Flutter ScrollController不能正常工作
Flutter ScrollController不能正常工作
提问于 2021-06-04 22:09:46
在我的flutter应用程序中，我尝试使用scrollController在listBuilder中滚动列表视图，但ScrollController无法正常工作。它不会显示错误或异常，但列表不会滚动。即使我使用滚动控制器jumpTo或animateTo，它也不能工作。即使我给出了最大值，比如animateTo和jumpTo中的20000和1000，它也不会滚动。
import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';
class Class extends StatefulWidget {
final int data;
final List list;
Class({required this.data, required this.list});
@override
_ClassState createState() => _ClassState();
}
class _ClassState extends State<Class> with TickerProviderStateMixin {
late Animation<double> animation;
late AnimationController animationController;
late double height = 0;
final List lst = [
[true, true, true, true],
[false, false, false, false],
[true, false, false, false],
[true, false, false, false],
[true, false, false, false],
[false, false, false, false],
[true, false, false, false],
[false, false, false, false],
[true, false, false, false],
[false, false, false, false],
[true, false, false, false],
[false, false, false, false],
[true, false, false, false],
[false, false, false, false],
[true, false, false, false],
];
void initState() {
super.initState();
animationController =
AnimationController(vsync: this, duration: Duration(seconds: 5));
animation = Tween<double>(begin: 0, end: 200).animate(animationController)
..addListener(() {
setState(() {});
})
..addStatusListener((status) {});
animationController.forward();
}
Widget container(data) {
return Stack(
children: [
GestureDetector(
onTap: () {
setState(() {
animationController.forward();
});
},
child: Transform.translate(
offset: Offset(0, animation.value),
child: Container(
color: lst[data][0] ? Colors.black : Colors.transparent,
height: MediaQuery.of(context).size.height / 4,
width: MediaQuery.of(context).size.width / 4,
child: Text('$data'),
),
),
),
],
);
}
@override
Widget build(BuildContext context) {
return container(widget.data);
}
@override
void dispose() {
super.dispose();
animationController.dispose();
}
}
class Yes extends StatefulWidget {
@override
_YesState createState() => _YesState();
}
class _YesState extends State<Yes> {
List lst = [
[true, true, true, true],
[false, false, false, false],
[true, false, false, false],
[true, false, false, false],
[true, false, false, false],
[false, false, false, false],
[true, false, false, false],
[false, false, false, false],
[true, false, false, false],
[false, false, false, false],
[true, false, false, false],
[false, false, false, false],
[true, false, false, false],
[false, false, false, false],
[true, false, false, false],
];
ScrollController _scrollController = ScrollController();
void initState() {
if (_scrollController.hasClients) {
super.initState();
// _scrollController.animateTo(0,
// // _scrollController.offset + MediaQuery.of(context).size.height/6,
// duration: Duration(seconds: 2),
// curve: Curves.linear);
_scrollController.jumpTo(_scrollController.position.maxScrollExtent);
}
}
@override
Widget build(BuildContext context) {
return ListView(
controller: _scrollController,
// physics: NeverScrollableScrollPhysics(),
children: [
ListView.builder(
// physics: NeverScrollableScrollPhysics(),
reverse: true,
itemCount: lst.length,
controller: _scrollController,
itemBuilder: (BuildContext context, int position) {
return Stack(children: [Class(data: position, list: lst)]);
}),
],
);
}
}Stack Overflow用户
发布于 2021-06-05 02:27:35
您的代码不够清楚，但作为示例尝试一下，效果很好
runApp(MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: ListExample(),
);
}
}
class ListExample extends StatelessWidget {
ListExample({Key? key}) : super(key: key);
final ScrollController controller = ScrollController();
double pos = 0;
@override
Widget build(BuildContext context) {
return Scaffold(
body: Column(
children: [
Expanded(
child: ListView.builder(
controller: controller,
itemCount: 10000,
itemBuilder: (context, index) {
return Text('item $index');
},
),
),
ElevatedButton(
onPressed: () {
controller.jumpTo(pos+=250);
},
child: Text(' Jump'))
],
),
);
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/67838717
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