我已经将ScrollController附加到[SliverAppBar,SliverList]的CustomScrollView
在默认情况下,我会使用reverse：true和animateTo(0.0)将滚动移动到添加的最后一个元素,但在这种情况下使用reverse也会反转SliverAppBar / SliverList顺序！
所以我想使用animateTo(sizeOfScrollableAfterElementAdded)但我找不到这个值.
谢谢 ！
解决方法
您可以使用_scrollController.position.maxScrollExtent滚动到结尾.确保在后框架回调中执行此操作,以便它包含刚刚添加的新项目.
以下是添加更多项目时滚动到最后的条子列表的示例.
import 'package:flutter/scheduler.dart';
import 'package:flutter/material.dart';
void main() {
runApp(new MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Flutter Demo',home: new MyHomePage(),);
}
}
class MyHomePage extends StatefulWidget {
State createState() => new MyHomePageState();
}
class MyHomePageState extends State<MyHomePage> {
ScrollController _scrollController = new ScrollController();
List<Widget> _items = new List.generate(40,(index) {
return new Text("item $index");
});
@override
Widget build(BuildContext context) {
return new Scaffold(
floatingActionButton: new FloatingActionButton(
child: new Icon(Icons.arrow_downward),onPressed: () {
setState(() {
_items.add(new Text("item ${_items.length}"));
});
SchedulerBinding.instance.addPostFrameCallback((_) {
_scrollController.animateTo(
_scrollController.position.maxScrollExtent,duration: const Duration(milliseconds: 300),curve: Curves.eaSEOut,);
});
},),body: new CustomScrollView(
controller: _scrollController,slivers: [
new SliverAppBar(
title: new Text('Sliver App Bar'),new SliverList(
delegate: new SliverChildBuilderDelegate(
(context,index) => _items[index],childCount: _items.length,],);
}
}
