Scroll controller is not attached to any scroll views - dart

Question

I am attaching scrollController to a listView builder. I am controlling scrolling using Slider.B ut I am getting error "Scroll controller is not attached to any scroll views".If I set max of Slider to some static value error is gone but if i set max = scrollController.position.maxScrollExtent it gives error.
scrollController = ScrollController(initialScrollOffset: 0.0);
scrollController.addListener(scrollListener);
Container(
decoration: BoxDecoration(color: Colors.black),
height: MediaQuery.of(context).size.height,
width: MediaQuery.of(context).size.width,
child: ListView.builder(
controller: scrollController,
scrollDirection: Axis.horizontal,
itemCount: totalSegments,
itemBuilder: (BuildContext context, int index) {
return Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Container(
height: 70.0,
width: 148.0,
margin: EdgeInsets.only(top: 10.0),
decoration: BoxDecoration(
color: Colors.grey[800],
),
child: Row(
children: <Widget>[
Container(
width: 20.0,
decoration: BoxDecoration(color: Colors.grey[900]),
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
Container(
width: 7.0,
height: 7.0,
decoration:
BoxDecoration(color: Colors.white),
),
Container(
width: 7.0,
height: 7.0,
decoration:
BoxDecoration(color: Colors.white),
),
Container(
width: 7.0,
height: 7.0,
decoration:
BoxDecoration(color: Colors.white),
),
],
),
),
Expanded(
child: Container(
decoration: BoxDecoration(
color: Colors.black,
borderRadius: BorderRadius.circular(5.0),
),
margin:
new EdgeInsets.only(top: 1.0, bottom: 1.0),
child: selectedSegment[index] != null
? SizedBox(
height: double.infinity,
width: double.infinity,
child: Center(
child: Container(
decoration: BoxDecoration(
image: DecorationImage(
fit: BoxFit.fill,
image: NetworkImage(
selectedSegment[index]
['segmentUrl']),
),
),
)),
)
: Container(),
),
),
],
),
),
Container(
width: 148.0,
height: MediaQuery.of(context).size.height - 130.0,
child: ListView(
scrollDirection: Axis.vertical,
children: buildSegmentList(index),
),
),
],
);
},
),
),

Answer 1

Try this code i got bottom and up event state in listview..
class ScrollViewDemo extends StatelessWidget {
#override
Widget build(BuildContext context) {
// TODO: implement build
return MaterialApp(
home: ScrollViewTest(),
);
}
}
class ScrollViewTest extends StatefulWidget {
#override
State<StatefulWidget> createState() {
// TODO: implement createState
return ScrollViewState();
}
}
class ScrollViewState extends State<ScrollViewTest> {
ScrollController _controller;
String message = "";
_scrollListener() {
if (_controller.offset >= _controller.position.maxScrollExtent &&
!_controller.position.outOfRange) {
setState(() {
message = "reach the bottom";
});
}
if (_controller.offset <= _controller.position.minScrollExtent &&
!_controller.position.outOfRange) {
setState(() {
message = "reach the top";
});
}
}
#override
void initState() {
_controller = ScrollController();
_controller.addListener(_scrollListener);
super.initState();
}
#override
Widget build(BuildContext context) {
// TODO: implement build
return Scaffold(
appBar: AppBar(
title: Text("Scrollview Demo"),
),
body: Column(
children: <Widget>[
Container(
height: 50.0,
color: Colors.green,
child: Center(
child: Text(message),
),
),
Expanded(
child: ListView.builder(
controller: _controller,
itemCount: 30,
itemBuilder: (context, index) {
return ListTile(title: Text("Index : $index"));
},
),
),
],
),
);
}
}