默认情况下,在应用运行期间更改FAB时,“颤动中的脚手架”会为浮动操作按钮(FAB)设置动画。
如何禁用此动画?
documentation引用了FloatingActionButtonAnimator.scaling
动画,该动画会在按钮更改时缩放按钮:
/// Animator将[floatingActionButton]移动到新 [floatingActionButtonLocation]。 /// ///如果为null,则 [ScaffoldState]将使用默认的动画师, [FloatingActionButtonAnimator.scaling]。最后 FloatingActionButtonAnimator floatActionButtonAnimator;
但是,没有关于如何完全禁用缩放动画的指示。
有问题的完整示例代码:
import 'dart:async';
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key}) : super(key: key);
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
Timer _timer;
bool showFirst = true;
@override
void initState() {
_timer = Timer.periodic(new Duration(seconds: 2), (Timer t) {
setState(() {
showFirst = !showFirst;
});
});
super.initState();
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: Container(),
floatingActionButtonLocation: showFirst
? FloatingActionButtonLocation.centerDocked
: FloatingActionButtonLocation.endDocked,
floatingActionButton: Padding(
padding: EdgeInsets.only(top: 100.0),
child: Column(
children: <Widget>[
Text('Floating Action Button Title'),
showFirst
? FloatingActionButton.extended(
heroTag: 'unique',
icon: Icon(Icons.filter_1),
label: Text('First FAB'),
onPressed: () {},
)
: FloatingActionButton.extended(
heroTag: 'unique2',
icon: Icon(Icons.filter_2),
label: Text('Second FAB'),
onPressed: () {},
),
],
),
),
);
}
@override
void dispose() {
_timer.cancel();
super.dispose();
}
}
向每个FAB添加不同的英雄标签不会影响动画。
答案 0 :(得分:3)
您需要扩展FloatingActionButtonAnimator并覆盖其方法,检查以下代码,
import 'dart:async';
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: MyHomePage(),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key}) : super(key: key);
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
Timer _timer;
bool showFirst = true;
@override
void initState() {
_timer = Timer.periodic(new Duration(seconds: 2), (Timer t) {
setState(() {
showFirst = !showFirst;
});
});
super.initState();
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: Container(),
floatingActionButtonAnimator: NoScalingAnimation(),
floatingActionButtonLocation: showFirst
? FloatingActionButtonLocation.centerDocked
: FloatingActionButtonLocation.endDocked,
floatingActionButton: Padding(
padding: EdgeInsets.only(top: 100.0),
child: Column(
children: <Widget>[
Text('Floating Action Button Title'),
showFirst
? FloatingActionButton.extended(
heroTag: 'unique',
icon: Icon(Icons.filter_1),
label: Text('First FAB'),
onPressed: () {},
)
: FloatingActionButton.extended(
heroTag: 'unique2',
icon: Icon(Icons.filter_2),
label: Text('Second FAB'),
onPressed: () {},
),
],
),
),
);
}
@override
void dispose() {
_timer.cancel();
super.dispose();
}
}
class NoScalingAnimation extends FloatingActionButtonAnimator{
double _x;
double _y;
@override
Offset getOffset({Offset begin, Offset end, double progress}) {
_x = begin.dx +(end.dx - begin.dx)*progress ;
_y = begin.dy +(end.dy - begin.dy)*progress;
return Offset(_x,_y);
}
@override
Animation<double> getRotationAnimation({Animation<double> parent}) {
return Tween<double>(begin: 1.0, end: 1.0).animate(parent);
}
@override
Animation<double> getScaleAnimation({Animation<double> parent}) {
return Tween<double>(begin: 1.0, end: 1.0).animate(parent);
}
}
您可以通过更改每种方法返回的值来控制动画的行为。对于前。您可以通过将getOffset
方法更改为
@override
Offset getOffset({Offset begin, Offset end, double progress}) {
if (progress == 1.0){
return end;
}else{
return begin;
}
}
答案 1 :(得分:0)
floatingActionButtons具有名为heroTag的属性,每个floatActionButtons都具有相同的默认值。给每个floatActionButtons唯一的heroTag将阻止动画的发生。
eval