如何在Flutter中将高度填充到父窗口(或获取父窗口大小)？

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('Flutter Parent Window Size'),
        ),
        body: Center(
          child: Container(
            color: Colors.blue,
            child: LayoutBuilder(
              builder: (BuildContext context, BoxConstraints constraints) {
                return Container(
                  height: constraints.maxHeight, // 将子窗口的高度填充到父窗口
                  width: constraints.maxWidth,
                  child: Center(
                    child: Text(
                      'Hello World',
                      style: TextStyle(
                        color: Colors.white,
                        fontSize: 24,
                      ),
                    ),
                  ),
                );
              },
            ),
          ),
        ),
      ),
    );
  }
}