松约束

Column 宽度等于子元素最大宽度

import 'package:flutter/material.dart';

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

Widget build() {
  return MaterialApp(
    home: Scaffold(
      body: Column(
        children: const [
          Text("aaaaaaaaaaaaaaaaaaaaaa"),
          Text("aaaaaaaaaaa"),
        ],
      ),
    ),
  );
}

Container 紧包裹子元素

Scaffold 填充了整个屏幕，Container 包裹了 Column

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Container(
          color: Colors.amber,
          child: Column(
            children: const [
              Text("aaaaaaaaaaaaaaaa"),
              Text("bbbbbbbbb"),
            ],
          ),
        ),
      ),
    );
  }
}