儿童身高的容器

Question

我有一列，其中有多个容器作为子容器，我希望容器的高度为子容器的高度。正在这样做：

SingleChildScrollView(
                      child: Column(
                      crossAxisAlignment: CrossAxisAlignment.stretch,
                      children: <Widget>[
                        Text(''),
                        Container(
                          child: WebView(
                              initialUrl:'',
                              javascriptMode: JavascriptMode.unrestricted),
                        ),
                        Text(''),
                        Container(
                          child: WebView(
                              initialUrl:'',
                              javascriptMode: JavascriptMode.unrestricted),
                        ),
                        Text(''),
                        Container(
                          child: WebView(
                              initialUrl:'',
                              javascriptMode: JavascriptMode.unrestricted),
                        ),

                      ],
                    ))

但这会返回此错误：

  

所有FlutterError对象应仅包含一个简短（一行）的摘要来描述所检测到的问题。   格式错误的错误     在布局过程中，为RenderSemanticsGestureHandler对象赋予了无限大小。

     

这可能意味着它是一个试图尽可能大的渲染对象，但是它被放置在另一个渲染对象中，允许其子代选择自己的大小。

如果我将高度添加到容器中，它将可以正常工作，但是我不想添加高度，我希望它采用其高度。

如何解决此问题？

Answer 1

条件1：删除SingleChildScrollView并使用Expanded flex占据手机的全屏高度，请参见完整代码1

条件2：使用SingleChildScrollView和“包装”将容器设置为高高度（例如2000），并采用相关高度和可滚动方式，请参见完整代码2

SingleChildScrollView(
        child: Container(
          height: 2000,
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: <Widget>[
              Text(''),
              Expanded(
                flex: 1,
                child: Container(
                  child: WebView(
                      initialUrl: 'https://www.google.com',
                      javascriptMode: JavascriptMode.unrestricted),
                ),
              ),

条件1的完整代码1

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

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(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: <Widget>[
          Text(''),
          Expanded(
            flex: 1,
            child: Container(
              child: WebView(
                  initialUrl: 'https://www.google.com',
                  javascriptMode: JavascriptMode.unrestricted),
            ),
          ),
          Text(''),
          Expanded(
              flex: 1,
              child: Container(
                child: WebView(
                    initialUrl: 'https://www.google.com',
                    javascriptMode: JavascriptMode.unrestricted),
              )),
          Text(''),
          Expanded(
            flex: 1,
            child: Container(
              child: WebView(
                  initialUrl: 'https://www.google.com',
                  javascriptMode: JavascriptMode.unrestricted),
            ),
          ),
        ],
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

条件2完整代码2

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

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(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: SingleChildScrollView(
        child: Container(
          height: 2000,
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: <Widget>[
              Text(''),
              Expanded(
                flex: 1,
                child: Container(
                  child: WebView(
                      initialUrl: 'https://www.google.com',
                      javascriptMode: JavascriptMode.unrestricted),
                ),
              ),
              Text(''),
              Expanded(
                  flex: 1,
                  child: Container(
                    child: WebView(
                        initialUrl: 'https://www.google.com',
                        javascriptMode: JavascriptMode.unrestricted),
                  )),
              Text(''),
              Expanded(
                flex: 1,
                child: Container(
                  child: WebView(
                      initialUrl: 'https://www.google.com',
                      javascriptMode: JavascriptMode.unrestricted),
                ),
              ),
            ],
          ),
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}