网格GridView：

count方法：

GridView.count(
              crossAxisCount: 2,//列数
              children: const [
                Icon(Icons.ac_unit),
                Icon(Icons.airport_shuttle),
                Icon(Icons.all_inclusive),
                Icon(Icons.beach_access),
                Icon(Icons.cake),
                Icon(Icons.free_breakfast)
              ],
            )

extend方法：

GridView.extent(
              maxCrossAxisExtent: 500,//行最大长度
              children: const [
                Icon(Icons.ac_unit),
                Icon(Icons.airport_shuttle),
                Icon(Icons.all_inclusive),
                Icon(Icons.beach_access),
                Icon(Icons.cake),
                Icon(Icons.free_breakfast),
                Icon(Icons.ac_unit),
                Icon(Icons.airport_shuttle),
                Icon(Icons.all_inclusive),
                Icon(Icons.beach_access),
                Icon(Icons.cake),
                Icon(Icons.free_breakfast),
              ],
            )

静态网格效果：

动态网格：builder，用法与ListView.builder基本相同

return GridView.builder(
      gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
        crossAxisCount: 2,
        crossAxisSpacing: 8.0,
        mainAxisSpacing: 8.0,
      ),
      itemCount: 20,
      itemBuilder: (context, index) {
        return Card(
          child: Center(
            child: Text('Grid Item $index'),
          ),
        );
      },
    );

同时学了一下Expanded()的使用，用于包裹Column/Row等的内部组件，适当的给子组件按比例分割，避免空间冲突导致报错，例如将屏幕分半，上半部分显示一个列表，下半部分显示一个网格：

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: MyScreen(),
    );
  }
}

class MyScreen extends StatelessWidget {
  const MyScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Split Screen Example'),
      ),
      body: const Column(
        children: [
          Expanded(
            child: MyListView(),
          ),
          Expanded(
            child: MyGridView(),
          ),
        ],
      ),
    );
  }
}

class MyListView extends StatelessWidget {
  const MyListView({super.key});

  @override
  Widget build(BuildContext context) {
    return ListView.builder(
      itemCount: 20,
      itemBuilder: (context, index) {
        return ListTile(
          title: Text('Item $index'),
        );
      },
    );
  }
}

class MyGridView extends StatelessWidget {
  const MyGridView({super.key});

  @override
  Widget build(BuildContext context) {
    return GridView.builder(
      gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
        crossAxisCount: 2,
        crossAxisSpacing: 8.0,
        mainAxisSpacing: 8.0,
      ),
      itemCount: 20,
      itemBuilder: (context, index) {
        return Card(
          child: Center(
            child: Text('Grid Item $index'),
          ),
        );
      },
    );
  }
}

效果：