How do I do the "frosted glass" effect in Flutter?

I'm writing a Flutter app, and I'd like to use/implement the "frosted glass" effect that's common on iOS. How do I do this?

You can use the BackdropFilter widget to achieve this effect.

import 'dart:ui';
import 'package:flutter/material.dart';

void main() {
  runApp(new MaterialApp(home: new FrostedDemo()));
}

class FrostedDemo extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        children: <Widget>[
          ConstrainedBox(
              constraints: const BoxConstraints.expand(),
              child: FlutterLogo()
          ),
          Center(
            child: ClipRect(
              child: BackdropFilter(
                filter: ImageFilter.blur(sigmaX: 10.0, sigmaY: 10.0),
                child: Container(
                  width: 200.0,
                  height: 200.0,
                  decoration: BoxDecoration(
                      color: Colors.grey.shade200.withOpacity(0.5)
                  ),
                  child: Center(
                    child: Text(
                        'Frosted',
                        style: Theme.of(context).textTheme.headlineLarge
                    ),
                  ),
                ),
              ),
            ),
          ),
        ],
      ),
    );
  }
}