Ios 如何滚动cupertino选择器自动抖动?
我正在为IOS开发一款新的Flitter应用程序。我也在使用Cupertino选择器,我想自动滚动选择器,而不需要用户的任何触摸 我能做到这一点吗Ios 如何滚动cupertino选择器自动抖动?,ios,flutter,dart,scroll,picker,Ios,Flutter,Dart,Scroll,Picker,我正在为IOS开发一款新的Flitter应用程序。我也在使用Cupertino选择器,我想自动滚动选择器,而不需要用户的任何触摸 我能做到这一点吗 谢谢。您可以复制粘贴运行下面的完整代码 您可以使用scrollController 代码片段 scrollController.animateTo(itemExtent, duration: Duration(milliseconds: 200), curve: Curves.ease); CupertinoPicker(
谢谢。您可以复制粘贴运行下面的完整代码
您可以使用
scrollController
代码片段
scrollController.animateTo(itemExtent,
duration: Duration(milliseconds: 200), curve: Curves.ease);
CupertinoPicker(
scrollController: scrollController,
itemExtent: itemExtent,
工作演示
完整代码
import 'package:flutter/material.dart';
import 'package:flutter/cupertino.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class BuildingProblem {
static List<Icon> problemListIcons = [];
static List<String> problemListNames = [];
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
int _selectedColorIndex = 0;
double itemExtent = 40.0;
FixedExtentScrollController scrollController;
void _incrementCounter() {
scrollController.animateTo(itemExtent,
duration: Duration(milliseconds: 200), curve: Curves.ease);
setState(() {
_counter++;
});
}
@override
void initState() {
scrollController =
FixedExtentScrollController(initialItem: _selectedColorIndex);
BuildingProblem.problemListIcons.add(Icon(Icons.add));
BuildingProblem.problemListIcons.add(Icon(Icons.cast));
BuildingProblem.problemListIcons.add(Icon(Icons.link));
BuildingProblem.problemListNames.add("add");
BuildingProblem.problemListNames.add("cast");
BuildingProblem.problemListNames.add("link");
// TODO: implement initState
super.initState();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Expanded(
child: CupertinoPicker(
scrollController: scrollController,
itemExtent: itemExtent,
children: <Widget>[
for (var i = 0;
i < BuildingProblem.problemListIcons.length;
i++)
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
BuildingProblem.problemListIcons[i],
Padding(
padding: EdgeInsets.only(left: 10),
child: Text(
BuildingProblem.problemListNames[i],
style: TextStyle(color: Colors.white70),
),
)
],
),
],
onSelectedItemChanged: (int index) {
print('good boi');
},
looping: true,
backgroundColor: Color(0xff2e3032),
),
),
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.display1,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
导入“包装:颤振/材料.省道”;
进口“包装:颤振/cupertino.dart”;
void main()=>runApp(MyApp());
类MyApp扩展了无状态小部件{
@凌驾
小部件构建(构建上下文){
返回材料PP(
标题:“颤振演示”,
主题:主题数据(
主样本:颜色。蓝色,
),
主页:MyHomePage(标题:“颤振演示主页”),
);
}
}
类构建问题{
静态列表问题ListIcons=[];
静态列表问题ListNames=[];
}
类MyHomePage扩展StatefulWidget{
MyHomePage({Key,this.title}):超级(Key:Key);
最后的字符串标题;
@凌驾
_MyHomePageState createState()=>\u MyHomePageState();
}
类_MyHomePageState扩展状态{
int _计数器=0;
int _selectedColorIndex=0;
双项目范围=40.0;
FixedExtentScrollController scrollController;
void _incrementCounter(){
scrollController.animateTo(itemExtent,
持续时间:持续时间(毫秒:200),曲线:Curves.ease);
设置状态(){
_计数器++;
});
}
@凌驾
void initState(){
滚动控制器=
FixedExtentScrollController(初始项:\ u selectedColorIndex);
BuildingProblem.problemListIcons.add(Icon(Icons.add));
BuildingProblem.problemListIcons.add(Icon(Icons.cast));
BuildingProblem.problemListIcons.add(Icon(Icons.link));
BuildingProblem.problemListNames.add(“add”);
BuildingProblem.problemListNames.add(“cast”);
BuildingProblem.problemListNames.add(“链接”);
//TODO:实现initState
super.initState();
}
@凌驾
小部件构建(构建上下文){
返回脚手架(
appBar:appBar(
标题:文本(widget.title),
),
正文:中(
子:列(
mainAxisAlignment:mainAxisAlignment.center,
儿童:[
扩大(
孩子:CupertinoPicker(
scrollController:scrollController,
itemExtent:itemExtent,
儿童:[
对于(var i=0;
i
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