如何在Flutter小部件中布局行和列

Row(
  children: [
    Expanded(
      child: Container(
        // 子小部件内容
      ),
    ),
    // 其他子小部件
  ],
)

Row(
  children: [
    Container(
      margin: EdgeInsets.only(right: 10),
      // 子小部件内容
    ),
    // 其他子小部件
  ],
)

Row(
  mainAxisAlignment: MainAxisAlignment.center,
  children: [
    // 子小部件
  ],
)

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Row and Column Example'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Row(
                mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                children: [
                  Text('Item 1'),
                  Text('Item 2'),
                  Text('Item 3'),
                ],
              ),
              Row(
                mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                children: [
                  Text('Item 4'),
                  Text('Item 5'),
                  Text('Item 6'),
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }
}