[英]Flutter: Using an array of Stateful Widgets inside a Stateful Widget causes a 'A RenderFlex overflow'
我正在學習Flutter,我在構建一個簡單的應用程序時遇到了這種奇怪的行為。 我已經創建了一個自定義狀態窗口小部件,我根本無法在另一個狀態窗口小部件中使用它。 這是預期的行為還是我在這里遺漏了什么?
錯誤是:
引發了以下NoSuchMethodError構建MediaQuery(MediaQueryData(size:Size(375.0,812.0),devicePixelRatio:3.0,textScaleFactor:1.0,padding:EdgeInsets(0.0,0.0,0.0,34.0),viewInsets:EdgeInsets.zero,alwaysUse24HourFormat:false) ):方法'_debugTypesAreRight'在null上調用。 Receiver:null嘗試調用:_debugTypesAreRight('TextCard'的實例)
和
拋出了另一個異常:_ScaffoldLayout自定義多層布局委托忘記布置以下子節點:
編碼:
import 'package:flutter/material.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Stateful Widget 02',
theme: new ThemeData(
primarySwatch: Colors.blue,
),
home: new MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key}) : super(key: key);
@override
_MyHomePageState createState() => new _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
@override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text('Testing nested Stateful Widgets'),
),
body: new Center(
child: new Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
new TextCard(),
new TextCard()
],
),
),
);
}
}
class TextCard extends StatefulWidget {
@override
State<StatefulWidget> createState() {
_TextCardState createState() => new _TextCardState();
}
}
class _TextCardState extends State<TextCard> {
@override
Widget build(BuildContext context) {
return new Card(
child: new Text('12312')
);
}
}
您正在以錯誤的方式覆蓋TextCard
的createState()
。
更換:
createState() {
_TextCardState createState() => new _TextCardState();
}
附:
@override
_TextCardState createState(){
return new _TextCardState();
}
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.