将项目添加到列表时如何刷新我的 ListView.builder?

ListView.builder(
      itemCount: propList.length,
      scrollDirection: Axis.horizontal,
      shrinkWrap: true,
      itemBuilder: (context,index)=> Text(propList[index]),
    )

我的按钮是
FlatButton(onPressed: (){propList.add('text');}, child: Text('add'))

最佳答案

假设您已经扩展了 StatefulWidget ,则每次更改状态时都必须调用 setState 。前任:

setState(() { propList.add('text'); });

这是一个快速示例:

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) => MaterialApp(home: MyList());
}

class MyList extends StatefulWidget {
  @override
  _MyListState createState() => _MyListState();
}

class _MyListState extends State<MyList> {
  List<String> propList = [];
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('My List'),
      ),
      body: ListView.builder(
        itemCount: propList.length,
        scrollDirection: Axis.horizontal,
        shrinkWrap: true,
        itemBuilder: (context,index)=> Text(propList[index]),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () => setState(() => propList.add('text')),
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

关于list - 如何刷新 ListView.builder flutter ,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/59927528/

10-09 23:01