如何在扑动中做“磨砂玻璃”效果？

您可以使用 BackdroFilter 小部件来达到这个效果。

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 new Scaffold(
body: new Stack(
children: <Widget>[
new ConstrainedBox(
constraints: const BoxConstraints.expand(),
child: new FlutterLogo()
),
new Center(
child: new ClipRect(
child: new BackdropFilter(
filter: new ImageFilter.blur(sigmaX: 10.0, sigmaY: 10.0),
child: new Container(
width: 200.0,
height: 200.0,
decoration: new BoxDecoration(
color: Colors.grey.shade200.withOpacity(0.5)
),
child: new Center(
child: new Text(
'Frosted',
style: Theme.of(context).textTheme.display3
),
),
),
),
),
),
],
),
);
}
}

我想我不知道“霜冻”的确切含义(如果我的例子在这里不起作用) ,

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


void main() => runApp(
MaterialApp(
title: "Frosted glass",
home: new HomePage()
)
);


class HomePage extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new Scaffold(
body: new Stack(
fit: StackFit.expand,
children: <Widget>[
generateBluredImage(),
new Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
rectShapeContainer(),
],
),
],
),
);
}


Widget generateBluredImage() {
return new Container(
decoration: new BoxDecoration(
image: new DecorationImage(
image: new AssetImage('assets/images/huxley-lsd.png'),
fit: BoxFit.cover,
),
),
//I blured the parent container to blur background image, you can get rid of this part
child: new BackdropFilter(
filter: new ui.ImageFilter.blur(sigmaX: 3.0, sigmaY: 3.0),
child: new Container(
//you can change opacity with color here(I used black) for background.
decoration: new BoxDecoration(color: Colors.black.withOpacity(0.2)),
),
),
);
}


Widget rectShapeContainer() {
return Container(
margin: const EdgeInsets.symmetric(horizontal: 40.0, vertical: 10.0),
padding: const EdgeInsets.all(15.0),
decoration: new BoxDecoration(
//you can get rid of below line also
borderRadius: new BorderRadius.circular(10.0),
//below line is for rectangular shape
shape: BoxShape.rectangle,
//you can change opacity with color here(I used black) for rect
color: Colors.black.withOpacity(0.5),
//I added some shadow, but you can remove boxShadow also.
boxShadow: <BoxShadow>[
new BoxShadow(
color: Colors.black26,
blurRadius: 5.0,
offset: new Offset(5.0, 5.0),
),
],
),
child: new Column(
children: <Widget>[
new Text(
'There\'s only one corner of the universe you can be certain of improving and that\'s your own self.',
style: new TextStyle(
color: Colors.white,
fontSize: 20.0,
),
),
],
),
);
}
}

结果:

我希望这能帮到别人。

BackdropFilter(
filter: ImageFilter.blur(sigmaX: _sigmaX, sigmaY: _sigmaY),
child: Container(
color: Colors.black.withOpacity(_opacity),
),
),