I have already gone through this post
for nested scrolling but it is not the correct way according to me as explained in this video from the official flutter channel
I want to achieve the below layout
The list header like Claim requested credentials,Claim received credentials,Pending Requests etc are dynamic and will be coming from backend. Also each item in those list header like Module 1: Designing Financial Services are also dynamic
So I need list within a list
I am using a CustomScroll but I am not able to achieve the inner list view
I am looking for a lazy list option and not just mapping the inner list over a column or a list as the inner list might contain 100 items
Here is what I have achieved
Here is the sample code
class MyHomePage extends StatelessWidget {
const MyHomePage({super.key});
@override
Widget build(BuildContext context) {
return Scaffold(
body: Stack(
children: [
HeaderGradient(),
Positioned(
top: 110,
left: 0,
right: 0,
bottom: 0,
child: Container(
padding: const EdgeInsets.all(8.0),
decoration: const BoxDecoration(
color: grayColor,
borderRadius: BorderRadius.only(
topLeft: Radius.circular(20),
topRight: Radius.circular(20),
),
),
child: CustomScrollView(
slivers: [
const SliverToBoxAdapter(
child: ManageCredentialHeader(),
),
SliverList(
delegate: SliverChildBuilderDelegate((context, index) {
return ManageCredentialCard();
}, childCount: 10))
],
),
),
)
],
),
);
}
}
and
class ManageCredentialCard extends StatelessWidget {
const ManageCredentialCard({super.key});
@override
Widget build(BuildContext context) {
return Card(
color: Theme.of(context).colorScheme.background,
child: Padding(
padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
child: Column(
children: [
const ManageCredentialCardHeader(),
const ManageCredentialCardItem()
],
),
),
);
}
}
ManageCredentialCardItem
is the inner list
As soon as I wrap ManageCredentialCardItem
inside a ListView.builder
I get error saying
RenderFlex children have non-zero flex but incoming height constraints are
unbounded.
When a column is in a parent that does not provide a finite height constraint,
for example if it is
in a vertical scrollable, it will try to shrink-wrap its children along the
vertical axis. Setting a
flex on a child (e.g. using Expanded) indicates that the child is to expand to
fill the remaining
space in the vertical direction.
Check the sample repo to check what I have tried and full source code
5
Answers
To solve the ‘ListView.builder’ problem, I suggest to wrap it into an ’Expanded’ and set the ’shrinkWrap’ property of the ’ListView’ to true.
As for the list inside a list problem I’m not sure I understand correctly, but setting the ’primary’ property of the inner List to false should make it so it follows the scroll of the general list and avoids scrolling internally.
It might be needed to also set the ’shrinkWrap’ to true since it has no defined height, making it not lazy, but I’d try also wrapping it with ’Expanded’ as it might have the same result keeping it lazy
As @Yeasin Sheikh suggested, you dont need to use
Listview.builder
insideManageCredentialCardItem
because the parent ofManageCredentialCardItem
is handling the scroll i.eIf you have useCase where you have to use
ListView.builder
for fetching the results from remote source, you can useshrinkWrap: true
prop insideListView.builder
I’m not really sure about what effect you want to achieve, but :
If your goal is to display the full list of items in your
ManageCredentialCard
like this:you just need to update the
ManageCredentialCard
widget with the followingBUT
If your goal is to limit the size of your
Cards
, and be able to scroll the Items list like thisyou will have to define a height limit to your Cards with a
SizeBox
.The only thing you’ll have to do then would be to scroll the main
Listview
when reaching the end of one of the inner-lists.To do so, you can use the
NotificationListener
widget as explained in this post :Flutter : ListView : Scroll parent ListView when child ListView reach bottom – ClampingScrollPhysics not working in sized container
I was referring generating everything on sliver like
Also you can create custom-sliver for children.
Use these below codes in ListView, SingleChildScrollView, ListView.builder() or any scroll view widgets.
For more, please go through this article.