如何在flutter中制作扩展的网格视图？

import 'package:flutter/material.dart';

class MyGridView extends StatefulWidget {
  @override
  _MyGridViewState createState() => _MyGridViewState();
}

class _MyGridViewState extends State<MyGridView> {
  List<String> items = [
    'Item 1',
    'Item 2',
    'Item 3',
    'Item 4',
    'Item 5',
    'Item 6',
    // 添加更多的项...
  ];

  @override
  Widget build(BuildContext context) {
    return GridView.builder(
      itemCount: items.length,
      gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
        crossAxisCount: 2, // 每行显示的列数
        mainAxisSpacing: 10.0, // 主轴方向的间距
        crossAxisSpacing: 10.0, // 交叉轴方向的间距
        childAspectRatio: 1.0, // 子组件宽高比
      ),
      itemBuilder: (context, index) {
        return Container(
          color: Colors.blue,
          child: Center(
            child: Text(
              items[index],
              style: TextStyle(
                color: Colors.white,
                fontSize: 20.0,
              ),
            ),
          ),
        );
      },
    );
  }
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('GridView Demo'),
        ),
        body: MyGridView(),
      ),
    );
  }
}