Flutter CupertinoPicker not rendering - flutter

Question

Trying to make a Flutter CupertinoPicker work on Flutter 1.7. No fancy stuff, just the basic code inside a Scaffold body...
Only using the mandatory elements...tried even sample code of other people, nothing works.
CupertinoPicker(
itemExtent: 30.0,
onSelectedItemChanged: (int idx) {
setState(() {
_prayer.rebuild((b) =>
b..category = listOfStrings[idx]);
});
},
children: List<Widget>.generate(
listOfStrings.length,
(int i) {
return Text('Dummy Text');
},
),
)
flutter: Another exception was thrown: RenderFlex children have non-zero flex but incoming height constraints are unbounded.
flutter: Another exception was thrown: RenderBox was not laid out: RenderFlex#fdf27 relayoutBoundary=up3 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
flutter: Another exception was thrown: RenderBox was not laid out: RenderFlex#052f5 relayoutBoundary=up2 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
flutter: Another exception was thrown: RenderBox was not laid out: RenderPadding#0d6c9 relayoutBoundary=up1 NEEDS-PAINT NEEDS-COMPOSITING-BITS-UPDATE
flutter: Another exception was thrown: RenderFlex children have non-zero flex but incoming height constraints are unbounded.
flutter: Another exception was thrown: RenderBox was not laid out: RenderFlex#fdf27 relayoutBoundary=up3 NEEDS-PAINT
flutter: Another exception was thrown: RenderBox was not laid out: RenderFlex#052f5 relayoutBoundary=up2 NEEDS-PAINT
flutter: Another exception was thrown: RenderBox was not laid out: RenderPadding#0d6c9 relayoutBoundary=up1 NEEDS-PAINT
flutter: Another exception was thrown: NoSuchMethodError: The method '>' was called on null.
Android Picker works...
Is there a need that the parent Widget should be Cupertino based or something ?

Answer 1

Expanded(
child:
CupertinoPicker(
backgroundColor: Colors.white,
onSelectedItemChanged: (index) {
},
itemExtent: 50.0,
children:new List<Widget>.generate(
companyList.length, (int index) {
return new Center(
child: new Text(
"${companyList[index]}",
style: TextStyle(fontSize: 16,fontFamily:
'HelveticaRegular'),),
);})
))

Answer 2

You can fix it in two ways. As the answer is in the logcat RenderFlex.
We need to provide the height either using Container
Container(
height: 200.0,
child: CupertinoPicker(
itemExtent: 30.0,
onSelectedItemChanged: (int idx) {
setState(() {
_prayer.rebuild((b) =>
b..category = listOfStrings[idx]);
});
},
children: List<Widget>.generate(
listOfStrings.length,
(int i) {
return Text('Dummy Text');
},
),
)
)
Or
Using the Expanded in case of Row and Column
Expanded(
child: CupertinoPicker(
itemExtent: 30.0,
onSelectedItemChanged: (int idx) {
setState(() {
_prayer.rebuild((b) =>
b..category = listOfStrings[idx]);
});
},
children: List<Widget>.generate(
listOfStrings.length,
(int i) {
return Text('Dummy Text');
},
),
)
)