flultter listview异常type '(BuildContext, int) => dynamic' is not a subtype of type '
作者:互联网
type '(BuildContext, int) => dynamic' is not a subtype of type '(BuildContext, int) => Widget'
源码如下:
import 'package:flutter/material.dart'; import 'post.dart'; void main() { runApp(MaterialApp( title: 'Returning Data', home: HomePage(), )); } class HomePage extends StatelessWidget { @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: Text('Flutter SnackBar'), ), body: Center( child: new ListViewLayout(), )); } } class ListViewLayout extends StatelessWidget { _istviewItemBuilder(BuildContext context, int index) { return Text(posts[index].author); } @override Widget build(BuildContext context) { return ListView.builder( itemCount: posts.length, itemBuilder: _istviewItemBuilder); } }
原因是因为_istviewItemBuilder没写 返回值类型Widget 加上就可以
import 'package:flutter/material.dart'; import 'post.dart'; void main() { runApp(MaterialApp( title: 'Returning Data', home: HomePage(), )); } class HomePage extends StatelessWidget { @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: Text('Flutter SnackBar'), ), body: Center( child: new ListViewLayout(), )); } } class ListViewLayout extends StatelessWidget { Widget _istviewItemBuilder(BuildContext context, int index) { return Text(posts[index].author); } @override Widget build(BuildContext context) { return ListView.builder( itemCount: posts.length, itemBuilder: _istviewItemBuilder); } }
标签:Widget,return,int,istviewItemBuilder,BuildContext,context,type 来源: https://www.cnblogs.com/mingfeng002/p/11592774.html