flutter/material/RadioListTile-class.html#material.RadioListTile.3
This is how I fix the padding:
enum ContactSex { nam, nu, khac }
class CreateContactScreen extends StatefulWidget {
static const routeName = './create_contact';
#override
_CreateContactScreenState createState() => _CreateContactScreenState();
}
class _CreateContactScreenState extends State<CreateContactScreen> {
ContactSex _contaxtSex = ContactSex.nu;
final _form = GlobalKey<FormState>();
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(
'TẠO LIÊN HỆ',
style: kHeaderTextStyle,
),
actions: <Widget>[
FlatButton(
onPressed: () {
Navigator.pop(context);
},
child: Text('XONG', style: TextStyle(color: Colors.white),),
)
],
),
body: Container(
padding: EdgeInsets.symmetric(horizontal: 15.0, vertical: 20.0),
child: Form(
key: _form,
child: SingleChildScrollView(
child: Column(
children: <Widget>[
TextFormField(
decoration: InputDecoration(
labelText: 'Tên*',
),
textInputAction: TextInputAction.next,
onFieldSubmitted: (_) {
// TODO: when submit this text field
},
validator: (value) {
if (value.isEmpty) {
return 'Hãy nhập tên cho liên hệ.';
}
return null;
},
onSaved: (value) {
// TODO : when save the whole form
},
),
TextFormField(
decoration: InputDecoration(
labelText: 'Họ',
),
textInputAction: TextInputAction.next,
onFieldSubmitted: (_) {
// TODO: when submit this text field
},
// validator: (value) {
// if (value.isEmpty) {
// return null;
// }
// return null;
// },
onSaved: (value) {
// TODO : when save the whole form
},
),
TextFormField(
decoration: InputDecoration(
labelText: 'Số điện thoại*',
),
keyboardType: TextInputType.phone,
textInputAction: TextInputAction.next,
onFieldSubmitted: (_) {
// TODO: when submit this text field
},
validator: (value) {
if (value.isEmpty) {
return 'Hãy nhập số điện thoại cho liên hệ.';
}
return null;
},
onSaved: (value) {
// TODO : when save the whole form
},
),
TextFormField(
decoration: InputDecoration(
labelText: 'Email',
),
textInputAction: TextInputAction.next,
onFieldSubmitted: (_) {
// TODO: when submit this text field
},
// validator: (value) {
// if (value.isEmpty) {
// return null;
// }
// return null;
// },
onSaved: (value) {
// TODO : when save the whole form
},
),
Container(
padding: EdgeInsets.only(top: 15.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(
'Giới tính',
style: TextStyle(fontSize: 14.0),
),
Row(
mainAxisSize: MainAxisSize.max,
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
LabeledRadio(
label: 'Nữ',
padding: EdgeInsets.all(0),
groupValue: _contaxtSex,
value: ContactSex.nu,
onChanged: (ContactSex newValue) {
setState(() {
_contaxtSex = newValue;
});
},
),LabeledRadio(
label: 'Nam',
padding: EdgeInsets.all(0),
groupValue: _contaxtSex,
value: ContactSex.nam,
onChanged: (ContactSex newValue) {
setState(() {
_contaxtSex = newValue;
});
},
),LabeledRadio(
label: 'Khác',
padding: EdgeInsets.all(0),
groupValue: _contaxtSex,
value: ContactSex.khac,
onChanged: (ContactSex newValue) {
setState(() {
_contaxtSex = newValue;
});
},
),
],
),
],
),
)
],
)),
),
),
);
}
}
class LabeledRadio extends StatelessWidget {
final String label;
final EdgeInsets padding;
final ContactSex groupValue;
final ContactSex value;
final Function onChanged;
const LabeledRadio(
{this.label, this.padding, this.groupValue, this.value, this.onChanged});
#override
Widget build(BuildContext context) {
return InkWell(
onTap: () {
if (value != groupValue) {
onChanged(value);
}
},
child: Padding(
padding: padding,
child: Row(
children: <Widget>[
Radio<ContactSex>(
groupValue: groupValue,
value: value,
onChanged: (ContactSex newValue) {
onChanged(newValue);
},
),
Text(label),
],
),
),
);
}
}
You just need to set the "dense" property to true, example:
RadioListTile<String>(
title: "My radio",
dense: true, // <= here it is !
value: '1',
);
you should achieve this manually like
make a group of Radio() and Text() and wrap with InkWell() for state handling. now remove extra space of radio by materialTapTargetSize: MaterialTapTargetSize.shrinkWrap, That's it. Get idea by sample code.
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
InkWell(
onTap: () {
setState(() {
_radioVenue = 0;
});
},
child: Row(
children: [
Radio(
materialTapTargetSize:
MaterialTapTargetSize.shrinkWrap,
activeColor: primaryColor,
groupValue: _radioVenue,
onChanged: (value) {},
value: 0,
),
Text('From our list')
],
),
),
InkWell(
onTap: () {
setState(() {
_radioVenue = 1;
});
},
child: Row(
children: [
Radio(
materialTapTargetSize:
MaterialTapTargetSize.shrinkWrap,
activeColor: primaryColor,
groupValue: _radioVenue,
onChanged: (value) {},
value: 1,
),
Text('From our list')
],
),
),
],
),
We covered both both the issues in this sample.
Removed extra spaces.
whole group is selectable radio + text, Now it behaves like RadioListTile().
Simply use RadioListTile and remove extra padding, by default it's 18
RadioListTile(contentPadding: EdgeInsets.symmetric(horizontal: 0.0)),
OR
RadioListTile(
contentPadding: EdgeInsets.symmetric(horizontal: 0.0),
value: null,
groupValue: null,
onChanged: null,
),
glad to answer
I was looking for same question and ended up on Flutter Documentation
I was working on Column and RadioListTile and I faced same issue, there's a horizontal padding between content inside RadioListTile
So, here it's the answer
Looking for this documentation ! RadioListTile content padding
Just add contentPadding: EdgeInsets.symmetric(horizontal: 0) and here you go, there's no horizontal padding anymore
Just copy paste this code and enjoy
Container(
height:35,
child: Row(
children: [
Radio(
groupValue: data.selected,
value: e,
onChanged: (DataBindModel? value) {
listener.value = MultiChoiceData(selected: value, items: listener.value.items);
onChanged(value);
onSelected(value);
},
),
Text(
e.value,
style: body14,
)
],
),
)
Copy the RadioListTile code and create your on new new file and paste it in there.
Remove the imports causing errors:
import 'package:flutter/widgets.dart'; // leave it
import 'package:flutter/material.dart'; //add
import 'list_tile.dart'; //remove
import 'radio.dart'; //remove
import 'theme.dart'; //remove
import 'theme_data.dart'; //remove
Then add the following padding to it, like this:
//Inside the file locate this widget and Add the padding or remove it. I needed to remove it and add 5.
return MergeSemantics(
child: ListTileTheme.merge(
contentPadding: EdgeInsets.only( // Add this
left: 5,
right: 0,
bottom: 0,
top: 0
),
selectedColor: activeColor ?? Theme.of(context).accentColor,
child: ListTile(
leading: leading,
title: title,
subtitle: subtitle,
trailing: trailing,
isThreeLine: isThreeLine,
dense: dense,
enabled: onChanged != null,
onTap: onChanged != null && !checked ? () { onChanged(value); } : null,
selected: selected,
),
),
);
then Import the file into your project like this:
import 'package:Project_Name/common/customComponets/custom_radio_list_tile.dart' as CustomRadioListTile;
Then use it like this:
CustomRadioListTile.RadioListTile(); // and that's how I managed to do it. Thought I should share.
This is my way of reducing the space. I have three Radio in one row.
Row(
children: [
Expanded(
child: RadioListTile(
contentPadding: EdgeInsets.all(0.0),
value: DayoffType.Range,
groupValue: _dayoffType,
title: Transform.translate(offset: const Offset(-18, 0), child: Text('Range')),
onChanged: (DayoffType? val) {
setState(() {
_dayoffType = val!;
});
},
),
),
Expanded(...Radio2...),
Expanded(...Radio3...)
)