如何使用flutter创建此效果。我使用了BackdropFilter，但我认为它不正确

import 'package:flutter/material.dart';

class MyBackdropFilter extends StatefulWidget {
  @override
  _MyBackdropFilterState createState() => _MyBackdropFilterState();
}

class _MyBackdropFilterState extends State<MyBackdropFilter> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        children: [
          // 背景图像
          Image.network(
            'https://example.com/background_image.jpg',
            fit: BoxFit.cover,
            width: double.infinity,
            height: double.infinity,
          ),
          // 使用BackdropFilter创建效果
          BackdropFilter(
            filter: ImageFilter.blur(sigmaX: 10, sigmaY: 10), // 设置模糊程度
            child: Container(
              color: Colors.black.withOpacity(0.5), // 设置背景颜色和透明度
            ),
          ),
          // 其他内容
          Center(
            child: Text(
              'Hello, World!',
              style: TextStyle(
                fontSize: 24,
                color: Colors.white,
              ),
            ),
          ),
        ],
      ),
    );
  }
}

void main() {
  runApp(MaterialApp(
    home: MyBackdropFilter(),
  ));
}