How can i smoothly scroll between NestedScrollView and ListView.builder - flutter

Question

I have the following simple full code ..
import 'package:flutter/material.dart';
class Profile extends StatefulWidget {
const Profile({ Key? key, }) : super(key: key);
#override
ProfileState createState() => ProfileState();
}
class ProfileState extends State<Profile>{
#override
Widget build(BuildContext context) {
return SafeArea(
child: NestedScrollView(
headerSliverBuilder: (context,value){
return[
const SliverAppBar(
expandedHeight: 400,
)
];
},
body: ListView.builder(
itemCount: 200,
itemBuilder: (BuildContext context, int index) {
return Center(child: Text(index.toString()));
},
)
),
);
}
}
in the previous code, everything is ok and it shifted the scroll in a smooth way BUT when I provide ScrollController into my ListView.builder the scroll is no longer smooth anymore.
so Please How could I keep the first result (with no providing ScrollController) the same as (with providing ScrollController)? .

Answer 1

I recreated your requirements using CustomScrollView, the API is "harder" to use but it allows you implement more complex features (like nested scrollviews as you are doing) because we have direct access to the Slivers API.
You can see that almost any Flutter scrollable widget is a derivation of either CustomScrollView or ScrollView which makes use of Slivers.
NestedScrollView is a subclass of CustomScrollView.
ListView and GridView widgets are subclasses of ScrollView.
Although seems complicated a Sliver is just a portion of a scrollable area:
CustomScrollView(
controller: _scrollController,
slivers: [
const SliverAppBar(expandedHeight: 400),
SliverList(
delegate: SliverChildBuilderDelegate(
(context, index) {
return Center(child: Text('item $index.'));
},
),
),
],
)
So, instead of creating multiple scrollviews and trying to mix them together (which lead to buggy behaviors), just declare multiple scrollable areas and put them together inside a CustomScrollView, that's it.
See the working example at: https://dartpad.dev/?id=60cb0fa073975f3c80660815ae88af4e.