Flutter Layout Row / Column - 共享宽度，展开高度

Question

我在 Flutter 中的布局仍然有点问题。
现在我想在象限布局中的 3 个小部件之间共享可用的 space。宽度是均匀共享的（这可以通过连续 2 Expanded 个小部件正常工作），但现在我也希望高度自动调整，所以 widget3.height == widget1.height + widget2.height。如果widget3的内容比较大，我想让widget1和widget2调整高度，反之亦然。

这在 Flutter 中是否可行？

Answer 1

看看IntrinsicHeight；包装根行应该提供您正在寻找的效果：

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: Scaffold(
        appBar: AppBar(title: Text('Rows & Columns')),
        body: RowsAndColumns(),
      ),
    );
  }
}

class RowsAndColumns extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.only(top: 100.0),
      child: IntrinsicHeight(
        child: Row(crossAxisAlignment: CrossAxisAlignment.stretch, children: [
          Expanded(
            child: Column(children: [
              Container(height: 120.0, color: Colors.yellow),
              Container(height: 100.0, color: Colors.cyan),
            ]),
          ),
          Expanded(child: Container(color: Colors.amber)),
        ]),
      ),
    );
  }
}

调整列中容器的高度会导致右侧容器调整大小以匹配：

https://gist.github.com/mjohnsullivan/c5b661d7b3b4ca00599e8ef87ff6ac61

Answer 2

我是 Flutter 新手。如果我在这里做错了什么，请纠正我。我认为不使用 IntrinsicHeight 也可以使用 setState((){}) 来实现。

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}`enter code here`

class MyApp extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    return MyAppState();
  }
}

class MyAppState extends State<MyApp> {
  @override
  Widget build(BuildContext context) {
    double h1 = 100;
    double h2 = 200;
    double h3;
    setState(() {
      h3 = h1 + h2;
    });
    return MaterialApp(
      home: Scaffold(
        body: SafeArea(
          child: Padding(
            padding: const EdgeInsets.only(top: 100.0),
            child: Row(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Expanded(
                  child: Column(
                    children: [
                      Container(
                        color: Colors.green,
                        height: h1,
                      ),
                      Container(
                        color: Colors.orange,
                        height: h2,
                      )
                    ],
                  ),
                ),
                Expanded(
                  child: Container(
                    color: Colors.yellow,
                    height: h3,
                  ),
                )
              ],
            ),
          ),
        ),
      ),
    );
  }
}

Find image here

代码也可以在这里找到：https://gist.github.com/Amrit0786/9d228017c2df6cf277fbbaa4a6b20e83

Answer 3

我认为你可以设置行的高度，然后你只需要设置列容器的高度，并使用 crossAxisAlignment: CrossAxisAlignment.stretch 第二行会展开占据他父级的高度：

SizedBox(
 height: 100,
 child: Row(
 crossAxisAlignment: CrossAxisAlignment.stretch,
 children: [
  Expanded(
    child: Column(
      children: [
        Expanded( //If you dont have the height you can expanded with flex
          flex: 1,
          child: Container(
            height: 50,
            color: Colors.blue,
          ),
        ),
        Expanded(
          flex: 1,
          child: Container(
            height: 50,
            color: Colors.red,
          ),
        )
      ],
    ),
  ),
  Expanded(
    child: Container(
      color: Colors.yellow,
    ),
   )
  ],
 ),
),

Answer 4

既然IntrinsicHeight被认为是relatively expensive，最好还是避免。您可以使用 Table with verticalAlignment: TableCellVerticalAlignment.fill 在最大的 TableCell.

请注意，如果您在所有单元格中使用 .fill，则 TableRow 将具有 zero height。

  Table(children: [
    TableRow(children: [
      Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Container(
            alignment: Alignment.center,
            color: Colors.blue,
            child: Text('Widget 1'),
          ),
          Container(
            alignment: Alignment.center,
            color: Colors.green,
            child: Text('Widget 2'),
          ),
        ],
      ),
      TableCell(
          verticalAlignment: TableCellVerticalAlignment.fill,
          child: Container(
            alignment: Alignment.center,
            color: Colors.orange,
            child: Text('Widget 3'),
          )),
    ]),
  ]),

Flutter Layout Row / Column - 共享宽度，展开高度

Flutter Layout Row / Column - share width, expand height

flutter

flutter-layout