在 Flutter 中将新的 ListTile 作为子项添加后，ListView 更新不会更新

Question

我有一个简单的 flutter 应用程序，它只显示 ListView 的 ListTiles...此 listView 的子项属性设置为名为“tiles”的列表...每当用户按下浮动操作按钮，然后将一个新的 ListTiles 对象添加到“tiles”，并将其包装在设置状态中... 所以我希望 UI 更新并向我显示新的更新列表视图更多 ListTiles...但这并没有发生...

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Home(),
    );
  }
}

class Home extends StatefulWidget {
  @override
  _HomeState createState() => _HomeState();
}

class _HomeState extends State<Home> {
  List<ListTile> tiles = [];

  @override
  Widget build(BuildContext context) {
    print('length of tiles: ${tiles.length}');  // prints the length of tiles correctly
    return Scaffold(
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          setState(() {
            tiles.add(ListTile(title: Text('Hello ${tiles.length+1}')));
          });
        },
      ),
      body: ListView(children: tiles),
    );
  }
}

Answer 1

正如@LonelyWolf 所说：您应该使用 ListView.builder 并将字符串添加到您的列表而不是小部件

class Home extends StatefulWidget {
  @override
  _HomeState createState() => _HomeState();
}

class _HomeState extends State<Home> {
  List<String> tiles = [];

  @override
  Widget build(BuildContext context) {
    print('length of tiles: ${tiles.length}');  // prints the length of tiles correctly
    return Scaffold(
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          setState(() {
            tiles.add("${tiles.length+1}");
          });
        },
      ),
      body: ListView.builder(
        itemCount: tiles.length,
        itemBuilder: (_, index){
          return ListTile(
            title: Text('Hello ${tiles[index]}'),
          );
        },
      ),
    );
  }
}

在 Flutter 中将新的 ListTile 作为子项添加后，ListView 更新不会更新

ListView update doesn't update after new ListTile gets added as a children in Flutter

flutter

flutter-listview