flutter 底部溢出无限像素

Question

我遇到了这个问题，当我将某个小部件添加到列的子项时，我不断收到“底部被无限像素溢出”的问题。现在这是添加名为 countdown 的新小部件之前的样子:

下面是我添加countdown之后发生的事情:

这是屏幕下半部分的代码，我在其中添加了 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;
  }
}

一些背景:倒计时基本上是一个带有动画的计时器，我从这个 link 中提取了倒计时。 .因此计时器将位于按钮下方。

Answer 1

尝试设置列的 mainaxissizemainAxisSize: MainAxisSize.min,

更新

好的，所以如果您尝试将倒计时小部件作为列中的小部件，您可以从倒计时小部件的构建方法中删除脚手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(