Whenever I scroll in my listview, I get this error spammed in console:
ScrollController not attached to any scroll views.
'package:flutter/src/widgets/scroll_controller.dart':
Failed assertion: line 110 pos 12: '_positions.isNotEmpty'
I've been trying to fix this all day and I'd like to have someone else take a look at it. There are more problems with this code, but right now I'm mainly interested in fixing this error.
I've tried to use Listview.builder, checking for hController.hasClients and many more small things. They didn't seem to change anything
class MyHome extends StatefulWidget {
@override
MyHomeState createState() => new MyHomeState();
}
class MyHomeState extends State<MyHome> with SingleTickerProviderStateMixin {
ScrollController hController;
ScrollController tController;
ScrollController fController;
ScrollController bController;
@override
void initState() {
super.initState();
hController = new ScrollController()..addListener(_scrollListener);
tController = new ScrollController()..addListener(_scrollListener);
fController = new ScrollController()..addListener(_scrollListener);
bController = new ScrollController()..addListener(_scrollListener);
}
@override
void dispose() {
super.dispose();
hController.removeListener(_scrollListener);
tController.removeListener(_scrollListener);
fController.removeListener(_scrollListener);
bController.removeListener(_scrollListener);
}
@override
Widget build(BuildContext context) {
return new DefaultTabController(
length: 4,
child: new Scaffold(
//Removed AppBar for readability
body: new TabBarView(
children: [
new Container(// hot
child: ListView(
controller: hController,
children: <Widget>[
Utils.show("hot")
],
),
),
new Container( //Trending
child: ListView(
controller: tController,
children: <Widget>[
Utils.show("trending")
],
),
),
new Container( //Fresh
child: ListView(
controller: fController,
children: <Widget>[
Utils.show("fresh")
],
),
),
new Container( //Best
child: ListView(
controller: bController,
children: <Widget>[
Utils.show("best")
],
),
),
],
),
));
}
void _scrollListener() {
if (hController.position.extentAfter == 0.0) {
setState(() {
Utils.show("hot");
});
}else if (tController.position.extentAfter == 0.0) {
setState(() {
Utils.show("trending");
});
} else if (fController.position.extentAfter == 0.0) {
setState(() {
Utils.show("fresh");
});
} else if (bController.position.extentAfter == 0.0) {
setState(() {
Utils.show("best");
});
}
}
}
Edit: For some clarity, the first time I posted this code, I used tController twice. This was ofcourse a mistake, but did not solve the error. The error happens when scrolling in every one of the four listviews.
By default, scrollable widgets in Flutter don't show a scrollbar. To add a scrollbar to a ScrollView, wrap the scroll view widget in a Scrollbar widget. Using this widget we can scroll a widget. The scrollbar allows the user to jump into the particular points and also shows how far the user reaches.
forward, then scroll offset is the amount the top of the sliver has been scrolled past the top of the viewport.
A box in which a single widget can be scrolled. This widget is useful when you have a single box that will normally be entirely visible, for example a clock face in a time picker, but you need to make sure it can be scrolled if the container gets too small in one axis (the scroll direction).
To avoid such type of errors use the getter
ScrollController.hasClient
If this is false, then members that interact with the [ScrollPosition],such as [position], [offset], [animateTo], and [jumpTo], must not be called.
for example:
if (_controller.hasClients) {
_controller.animateTo(
...
}
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