我目前正在做一个flutter教程在android工作室，我有这个问题，我试图创建一个类，试图成为一个变量，但没有运气，我也命名了一个文件“raised_button.dart”，并使用stful小部件，看看它是否工作，但它不工作这是我的代码：
import 'package:flutter/material.dart';
import 'package:percent_indicator/circular_percent_indicator.dart';
import 'dart:async';
void main() => runApp(MaterialApp(
debugShowCheckedModeBanner: false,
home: Pomodoro(),
));
class Pomodoro extends StatefulWidget {
const Pomodoro({Key? key}) : super(key: key);
@override
State<Pomodoro> createState() => _PomodoroState();
}
class _PomodoroState extends State<Pomodoro> {
double percent = 0;
static int TimeInMinut = 240;
int TimeInSec = TimeInMinut * 60;
late Timer timer;
_StartTimer(){
TimeInMinut = 240;
int Time = TimeInMinut *60;
double SecPercent = (Time/100);
timer = Timer.periodic(Duration(seconds:1), (timer) {
setState((){
if(Time > 0){
Time--;
if(Time % 60 ==0){
TimeInMinut --;
}if(Time % SecPercent == 0){
if(percent <1){
percent += 0.01;
}else{
percent = 1;
}
}
}else{
percent = 0;
TimeInMinut = 240;
timer.cancel();
}
});
});
}
@override
Widget build(BuildContext context) {
return SafeArea(
child: Scaffold(
body: Container(
decoration: BoxDecoration(
gradient: LinearGradient(
colors: [Colors.orangeAccent, Colors.redAccent],
begin: FractionalOffset(0.5,1)
)
),
width: double.infinity,
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Padding(
padding: EdgeInsets.only(top: 25.0),
child: Text(
"Pomodoro Clock",
style: TextStyle(
color: Colors.white,
fontSize: 40.0
),
),
),
Expanded(
child: CircularPercentIndicator(
percent: percent,
animation: true,
animateFromLastPercent: true,
radius: 150.0,
lineWidth: 20.0,
progressColor: Colors.white,
center: Text(
"$TimeInMinut",
style: TextStyle(
color: Colors.white,
fontSize: 80.0
),
),
),
),
SizedBox(height: 10.0,),
Expanded(
child: Container(
width: double.infinity,
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.only(topRight: Radius.circular(30.0),topLeft: Radius.circular(30.0))
),
child: Padding(
padding: EdgeInsets.only(top: 30.0, left: 20.0, right: 20.0),
child: Column(
children: <Widget>[
Expanded(
child: Row(
children: <Widget>[
Expanded(
child: Column(
children: <Widget>[
Text(
"Focus Time",
style: TextStyle(
fontSize: 20.0,
),
),
SizedBox(height: 10.0,),
Text(
"240",
style: TextStyle(
fontSize: 50.0
),
),
]
),
),
Expanded(
child: Column(
children: <Widget>[
Text(
"Pause Time",
style: TextStyle(
fontSize: 20.0,
),
),
SizedBox(height: 10.0,),
Text(
"20",
style: TextStyle(
fontSize: 50.0
),
),
]
),
)
],
)
),
Padding(
padding: EdgeInsets.symmetric(vertical: 28.0),
child: raisedButton(
onPressed: _StartTimer,
color: Colors.redAccent,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(100.0),
),
child: Padding(
padding: EdgeInsets.all(20.0),
child: Text("Start focusing",
style: TextStyle(
color: Colors.white,
fontSize: 22.0
),
),
)
),
)
],
)
),
),
),
],
),
),
),
);
}
}这就是终端显示的
lib/main.dart:151:38: Error: The method 'raisedButton' isn't defined for the class '_PomodoroState'.
- '_PomodoroState' is from 'package:pomodoris/main.dart' ('lib/main.dart').
Try correcting the name to the name of an existing method, or defining a method named 'raisedButton'.
child: raisedButton(在这种特殊情况下我该怎么办？先谢谢你。
4条答案
按热度按时间ibrsph3r1#
大写字母R是
RaisedButton不是raisedButton。但是，
RaisedButton已过时。你想使用
ElevatedButton，你还需要把你的样式转移到new style属性，在这里你把颜色等传递给ElevatedButton.styleFrom（）构造函数。然而...这个外观也是根据Flutter所遵循的材料指南来设计的。在这里看看如何让按钮看起来漂亮而现代：https://material.io/components/buttons所有的名称也是Flutter中小部件的名称。如果你在那里卡住了，随时可以再问一次！
aoyhnmkz2#
我想人们应该看看你的raisedButton类，如果它是一个单独的类，这里应该有一个import，但它不是，类名应该以大写字母开头
ddhy6vgd3#
RaisedButton在最新的flutter版本中已弃用。您可以将RaisedButton替换为ElevatedButton
efzxgjgh4#
Flutter新版本不再使用RaisedButton
相反，您可以使用提升按钮