Function 如何在颤振中创建循环函数
我想让一个小部件(风扇)旋转直到用户点击它。 为此,我想我要用一个函数,但问题是 当bool=false时,如何生成停止的循环函数 这是我当前的函数(不循环): 和手势检测器功能:Function 如何在颤振中创建循环函数,function,loops,flutter,Function,Loops,Flutter,我想让一个小部件(风扇)旋转直到用户点击它。 为此,我想我要用一个函数,但问题是 当bool=false时,如何生成停止的循环函数 这是我当前的函数(不循环): 和手势检测器功能: void fanRotation() { if(angleController.status == AnimationStatus.completed){ angleController.stop(); fanState = false; } else if (
void fanRotation() {
if(angleController.status == AnimationStatus.completed){
angleController.stop();
fanState = false;
} else if (angleController.status == AnimationStatus.dismissed) {
angleController.forward();
fanState = true;
}
}
}
我希望它有一个连续的循环,这样就不会停止和再次启动。您需要一个
计时器。周期性的:
使用它来保持旋转功能的运行,并在单击时将其关闭
var timer = Timer.periodic(Duration(seconds: 5), (timer) {
//Your function goes here
});
// Cancel the timer
timer.cancel();
您可以复制粘贴运行下面的完整代码
您可以在initState()
中直接调用angleController.repeat()
,并在单击fan
时调用angleController.stop()
代码片段
@override
void initState() {
super.initState();
angleController =
AnimationController(vsync: this, duration: Duration(seconds: 3));
angleController.repeat();
}
...
GestureDetector(
onTap: () {
angleController.stop();
},
child: Icon(
Icons.forward,
color: Colors.pink,
size: 100.0,
)),
工作演示
完整代码
import 'package:flutter/material.dart';
import 'dart:math';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage>
with SingleTickerProviderStateMixin {
AnimationController angleController;
@override
void initState() {
super.initState();
angleController =
AnimationController(vsync: this, duration: Duration(seconds: 3));
angleController.repeat();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
AnimatedBuilder(
animation: angleController,
builder: (_, child) {
return Transform.rotate(
angle: angleController.value * pi * 2,
child: child,
);
},
child: GestureDetector(
onTap: () {
angleController.stop();
},
child: Icon(
Icons.forward,
color: Colors.pink,
size: 100.0,
)),
),
],
),
),
);
}
}
导入“包装:颤振/材料.省道”;
导入“dart:math”;
void main(){
runApp(MyApp());
}
类MyApp扩展了无状态小部件{
@凌驾
小部件构建(构建上下文){
返回材料PP(
标题:“颤振演示”,
主题:主题数据(
主样本:颜色。蓝色,
视觉密度:视觉密度。自适应平台密度,
),
主页:MyHomePage(标题:“颤振演示主页”),
);
}
}
类MyHomePage扩展StatefulWidget{
MyHomePage({Key,this.title}):超级(Key:Key);
最后的字符串标题;
@凌驾
_MyHomePageState createState()=>\u MyHomePageState();
}
类_MyHomePageState扩展状态
使用SingleTickerProviderStateMixin{
动画控制器;
@凌驾
void initState(){
super.initState();
角度控制器=
AnimationController(vsync:this,duration:duration(秒数:3));
重复();
}
@凌驾
小部件构建(构建上下文){
返回脚手架(
appBar:appBar(
标题:文本(widget.title),
),
正文:中(
子:列(
mainAxisAlignment:mainAxisAlignment.center,
儿童:[
动画生成器(
动画:angleController,
建筑商:(u,孩子){
返回Transform.rotate(
角度:angleController.value*pi*2,
孩子:孩子,
);
},
儿童:手势检测器(
onTap:(){
angleController.stop();
},
子:图标(
图标。前进,
颜色:颜色。粉红色,
尺寸:100.0,
)),
),
],
),
),
);
}
}
import 'package:flutter/material.dart';
import 'dart:math';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage>
with SingleTickerProviderStateMixin {
AnimationController angleController;
@override
void initState() {
super.initState();
angleController =
AnimationController(vsync: this, duration: Duration(seconds: 3));
angleController.repeat();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
AnimatedBuilder(
animation: angleController,
builder: (_, child) {
return Transform.rotate(
angle: angleController.value * pi * 2,
child: child,
);
},
child: GestureDetector(
onTap: () {
angleController.stop();
},
child: Icon(
Icons.forward,
color: Colors.pink,
size: 100.0,
)),
),
],
),
),
);
}
}