Flutter 小部件在行中的动态高度

Question

如何将小部件的高度动态扩展到父小部件。

特别是在我的示例中，我想将红色条扩展到父小部件。 我的文本可以更改为 x 行。

当前代码：

import 'package:flutter/material.dart';

class ExampleView extends StatelessWidget {
  final String title;

  const ExampleView({Key key, this.onTap, this.title}) : super(key: key);

  final text = 'Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et';

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: EdgeInsets.only(left: 40),
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      color: Colors.grey[200],
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: <Widget>[
          Container(
            margin: const EdgeInsets.only(right: 12, top: 4, bottom: 4),
            width: 6,
            height: 80, // FIXME: Dynamic
            color: Colors.red,
          ),
          Expanded(
            child: Text(text),
          )
        ],
      ),
    );
  }
}

当前解决方案：

所需的解决方案：

预先感谢您的帮助！

Answer 1

您可以在下面复制粘贴运行完整代码
您可以使用IntrinsicHeight
代码片段

IntrinsicHeight(
        child: Row(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: <Widget>[
            Container(
              margin: const EdgeInsets.only(right: 12, top: 4, bottom: 4),
              width: 6,
              color: Colors.red,
            ),

工作演示

完整代码

import 'package:flutter/material.dart';

class ExampleView extends StatelessWidget {
  final String title;

  const ExampleView({Key key, this.title}) : super(key: key);

  final text = 'Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et';

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: EdgeInsets.only(left: 40),
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      color: Colors.grey[200],
      child: IntrinsicHeight(
        child: Row(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: <Widget>[
            Container(
              margin: const EdgeInsets.only(right: 12, top: 4, bottom: 4),
              width: 6,
              color: Colors.red,
            ),
            Expanded(
              child: Text(text),
            )
          ],
        ),
      ),
    );
  }
}

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

class MyApp extends StatelessWidget {  
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(       
        primarySwatch: Colors.blue,       
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

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

  final String title;

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

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

  void _incrementCounter() {
    setState(() {     
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {    
    return Scaffold(
      appBar: AppBar(       
        title: Text(widget.title),
      ),
      body: Center(        
        child: Column(          
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            ExampleView(),
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }
}

Answer 2

解决方案#1

在这种特殊情况下，您不需要使用 Row 小部件。 您可以将红色列添加为边框而不是容器小部件。 代码将如下所示：

class ExampleView extends StatelessWidget {
  final String title;

  const ExampleView({Key key, this.title}) : super(key: key);

  final text =
      'Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et';

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: EdgeInsets.only(left: 40),
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      color: Colors.grey[200],
      child: Container(
        decoration: BoxDecoration(
            border: Border(left: BorderSide(width: 6, color: Colors.red))),
        margin: const EdgeInsets.only(right: 12, top: 4, bottom: 4),
        padding: const EdgeInsets.only(left: 8),
        child: Text(text),
      ),
    );
  }
}

解决方案#2

代替边框，您可以翻译您的子 Container 并用另一个具有渐变的 Container 包裹它。

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: EdgeInsets.only(left: 40),
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      color: Colors.grey[200],
      child: Container(
        margin: const EdgeInsets.only(right: 12, top: 4, bottom: 4),
        decoration: BoxDecoration(
            gradient: LinearGradient(
          begin: Alignment.topCenter,
          end: Alignment.bottomCenter,
          colors: [
            Color.fromRGBO(255, 25, 25, 1),
            Color.fromRGBO(180, 21, 236, 1)
          ],
        )),
        child: Container(
          color: Colors.grey[200],
          transform: Matrix4.translationValues(6, 0, 0),
          padding: const EdgeInsets.only(left: 8),
          child: Text(text),
        ),
      ),
    );
  }