要让AnimatedSwitcher不执行动画,可以通过设置transitionBuilder属性来实现。下面是一个示例代码:
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('AnimatedSwitcher Example'),
),
body: MyWidget(),
),
);
}
}
class MyWidget extends StatefulWidget {
@override
_MyWidgetState createState() => _MyWidgetState();
}
class _MyWidgetState extends State {
int _count = 0;
@override
Widget build(BuildContext context) {
return Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
AnimatedSwitcher(
duration: Duration(milliseconds: 500),
transitionBuilder: (Widget child, Animation animation) {
// 不执行动画
return child;
},
child: Text(
'Count: $_count',
key: ValueKey(_count),
style: TextStyle(fontSize: 24),
),
),
SizedBox(height: 20),
RaisedButton(
child: Text('Increment'),
onPressed: () {
setState(() {
_count++;
});
},
),
],
);
}
}
在上面的例子中,我们通过设置transitionBuilder属性为一个函数,该函数接收一个child和animation参数,然后直接返回child。这样就可以让AnimatedSwitcher不执行任何动画。