如何将 ListWheelScrollView 定位到给定的索引？

问题描述

我想将 ListWheelScrollView 定位到随机给定的索引。 在定位时，旋转动画也必须工作。 如何定位到给定的索引？

编辑：它就像老虎机一样。

解决方法

您可以在下面复制粘贴运行完整代码
您可以使用 FixedExtentScrollController 并调用 animateToItem
代码片段

final FixedExtentScrollController _controller = FixedExtentScrollController();
...
body: Center(
        child: ListWheelScrollView(
          controller: _controller,itemExtent: 80,magnification: 1.2,useMagnifier: true,physics: FixedExtentScrollPhysics(),children: listtiles,//List of widgets
        ),),floatingActionButton: FloatingActionButton(
        onPressed: () {
          _controller.animateToItem(random.nextInt(10),duration: Duration(milliseconds: 500),curve: Curves.linear);
        },child: Icon(Icons.add),backgroundColor: Colors.green,

工作演示

完整代码

import 'package:flutter/material.dart';
import 'dart:math';

void main() => 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: MyHomePage(),);
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final FixedExtentScrollController _controller = FixedExtentScrollController();
  Random random = Random();

  List<Widget> listtiles = [
    GestureDetector(
      onTap: () {
        print("clicked 1");
      },child: ListTile(
        leading: Icon(Icons.portrait),title: Text("Portrait"),subtitle: Text("Beautiful View..!"),trailing: Icon(Icons.arrow_forward_ios),GestureDetector(
      onTap: () {
        print("clicked 2");
      },child: ListTile(
        leading: Icon(Icons.landscape),title: Text("LandScape"),trailing: Icon(Icons.remove),GestureDetector(
      onTap: () {
        print("clicked 3");
      },child: ListTile(
        leading: Icon(Icons.map),title: Text("Map"),subtitle: Text("Map View..!"),trailing: Icon(Icons.wb_sunny),ListTile(
      leading: Icon(Icons.landscape),subtitle: Text("Wonderful View..!"),ListTile(
      leading: Icon(Icons.list),title: Text("List Example"),subtitle: Text("List Wheel Scroll view .!"),trailing: Icon(Icons.cloud),ListTile(
      leading: Icon(Icons.settings),title: Text("Settings"),subtitle: Text("Change the setting..!"),trailing: Icon(Icons.portrait),ListTile(
      leading: Icon(Icons.event),title: Text("Add data"),subtitle: Text("Data View..!"),trailing: Icon(Icons.add),ListTile(
      leading: Icon(Icons.email),title: Text("Email"),subtitle: Text("Check Email..!"),trailing: Icon(Icons.arrow_forward),ListTile(
      leading: Icon(Icons.games),title: Text("Games"),subtitle: Text("Play Games..!"),trailing: Icon(Icons.zoom_out_map),];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("ListView ScrollView Wheel"),body: Center(
        child: ListWheelScrollView(
          controller: _controller,);
  }
}