我遇到的问题是,当我向列的子级中添加某个小部件时,我会不断出现“无限像素底部溢出”的问题。在添加名为countdown
的新窗口小部件之前,现在是这样:
以下是我添加countdown
之后发生的事情:
这是屏幕下半部分的代码,我在其中添加countdown
:
final countdown = Countdown();
final quizBottomContent = SingleChildScrollView(
child: Container(
width: MediaQuery.of(context).size.width,
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[quizBottomContentText, quizOptions, countdown],
),
)
);
这是倒数计时小部件:
import 'package:flutter/material.dart';
import 'dart:math' as math;
class Countdown extends StatefulWidget {
@override
CountdownState createState() => CountdownState();
}
class CountdownState extends State<Countdown> with TickerProviderStateMixin {
AnimationController controller;
String get timerString {
Duration duration = controller.duration * controller.value;
return '${duration.inMinutes}:${(duration.inSeconds % 60).toString().padLeft(2, '0')}';
}
@override
void initState() {
super.initState();
controller = AnimationController(
vsync: this,
duration: Duration(seconds: 10),
);
}
@override
Widget build(BuildContext context) {
ThemeData themeData = Theme.of(context);
return Scaffold(
body: Padding(
padding: EdgeInsets.all(8.0),
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Expanded(
child: Align(
alignment: FractionalOffset.center,
child: AspectRatio(
aspectRatio: 1.0,
child: Stack(
children: <Widget>[
Positioned.fill(
child: AnimatedBuilder(
animation: controller,
builder: (BuildContext context, Widget child) {
return CustomPaint(
painter: TimerPainter(
animation: controller,
backgroundColor: Colors.white,
color: themeData.indicatorColor,
));
},
),
),
Align(
alignment: FractionalOffset.center,
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Text(
"Count Down",
style: themeData.textTheme.subhead,
),
AnimatedBuilder(
animation: controller,
builder: (BuildContext context, Widget child) {
return Text(
timerString,
style: themeData.textTheme.display4,
);
}),
],
),
),
],
),
),
),
),
Container(
margin: EdgeInsets.all(8.0),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
FloatingActionButton(
child: AnimatedBuilder(
animation: controller,
builder: (BuildContext context, Widget child) {
return Icon(controller.isAnimating
? Icons.pause
: Icons.play_arrow);
},
),
onPressed: () {
if (controller.isAnimating)
controller.stop();
else {
controller.reverse(
from: controller.value == 0.0
? 1.0
: controller.value);
}
},
)
],
),
)
],
),
),
);
}
}
class TimerPainter extends CustomPainter {
TimerPainter({
this.animation,
this.backgroundColor,
this.color,
}) : super(repaint: animation);
final Animation<double> animation;
final Color backgroundColor, color;
@override
void paint(Canvas canvas, Size size) {
Paint paint = Paint()
..color = backgroundColor
..strokeWidth = 5.0
..strokeCap = StrokeCap.round
..style = PaintingStyle.stroke;
canvas.drawCircle(size.center(Offset.zero), size.width / 2.0, paint);
paint.color = color;
double progress = (1.0 - animation.value) * 2 * math.pi;
canvas.drawArc(Offset.zero & size, math.pi * 1.5, -progress, false, paint);
}
@override
bool shouldRepaint(TimerPainter old) {
return animation.value != old.animation.value ||
color != old.color ||
backgroundColor != old.backgroundColor;
}
}
某些情况: 倒数基本上是带有动画的计时器,而倒数我是从link中提取的。因此计时器将位于按钮下方。
答案 0 :(得分:1)
尝试设置列的mainaxissize
mainAxisSize: MainAxisSize.min,
更新
好的,因此,如果您尝试将Countdown小部件作为一列中的小部件,则可以从count down小部件的构建方法中删除支架并将其包装在容器中并定义高度
return Scaffold(
body: Padding(
padding: EdgeInsets.all(8.0),
child: Column(
到
return Container(
height: 100,
child: Padding(
padding: EdgeInsets.all(8.0),
child: Column(
答案 1 :(得分:1)
我有类似的问题,包装 quizBottomContent
使用 Expanded
小部件为我解决了这个问题:
final quizBottomContent = Expanded(
child: SingleChildScrollView(
...
)
);
答案 2 :(得分:-2)
只需用容器包装该小部件并指定高度即可